Megan Lord

Encapsulation of low molecular weight heparin (bemiparin) into polymeric nanoparticles obtained from cationic block copolymers: properties and cell activity

Publisher: Royal Society of Chemistry (RSC)

Date: 2013

DOI: 10.1039/C2TB00194B

The effect of silica nanoparticulate coatings on serum protein adsorption and cellular response

Publisher: Elsevier BV

Date: 10-2006

DOI: 10.1016/J.BIOMATERIALS.2006.05.037

Abstract: Serum protein adsorption on colloidal silica surfaces was investigated using a quartz crystal microbalance with dissipation (QCM-D) monitoring. The amount of serum proteins adsorbed on colloidal silica-coated surfaces was not significantly different from the control silica surfaces, with the exception of 21nm colloidal silica which experienced significantly less (P<0.05) fibrinogen adsorption compared with control silica. The adhesion and proliferation of human endothelial cells (C11STH) on nano-scale colloidal silica surfaces were significantly reduced compared with control silica surfaces, suggesting that the conformation of adsorbed proteins on the colloidal silica surfaces plays a role in modulating the amount of cell binding. Fibronectin is one of the main extracellular matrix proteins involved in endothelial cell attachment to biomaterial surfaces. There was reduced binding of a monoclonal anti-fibronectin antibody, that reacted specifically with the cell-binding fragment, to fibronectin-coated colloidal silica surfaces compared with control silica surfaces. This suggests that the fibronectin adsorbed on the colloidal silica-coated surfaces was conformationally changed compared with control silica reducing the availability of the cell-binding domain of fibronectin.

Hyaluronidase-4 is produced by mast cells and can cleave serglycin chondroitin sulfate chains into lower molecular weight forms

Publisher: Elsevier BV

Date: 07-2019

DOI: 10.1074/JBC.RA119.008647

Correlation between Molecular Weight and Branch Structure of Glycopolymers Stars and Their Binding to Lectins

Publisher: American Chemical Society (ACS)

Date: 07-01-2015

DOI: 10.1021/MA501742V

Not All Lubricin Isoforms Are Substituted with a Glycosaminoglycan Chain

Publisher: Informa UK Limited

Date: 03-10-2011

DOI: 10.3109/03008207.2011.614364

Abstract: Lubricin, also referred to as superficial zone protein, has been reported to be a proteoglycan. However, the structure of its glycosaminoglycan chain has not been well characterized, and this study was undertaken to investigate the structure of the glycosaminoglycan chain that decorated lubricin in human synovial fluid to provide insight into its biological role. Lubricin was detected as a major band at approximately 360 kDa which co-migrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a chondroitin sulfate (CS)-containing proteoglycan that was detected by both monoclonal antibodies (MAb) 2-B-6 and MAb 3-B-3 after chondroitinase ABC treatment and keratan sulfate (KS) that was detected by MAb 5-D-4. Further analysis of lubricin-containing fractions that eluted from an anion exchange column indicated that the major population of lubricin could be separated from the CS and KS stubs which indicated that this fraction of lubricin was not decorated with glycosaminoglycan chain and was the glycoprotein form of lubricin. Lubricin present in fractions that also contained CS was found to be decorated with CS structures which were reactive with MAb 3-B-3 after chondroitinase ABC digestion using a sandwich enzyme-linked immunosorbent assay approach. Aggrecan was not found to form complexes with lubricin in synovial fluid which confirmed that the MAb 3-B-3 CS and MAb 5-D-4 KS structures decorated lubricin. These data demonstrate that lubricin present in human synovial fluid was a heterogeneous population with both glycoprotein and proteoglycan forms.

Perlecan and vascular endothelial growth factor-encoding DNA-loaded chitosan scaffolds promote angiogenesis and wound healing

Publisher: Elsevier BV

Date: 03-2017

DOI: 10.1016/J.JCONREL.2017.02.009

Abstract: The repair of dermal wounds, particularly in the diabetic population, poses a significant healthcare burden. The impaired wound healing of diabetic wounds is attributed to low levels of endogenous growth factors, including vascular endothelial growth factor (VEGF), that normally stimulate multiple phases of wound healing. In this study, chitosan scaffolds were prepared via freeze drying and loaded with plasmid DNA encoding perlecan domain I and VEGF189 and analyzed in vivo for their ability to promote dermal wound healing. The plasmid DNA encoding perlecan domain I and VEGF189 loaded scaffolds promoted dermal wound healing in normal and diabetic rats. This treatment resulted in an increase in the number of blood vessels and sub-epithelial connective tissue matrix components within the wound beds compared to wounds treated with chitosan scaffolds containing control DNA or wounded controls. These results suggest that chitosan scaffolds containing plasmid DNA encoding VEGF189 and perlecan domain I have the potential to induce angiogenesis and wound healing.

Transcriptional complexity of the HSPG2 gene in the human mast cell line, HMC-1

Publisher: Elsevier BV

Date: 04-2014

DOI: 10.1016/J.MATBIO.2013.12.005

Abstract: The mammalian HSPG2 gene encodes the proteoglycan protein core perlecan, which has important functions in biology including cell adhesion via integrins, binding to the extracellular matrix via various protein-protein interactions and binding of growth factors via the heparan sulfate chains decorating the N-terminal domain I. Here we show that, in the human mast cell line HMC-1, the transcription of this gene results in a population of mRNA that is processed in such a way to provide a relative increase of transcripts corresponding to domain V or the C-terminus compared to transcripts from either domain III or the N-terminal domain I. This paper also presents evidence of splicing of the HSPG2 gene in HMC-1 cells at exons 2/3 and after comparing this sequence with those published in various databases, a model is postulated to explain what might be happening in these cells with regard to the transcription of the HSPG2 gene. As domain V of perlecan contains the α2β1 integrin binding site that modulates angiogenesis, we hypothesize that the transcriptional control of the HSPG2 gene in mast cells to synthesize these transcripts supports their stimulatory and specific role in wound healing and tissue regeneration.

Glycosaminoglycan functionalized nanoparticles exploit glycosaminoglycan functions

Publisher: Springer New York

Date: 24-09-2015

DOI: 10.1007/978-1-4939-1714-3_44

Abstract: Nanoparticles are being explored for a variety of applications including medical imaging, drug delivery, and biochemical detection. Surface functionalization of nanoparticles with glycosaminoglycans (GAGs) is an attractive strategy that is only starting to be investigated to improve their properties for biological and therapeutic applications. Herein, we describe a method to functionalize the surface of cerium oxide nanoparticles (nanoceria) with organosilane linkers, such as 3-(aminopropyl)triethoxysilane (APTES) and 3-(mercaptopropyl)trimethoxysilane (MPTMS), and GAGs, such as unfractionated and low molecular weight heparin. Ex les of how the activity of these heparin functionalized nanoparticles are governed by the pendant GAGs are detailed. The activity of heparin covalently attached to the nanoceria was found to be unchanged when compared to unfractionated heparin using the activated partial clotting time (APTT) assay.

Tuning the intentional corona of cerium oxide nanoparticles to promote angiogenesis via fibroblast growth factor 2 signalling

Publisher: Oxford University Press (OUP)

Date: 2022

DOI: 10.1093/RB/RBAC081

Abstract: Inadequate angiogenesis is a hallmark of conditions including cardiovascular diseases, stroke and chronic diabetic wounds, which exhibit tissue ischaemia ensuring that therapeutic strategies to promote angiogenesis are of great interest. However, many angiogenic treatments involve the delivery of growth factors which have limited clinical success due to poor stability, high manufacturing cost and poor efficacy. Cerium oxide nanoparticles (nanoceria) can either promote or inhibit angiogenesis depending on their surface corona chemistry. Here, nanoceria were functionalized with an intentional heparin corona, a polysaccharide which binds and signals growth factors, of different chain lengths and surface grafting density to establish their effect on angiogenesis. These nanoparticles promoted angiogenesis in vivo with the surface grafting density positively correlated with angiogenesis over the widest concentration range however, chain length did not play a role. The heparin–nanoceria supported fibroblast growth factor 2 (FGF2) signalling in vitro and promoted FGF2-mediated angiogenesis in vivo. The nanoparticles were internalized by endothelial cells in vitro where they trafficked to the lysosomes and reduced cell viability suggesting that the angiogenic activity of heparin–nanoceria is mediated in the extracellular environment. Together, this study adds to our knowledge of the angiogenic effects of heparin–nanoceria towards finding new angiogenic treatments.

Recombinant Domain V of Human Perlecan Is a Bioactive Vascular Proteoglycan

Publisher: Wiley

Date: 19-09-2017

DOI: 10.1002/BIOT.201700196

Abstract: The C-terminal domain V of the extracellular matrix proteoglycan perlecan plays unique and often ergent roles in a number of biological processes, including angiogenesis, vascular cell interactions, wound healing, and autophagy. Recombinant forms of domain V have been proposed as therapeutic agents for the treatment of cancer, stroke, and the development of cardiovascular devices and bioartificial tissues. However, the effect of domain V appears to be related to the differences in domain V structure and function observed in different expression systems and environments and exactly how this occurs is not well understood. In this study, the sequence from amino acid 3626 to 4391 of the perlecan protein core, which includes domain V, is expressed in HEK-293 cells and purified as a secreted product from conditioned media. This recombinant domain V (rDV) is expressed as a proteoglycan decorated with heparan sulfate and chondroitin sulfate chains and supports endothelial cell interactions to the same extent as full-length perlecan. This expression system serves as an important model of recombinant proteoglycan expression, as well as a source of biologically active rDV for therapeutic applications.

Fabrication of Semiordered Nanopatterned Diamond-like Carbon and Titania Films for Blood Contacting Applications

Publisher: American Chemical Society (ACS)

Date: 08-03-2016

DOI: 10.1021/ACSAMI.5B11614

Abstract: Biomaterials with the ability to interface with, but not activate, blood components are essential for a multitude of medical devices. Diamond-like carbon (DLC) and titania (TiO2) have shown promise for these applications however, both support platelet adhesion and activation. This study explored the fabrication of nanostructured DLC and TiO2 thin film coatings using a block copolymer deposition technique that produced semiordered nanopatterns with low surface roughness (5-8 nm Rrms). These surfaces supported fibrinogen and plasma protein adsorption that predominantly adsorbed between the nanofeatures and reduced the overall surface roughness. The conformation of the adsorbed fibrinogen was altered on the nanopatterned surfaces as compared with the planar surfaces to reveal higher levels of the platelet binding region. Planar DLC and TiO2 coatings supported less platelet adhesion than nanopatterned DLC and TiO2. However, platelets on the nanopatterned DLC coatings were less spread indicating a lower level of platelet activation on the nanostructured DLC coatings compared with the planar DLC coatings. These data indicated that nanostructured DLC coatings may find application in blood contacting medical devices in the future.

Recombinant production of proteoglycans and their bioactive domains

Publisher: Wiley

Date: 18-03-2013

DOI: 10.1111/FEBS.12197

Abstract: Proteoglycans are ubiquitous dynamic molecules that are made up of a protein core to which specific linear glycosylation structures, known as glycosaminoglycans, have been covalently coupled. They have roles in many biological and pathological processes, which have been shown to be dependent on events involving the protein component and/or the glycosaminoglycan chains. This review focuses on the literature describing the recombinant expression and production of proteoglycans known to be present in the extracellular, cell surface and intracellular environments with an emphasis on how the structure of the molecule relates to its biological function and how this relationship has been explored using recombinant DNA technology for clinical applications.

Elucidating the Binding Mechanism of a Novel Silica-Binding Peptide

Publisher: MDPI AG

Date: 18-12-2019

DOI: 10.3390/BIOM10010004

Abstract: Linker-protein G (LPG) is a bifunctional fusion protein composed of a solid-binding peptide (SBP, referred as the “linker”) with high affinity to silica-based compounds and a Streptococcus protein G (PG), which binds antibodies. The binding mechanisms of LPG to silica-based materials was studied using different biophysical techniques and compared to that of PG without the linker. LPG displayed high binding affinity to a silica surface (KD = 34.77 ± 11.8 nM), with a vertical orientation, in comparison to parent PG, which exhibited no measurable binding affinity. Incorporation of the linker in the fusion protein, LPG, had no effect on the antibody-binding function of PG, which retained its secondary structure and displayed no alteration of its chemical stability. The LPG system provided a milder, easier, and faster affinity-driven immobilization of antibodies to inorganic surfaces when compared to traditional chemical coupling techniques.

Mast Cells Produce a Unique Chondroitin Sulfate Epitope.

Publisher: SAGE Publications

Date: 19-11-2016

DOI: 10.1369/0022155415620649

Abstract: The granules of mast cells contain a myriad of mediators that are stored and protected by the sulfated glycosaminoglycan (GAG) chains that decorate proteoglycans. Whereas heparin is the GAG predominantly associated with mast cells, mast cell proteoglycans are also decorated with heparan sulfate and chondroitin sulfate (CS). This study investigated a unique CS structure produced by mast cells that was detected with the antibody clone 2B6 in the absence of chondroitinase ABC digestion. Mast cells in rodent tissue sections were characterized using toluidine blue, Leder stain and the presence of mast cell tryptase. The novel CS epitope was identified in rodent tissue sections and localized to cells that were morphologically similar to cells chemically identified as mast cells. The rodent mast cell-like line RBL-2H3 was also shown to express the novel CS epitope. This epitope co-localized with multiple CS proteoglycans in both rodent tissue and RBL-2H3 cultured cells. These findings suggest that the novel CS epitope that decorates mast cell proteoglycans may play a role in the way these chains are structured in mast cells.

Cellular uptake and reactive oxygen species modulation of cerium oxide nanoparticles in human monocyte cell line U937

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.1016/J.BIOMATERIALS.2012.07.024

Abstract: Cerium oxide nanoparticles (nanoceria) are promising materials for intracellular oxygen free radical scavenging providing a potential therapy for reactive oxygen species (ROS)-mediated inflammatory processes. In this study rhombohedral-shaped nanoceria were synthesized by flame spray pyrolysis with tuneable particle diameters between 3 and 94 nm by changing the liquid precursor flow rate. Monocytes and macrophages are major players in inflammatory processes as their production of ROS species has important downstream effects on cell signalling. Therefore, this study examined the ability of the nanoceria to be internalised by the human monocytic cell line, U937, and scavenge intracellular ROS. U937 cells activated in the presence of phorbol 12-myristate 13-acetate (PMA) were found to be more responsive to the nanoceria than U937 cells, which may not be surprising given the role of monocyte/macrophages in phagocytosing foreign material. The smaller particles were found to contain more crystal lattice defects with which to scavenge ROS, however a greater proportion of both the U937 and activated U937 cell populations responded to the larger particles. Hence all nanoceria particle sizes examined in this study were equally effective in scavenging intracellular ROS.

Platelet factor 4 binds to vascular proteoglycans and controls both growth factor activities and platelet activation

Publisher: Elsevier BV

Date: 03-2017

DOI: 10.1074/JBC.M116.760660

The Role of Heparan Sulfate in Inflammation, and the Development of Biomimetics as Anti-Inflammatory Strategies

Publisher: SAGE Publications

Date: 2018

DOI: 10.1369/0022155417740881

Comparing perilymph proteomes across species

Publisher: Wiley

Date: 02-11-2017

DOI: 10.1002/LARY.26885

Abstract: Biological components of perilymph affect the electrical performance of cochlear implants. Understanding the perilymph composition of common animal models will improve the understanding of this impact and improve the interpretation of results from animal studies and how it relates to humans. Analysis and comparison of the proteomes of human, guinea pig, and cat perilymph. Multiple perilymph s les from both guinea pigs and cats were analysed via liquid chromatography with tandem mass spectrometry. Proteins were identified using the Mascot database. Human data were obtained from a published dataset. Proteins identified were refined to form a proteome for each species. Over 200 different proteins were found per species. There were 81, 39, and 64 proteins in the final human, guinea pig, and cat proteomes, respectively. Twenty-one proteins were common to all three species. Fifty-two percent of the cat proteome was found in the human proteome, and 31% of the guinea pig was common to human. The cat proteome had similar complexity to the human proteome in three protein classes, whereas the guinea pig had a similar complexity in two. The presence of albumin was significantly higher in human perilymph than in the other two species. Immunoglobulins were more abundant in the human than in the cat proteome. Perilymph proteomes were compared across three species. The degree of crossover of proteins of both guinea pig and cat with human indicate that these animals suitable models for the human cochlea, albeit the cat perilymph is a closer match. NA. Laryngoscope, 128:E47-E52, 2018.

Hyaluronan coated cerium oxide nanoparticles modulate CD44 and reactive oxygen species expression in human fibroblasts

Publisher: Wiley

Date: 21-03-2016

DOI: 10.1002/JBM.A.35704

Abstract: Cerium oxide nanoparticles are being widely explored for cell therapies. In this study, nanoceria was functionalized with hyaluronan (HA) using the organosilane linker, 3-aminopropyltriethoxysilane. HA-nanoceria was found to be cytocompatible and to reduce intracellular reactive oxygen species in human fibroblasts. The HA-nanoceria was found to colocalize with CD44 on the surface of the cells and once internalized traffic to the lysosomes, be degraded and induce markers of autophagy. These particles were also effective in reducing the cell surface expression of CD44. Together these data suggest that HA-nanoceria is a promising drug delivery material to target CD44-expressing cells through a variety of mechanisms. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1736-1746, 2016.

Chitosan-Based Heparan Sulfate Mimetics Promote Epidermal Formation in a Human Organotypic Skin Model

Publisher: Wiley

Date: 24-07-2018

DOI: 10.1002/ADFM.201802818

Redox Active Cerium Oxide Nanoparticles: Current Status and Burning Issues

Publisher: Wiley

Date: 06-08-2021

DOI: 10.1002/SMLL.202102342

Abstract: Research on cerium oxide nanoparticles (nanoceria) has captivated the scientific community due to their unique physical and chemical properties, such as redox activity and oxygen buffering capacity, which made them available for many technical applications, including biomedical applications. The redox mimetic antioxidant properties of nanoceria have been effective in the treatment of many diseases caused by reactive oxygen species (ROS) and reactive nitrogen species. The mechanism of ROS scavenging activity of nanoceria is still elusive, and its redox activity is controversial due to mixed reports in the literature showing pro‐oxidant and antioxidant activity. In light of its current research interest, it is critical to understand the behavior of nanoceria in the biological environment and provide answers to some of the critical and open issues. This review critically analyzes the status of research on the application of nanoceria to treat diseases caused by ROS. It reviews the proposed mechanism of action and shows the effect of surface coatings on its redox activity. It also discusses some of the crucial issues in deciphering the mechanism and redox activity of nanoceria and suggests areas of future research.

Substrate elasticity provides mechanical signals for the expansion of hemopoietic stem and progenitor cells

Publisher: Springer Science and Business Media LLC

Date: 10-2010

DOI: 10.1038/NBT.1687

Abstract: Surprisingly little is known about the effects of the physical microenvironment on hemopoietic stem and progenitor cells. To explore the physical effects of matrix elasticity on well-characterized primitive hemopoietic cells, we made use of a uniquely elastic biomaterial, tropoelastin. Culturing mouse or human hemopoietic cells on a tropoelastin substrate led to a two- to threefold expansion of undifferentiated cells, including progenitors and mouse stem cells. Treatment with cytokines in the presence of tropoelastin had an additive effect on this expansion. These biological effects required substrate elasticity, as neither truncated nor cross-linked tropoelastin reproduced the phenomenon, and inhibition of mechanotransduction abrogated the effects. Our data suggest that substrate elasticity and tensegrity are important mechanisms influencing hemopoietic stem and progenitor cell subsets and could be exploited to facilitate cell culture.

Mast cells produce novel shorter forms of perlecan that contain functional endorepellin a role in angiogenesis and wound healing

Publisher: Elsevier BV

Date: 02-2013

DOI: 10.1074/JBC.M112.387811

Enhanced Osteogenic Differentiation of Human Fetal Cartilage Rudiment Cells on Graphene Oxide-PLGA Hybrid Microparticles

Publisher: MDPI AG

Date: 30-07-2019

DOI: 10.3390/JFB10030033

Abstract: Poly(d,l–lactide–co–glycolide) (PLGA) has been extensively explored for bone regeneration applications however, its clinical use is limited by low osteointegration. Therefore, approaches that incorporate osteoconductive molecules are of great interest. Graphene oxide (GO) is gaining popularity for biomedical applications due to its ability to bind biological molecules and present them for enhanced bioactivity. This study reports the preparation of PLGA microparticles via Pickering emulsification using GO as the sole surfactant, which resulted in hybrid microparticles in the size range of 1.1 to 2.4 µm based on the ratio of GO to PLGA in the reaction. Furthermore, this study demonstrated that the hybrid GO-PLGA microparticles were not cytotoxic to either primary human fetal cartilage rudiment cells or the human osteoblast-like cell line, Saos-2. Additionally, the GO-PLGA microparticles promoted the osteogenic differentiation of the human fetal cartilage rudiment cells in the absence of exogenous growth factors to a greater extent than PLGA alone. These findings demonstrate that GO-PLGA microparticles are cytocompatible, osteoinductive and have potential as substrates for bone tissue engineering.

Size effects of self-assembled block copolymer spherical micelles and vesicles on cellular uptake in human colon carcinoma cells

Publisher: Royal Society of Chemistry (RSC)

Date: 2014

DOI: 10.1039/C3TB21751E

Abstract: Block copolymers, poly(oligo ethylene glycol methyl ether methacrylate)- block -poly(styrene), POEGMEMA- b -PS, with various block lengths were prepared via RAFT polymerization and subsequently self-assembled into various aggregates to investigate their uptake ability into cancer cells.

De Novo Engineering of Metal–Organic Framework‐Printed In Vitro Diagnostic Devices for Specific Capture and Release of Tumor Cells

Publisher: Wiley

Date: 29-09-2021

DOI: 10.1002/SMLL.202103590

Abstract: Herein, a paper‐based in vitro diagnostic device (IVD) is developed via inkjet printing of de novo engineered, boronic acid‐rich metal–organic frameworks (BMOFs). The newly developed BMOFs simultaneously possess crystalline and amorphous structure, mesopore size, large surface area, and retain a high level of boronic acid integration. After printing the BMOFs on the filter paper, the BMOF‐printed paper IVD shows a rapid response time (40 min) towards cancer cell capture and its maximum cell capture capacity reaches approximately (4.5 ±1.1) ×10 4 cells cm −2 . Furthermore, the BMOF‐printed IVD shows nine times higher capture ability of cancer cells than non‐cancerous cells, suggesting its excellent selectivity. Importantly, the pH‐tunable affinity of BMOF to glucose enables its dual‐responsive behavior without affecting cell viability. In addition, a desired cell pattern could be achieved by directly drawing BMOFs onto a silicon substrate, highlighting its capacity as a miniaturized device for tumor cell capture and analysis. This simple and label‐free nanoplatform enables new opportunities for designing MOF‐based smart devices for erse biomedical applications such as a cost‐effective IVD technologies for cancer diagnosis, genotyping, and prognosis.

Endocytosis of cerium oxide nanoparticles and modulation of reactive oxygen species in human ovarian and colon cancer cells

Publisher: Elsevier BV

Date: 03-2017

DOI: 10.1016/J.ACTBIO.2016.12.010

Abstract: Cerium oxide nanoparticles (nanoceria) are widely reported to be cytocompatible and modulate intracellular reactive oxygen species (ROS) in a range of different cell types. In this study, nanoceria (d=7 and 94nm) synthesised by flame spray pyrolysis did not affect the proliferation of SKOV3 human ovarian and WiDr human colon cancer cell lines over a 72h treatment period. The cellular accumulation of nanoceria was uniform and increased up to 24h post-treatment before decreasing. The uptake of nanoceria in both cell lines was energy-dependent and was found to occur via non-specific pathways as well as clathrin-coated vesicles and caveolae. Nanoceria were localised predominantly in the cytoplasm and, to a lesser extent, with clathrin, caveolin-1 and lysosomes. The intracellular trafficking varied with particle size, treatment time and cell type. The larger nanoceria were found to scavenge intracellular ROS to a greater extent than the smaller nanoceria, and ROS scavenging was found to increase with treatment time. Together these data demonstrated that the diameter of the nanoceria and the cell types determined their mechanisms of uptake and intracellular localisation, as well as their ROS scavenging effects. Cerium oxide nanoparticles (nanoceria) are a promising biomaterial that can catalytically scavenge reactive oxygen species (ROS). Modulation of ROS may potentially minimise the inflammatory effects of cancer. However, the antioxidant properties of nanoceria are reported to be pH-dependent and, thus, dependent on their mechanisms of endocytosis. This study is the first to examine the effects of particle size on the uptake and intracellular trafficking of flame spray-synthesised nanoceria in human cancer cells. This study demonstrated that the particle diameter, treatment time and cell type determined the mechanisms of uptake and intracellular localisation of nanoceria, as well as their ROS scavenging effects. This study highlighted the importance of testing new nanoparticle systems rather than making assumptions based on previous uptake studies.

The cartilage matrix molecule components produced by human foetal cartilage rudiment cells within scaffolds and the role of exogenous growth factors

Publisher: Elsevier BV

Date: 06-2012

DOI: 10.1016/J.BIOMATERIALS.2012.02.032

Abstract: Development of cartilage lesions in osteoarthritis and following traumatic injury has important consequences on the weight bearing and articulation of joints, has severe impact on the quality of life of affected in iduals and is of significant socioeconomic impact. Hyaline cartilage is a highly specialised tissue with a limited ability to self repair. Development of three-dimensional scaffolds which maintain the correct chondrocyte phenotype during expansion of cells in vitro and their application in regenerative strategies for cartilage repair is therefore a major research objective of many laboratories. This study examined the matrix components elaborated by cultured foetal cartilage rudiment cells, a mixture of chondroblasts/chondroprogenitor cells and committed chondrocytes, in monolayer, cell pellet cultures and in the synthetic scaffolds sodium alginate and polyglycolic acid (PGA). The ability of fibroblast growth factor (FGF)-2 and FGF-18 to promote chondrogenesis in pellet cultures was also examined. While the scaffolds did not completely replicate the matrix organisation evident in native cartilage, type II collagen and aggrecan were nevertheless prominent matrix components. FGF-2 and FGF-18 further promoted the production of cartilage-specific matrix components in pellet culture as FGF-18 stimulated the production of type X collagen and perlecan and may be indicative of a more terminally differentiated phenotype induced in the rudiment cells with this growth factor.

Structure-Activity Relationships of Bioengineered Heparin/Heparan Sulfates Produced in Different Bioreactors

Publisher: MDPI AG

Date: 15-05-2017

DOI: 10.3390/MOLECULES22050806

Abstract: Heparin and heparan sulfate are structurally-related carbohydrates with therapeutic applications in anticoagulation, drug delivery, and regenerative medicine. This study explored the effect of different bioreactor conditions on the production of heparin/heparan sulfate chains via the recombinant expression of serglycin in mammalian cells. Tissue culture flasks and continuously-stirred tank reactors promoted the production of serglycin decorated with heparin/heparan sulfate, as well as chondroitin sulfate, while the serglycin secreted by cells in the tissue culture flasks produced more highly-sulfated heparin/heparan sulfate chains. The serglycin produced in tissue culture flasks was effective in binding and signaling fibroblast growth factor 2, indicating the utility of this molecule in drug delivery and regenerative medicine applications in addition to its well-known anticoagulant activity.

The cartilage extracellular matrix as a transient developmental scaffold for growth plate maturation

Publisher: Elsevier BV

Date: 05-2016

DOI: 10.1016/J.MATBIO.2016.01.008

Abstract: The cartilage growth plate is a specialized developmental tissue containing characteristic zonal arrangements of chondrocytes. The proliferative and differentiative states of chondrocytes are tightly regulated at all stages including the initial limb bud and rudiment cartilage stages of development, the establishment of the primary and secondary ossification centers, development of the growth plates and laying down of bone. A multitude of spatio-temporal signals, including transcription factors, growth factors, morphogens and hormones, control chondrocyte maturation and terminal chondrocyte differentiation/hypertrophy, cell death/differentiation, calcification and vascular invasion of the growth plate and bone formation during morphogenetic transition of the growth plate. This involves hierarchical, integrated signaling from growth and factors, transcription factors, mechanosensory cues and proteases in the extracellular matrix to regulate these developmental processes to facilitate progressive changes in the growth plate culminating in bone formation and endochondral ossification. This review provides an overview of selected components which have particularly important roles in growth plate biology including collagens, proteoglycans, glycosaminoglycans, growth factors, proteases and enzymes.

ROS-Mediated Anti-Angiogenic Activity of Cerium Oxide Nanoparticles in Melanoma Cells

Publisher: American Chemical Society (ACS)

Date: 06-01-2022

DOI: 10.1021/ACSBIOMATERIALS.1C01268

Abstract: Angiogenesis plays a key role in cancer progression, including transition to the metastatic phase

Scaling deterministic lateral displacement arrays for high throughput and dilution-free enrichment of leukocytes

Publisher: IOP Publishing

Date: 28-04-2011

DOI: 10.1088/0960-1317/21/5/054024

The Effect of Oligomerization on A Solid-Binding Peptide Binding to Silica-Based Materials

Publisher: MDPI AG

Date: 30-05-2020

DOI: 10.3390/NANO10061070

Abstract: The bifunctional linker-protein G (LPG) fusion protein comprises a peptide (linker) sequence and a truncated form of Streptococcus strain G148 protein G (protein G). The linker represents a multimeric solid-binding peptide (SBP) comprising 4 × 21-amino acid sequence repeats that display high binding affinity towards silica-based materials. In this study, several truncated derivatives were investigated to determine the effect of the SBP oligomerization on the silica binding function of LPG (for the sake of clarity, LPG will be referred from here on as 4 × LPG). Various biophysical characterization techniques were used to quantify and compare the truncated derivatives against 4 × LPG and protein G without linker (PG). The derivative containing two sequence repeats (2 × LPG) showed minimal binding to silica, while the truncated derivative with only a single sequence (1 × LPG) displayed no binding. The derivative containing three sequence repeats (3 × LPG) was able to bind to silica with a binding affinity of KD = 53.23 ± 4.5 nM, which is 1.5 times lower than that obtained for 4 × LPG under similar experimental conditions. Circular dichroism (CD) spectroscopy and fluorescence spectroscopy studies indicated that the SBP degree of oligomerization has only a small effect on the secondary structure (the linker unravels the beginning of the protein G sequence) and chemical stability of the parent protein G. However, based on quartz crystal microbalance with dissipation monitoring (QCM-D), oligomerization is an important parameter for a strong and stable binding to silica. The replacement of three sequence repeats by a (GGGGS)12 glycine-rich spacer indicated that the overall length rather than the SBP oligomerization mediated the effective binding to silica.

Understanding the cochlear implant environment by mapping perilymph proteomes from different species

Publisher: IEEE

Date: 08-2016

DOI: 10.1109/EMBC.2016.7591908

Perlecan domain 1 recombinant proteoglycan augments BMP-2 activity and osteogenesis

Publisher: Springer Science and Business Media LLC

Date: 11-09-2012

DOI: 10.1186/1472-6750-12-60

Optimization of bioengineered heparin/heparan sulfate production for therapeutic applications

Publisher: Informa UK Limited

Date: 10-04-2017

DOI: 10.1080/21655979.2017.1301328

Longitudinal Characterization of Phagocytic and Neutralization Functions of Anti-Spike Antibodies in Plasma of Patients after Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Publisher: The American Association of Immunologists

Date: 15-10-2022

DOI: 10.4049/JIMMUNOL.2200272

Abstract: Phagocytic responses by effector cells to opsonized viruses have been recognized to play a key role in antiviral immunity. Limited data on coronavirus disease 2019 suggest that the role of Ab-dependent and -independent phagocytosis may contribute to the observed immunological and inflammatory responses however, their development, duration, and role remain to be fully elucidated. In this study of 62 acute and convalescent patients, we found that patients with acute coronavirus disease 2019 can mount a phagocytic response to autologous plasma-opsonized Spike protein–coated microbeads as early as 10 d after symptom onset, while heat inactivation of this plasma caused 77–95% abrogation of the phagocytic response and preblocking of Fc receptors showed variable 18–60% inhibition. In convalescent patients, phagocytic response significantly correlated with anti-Spike IgG titers and older patients, while patients with severe disease had significantly higher phagocytosis and neutralization functions compared with patients with asymptomatic, mild, or moderate disease. A longitudinal subset of the convalescent patients over 12 mo showed an increase in plasma Ab affinity toward Spike Ag and preservation of phagocytic and neutralization functions, despite a decline in the anti-Spike IgG titers by & %. Our data suggest that early phagocytosis is primarily driven by heat-liable components of the plasma, such as activated complements, while anti-Spike IgG titers account for the majority of observed phagocytosis at convalescence. Longitudinally, a significant increase in the affinity of the anti-Spike Abs was observed that correlated with the maintenance of both the phagocytic and neutralization functions, suggesting an improvement in the quality of the Abs.

Oxygen-Vacancy Engineering of Cerium-Oxide Nanoparticles for Antioxidant Activity

Publisher: American Chemical Society (ACS)

Date: 30-05-2019

DOI: 10.1021/ACSOMEGA.9B00521

Macrophages bind LDL using heparan sulfate and the perlecan protein core

Publisher: Elsevier BV

Date: 2021

DOI: 10.1016/J.JBC.2021.100520

The role of the cell surface glycocalyx in drug delivery to and through the endothelium

Publisher: Elsevier BV

Date: 05-2022

DOI: 10.1016/J.ADDR.2022.114195

Abstract: Cell membranes are key interfaces where materials engineering meets biology. Traditionally regarded as just the location of receptors regulating the uptake of molecules, we now know that all mammalian cell membranes are 'sugar coated'. These sugars, or glycans, form a matrix bound at the cell membrane via proteins and lipids, referred to as the glycocalyx, which modulate access to cell membrane receptors crucial for interactions with drug delivery systems (DDS). Focusing on the key blood-tissue barrier faced by most DDS to enable transport from the place of administration to target sites via the circulation, we critically assess the design of carriers for interactions at the endothelial cell surface. We also discuss the current challenges for this area and provide opportunities for future research efforts to more fully engineer DDS for controlled, efficient, and targeted interactions with the endothelium for therapeutic application.

Anti-angiogenic activity of heparin functionalised cerium oxide nanoparticles

Publisher: Elsevier BV

Date: 11-2013

DOI: 10.1016/J.BIOMATERIALS.2013.07.083

Abstract: Cerium oxide nanoparticles (nanoceria) are widely reported to be non-cytotoxic and modulate intracellular reactive oxygen species (ROS). In this study, nanoceria (dxRD = 12 nm) were functionalised with either 130 or 880 molecules of unfractionated heparin using the organosilane linker, 3-aminopropyltriethoxysilane. Nanoceria with a low level of heparin functionalisation were found to scavenge intracellular ROS to the same extent as unfunctionalised nanoceria and significantly more than cells exposed to medium only. In contrast, nanoceria with the highest level of heparin functionalisation were not as effective at scavenging intracellular ROS. Nanoceria were localised predominantly in the cytoplasm, while heparin-nanoceria were localised in both the cytoplasm and lysosomes. Together these data demonstrated that the level of nanoceria surface functionalisation with heparin determined the intracellular localisation and ROS scavenging ability of these particles. Additionally, heparin-nanoceria were effective in reducing endothelial cell proliferation indicating that they may find application in the control of angiogenesis in cancer in the future.

Parisian types of ruin probabilities for a class of dependent risk-reserve processes

Publisher: Informa UK Limited

Date: 29-06-2018

DOI: 10.1080/03461238.2018.1483420

A polyion complex micelle with heparin for growth factor delivery and uptake into cells

Publisher: Royal Society of Chemistry (RSC)

Date: 2013

DOI: 10.1039/C3TB00360D

Colocalization in vivo and association in vitro of perlecan and elastin

Publisher: Springer Science and Business Media LLC

Date: 28-08-2011

DOI: 10.1007/S00418-011-0854-7

Abstract: We have colocalized elastin and fibrillin-1 with perlecan in extracellular matrix of tensional and weight-bearing connective tissues. Elastin and fibrillin-1 were identified as prominent components of paraspinal blood vessels, and posterior longitudinal ligament in the human fetal spine and outer annulus fibrosus of the fetal intervertebral disc. We also colocalized perlecan with a synovial elastic basal lamina, where the attached synovial cells were observed to produce perlecan. Elastin, fibrillin-1 and perlecan were co-localized in the intima and media of small blood vessels in the synovium and in human fetal paraspinal blood vessels. Elastic fibers were observed at the insertion point of the anterior cruciate ligament to bone in the ovine stifle joint where they colocalized with perlecan. Elastin has not previously been reported to be spatially associated with perlecan in these tissues. Interactions between the tropoelastin and perlecan heparan sulfate chains were demonstrated using quartz crystal microbalance with dissipation solid phase binding studies. Electrostatic interactions through the heparan sulfate chains of perlecan and core protein mediated the interactions with tropoelastin, and were both important in the coacervation of tropoelastin and deposition of elastin onto perlecan immobilized on the chip surface. This may help us to understand the interactions which are expected to occur in vivo between the tropoelastin and perlecan to facilitate the deposition of elastin and formation of elastic microfibrils in situ and would be consistent with the observed distributions of these components in a number of connective tissues.

Pericellular colocalisation and interactive properties of type VI collagen and perlecan in the intervertebral disc

Publisher: European Cells and Materials

Date: 05-07-2016

DOI: 10.22203/ECM.V032A03

Abstract: The aim of this study was to immunolocalise type VI collagen and perlecan and determine their interactive properties in the intervertebral disc (IVD). Confocal laser scanning microscopy co-localised perlecan with type VI collagen as pericellular components of IVD cells and translamellar cross-bridges in ovine and murine IVDs. These cross-bridges were significantly less abundant in the heparin sulphate deficient Hspg2 exon 3 null mouse IVD than in wild type. This association of type VI collagen with elastic components provides clues as to its roles in conveying elastic recoil properties to annular tissues. Perlecan and type VI collagen were highly interactive in plasmon resonance studies. Pericellular colocalisation of perlecan and type VI collagen provides matrix stabilisation and cell-matrix communication which allows IVD cells to perceive and respond to perturbations in their biomechanical microenvironment. Perlecan, at the cell surface, provides an adhesive interface between the cell and its surrounding extracellular matrix. Elastic microfibrillar structures regulate tensional connective tissue development and function. The 2010 Global Burden of Disease study examined 291 disorders and identified disc degeneration and associated low back pain as the leading global musculoskeletal disorder emphasising its massive socioeconomic impact and the need for more effective treatment strategies. A greater understanding of how the IVD achieves its unique biomechanical functional properties is of great importance in the development of such therapeutic measures.

Importance of Polymer Length in Fructose-Based Polymeric Micelles for an Enhanced Biological Activity

Publisher: American Chemical Society (ACS)

Date: 10-01-2019

DOI: 10.1021/ACS.MACROMOL.8B02381

Biointerface: protein enhanced stem cells binding to implant surface

Publisher: Springer Science and Business Media LLC

Date: 20-06-2012

DOI: 10.1007/S10856-012-4687-2

Abstract: The number of metallic implantable devices placed every year is estimated at 3.7 million. This number has been steadily increasing over last decades at a rate of around 8 %. In spite of the many successes of the devices the implantation of biomaterial into tissues almost universally leads to the development of an avascular sac, which consists of fibrous tissue around the device and walls off the implant from the body. This reaction can be detrimental to the function of implant, reduces its lifetime, and necessitates repeated surgery. Clearly, to reduce the number of revision surgeries and improve long-term implant function it is necessary to enhance device integration by modulating cell adhesion and function. In this paper we have demonstrated that it is possible to enhance stem cell attachment using engineered biointerfaces. To create this functional interface, s les were coated with polymer (as a precursor) and then ion implanted to create a reactive interface that aids the binding of biomolecules--fibronectin. Both AFM and XPS analyses confirmed the presence of protein layers on the s les. The amount of protein was significant greater for the ion implanted surfaces and was not disrupted upon washing with detergent, hence the formation of strong bonds with the interface was confirmed. While, for non ion implanted surfaces, a decrease of protein was observed after washing with detergent. Finally, the number of stem cells attached to the surface was enhanced for ion implanted surfaces. The studies presented confirm that the developed bionterface with immobilised fibronectin is an effective means to modulate stem cell attachment.

Effect of Recombinant Human Perlecan Domain V Tethering Method on Protein Orientation and Blood Contacting Activity on Polyvinyl Chloride

Publisher: Wiley

Date: 23-04-2021

DOI: 10.1002/ADHM.202100388

Abstract: Surface modification of biomaterials is a promising approach to control biofunctionality while retaining the bulk biomaterial properties. Perlecan is the major proteoglycan in the vascular basement membrane that supports low levels of platelet adhesion but not activation. Thus, perlecan is a promising bioactive for blood‐contacting applications. This study furthers the mechanistic understanding of platelet interactions with perlecan by establishing that platelets utilize domains III and V of the core protein for adhesion. Polyvinyl chloride (PVC) is functionalized with recombinant human perlecan domain V (rDV) to explore the effect of the tethering method on proteoglycan orientation and bioactivity. Tethering of rDV to PVC is achieved via either physisorption or covalent attachment via plasma immersion ion implantation (PIII) treatment. Both methods of rDV tethering reduce platelet adhesion and activation compared to the pristine PVC, however, the mechanisms are unique for each tethering method. Physisorption of rDV on PVC orientates the molecule to hinder access to the integrin‐binding region, which inhibits platelet adhesion. In contrast, PIII treatment orientates rDV to allow access to the integrin‐binding region, which is rendered antiadhesive to platelets via the glycosaminoglycan (GAG) chain. These effects demonstrate the potential of rDV biofunctionalization to modulate platelet interactions for blood contacting applications.

Surface roughness influences the protein corona formation of glycosylated nanoparticles and alter their cellular uptake

Publisher: Royal Society of Chemistry (RSC)

Date: 2019

DOI: 10.1039/C9NR06835J

Abstract: Patterned nanoparticle surfaces can repel protein absorption and prevent the formation of a protein corona, which alters the biological behavior and therefore the fate of the nanoparticle.

Proteoglycans: Potential Agents in Mammographic Density and the Associated Breast Cancer Risk.

Publisher: Springer Science and Business Media LLC

Date: 26-10-2015

DOI: 10.1007/S10911-015-9346-Z

Abstract: Although increased mammographic density (MD) has been well established as a marker for increased breast cancer (BC) risk, its pathobiology is far from understood. Altered proteoglycan (PG) composition may underpin the physical properties of MD, and may contribute to the associated increase in BC risk. Numerous studies have investigated PGs, which are a major stromal matrix component, in relation to MD and BC and reported results that are sometimes discordant. Our review summarises these results and highlights discrepancies between PG associations with BC and MD, thus serving as a guide for identifying PGs that warrant further research towards developing chemo-preventive or therapeutic agents targeting preinvasive or invasive breast lesions, respectively.

Targeted Delivery and Redox Activity of Folic Acid-Functionalized Nanoceria in Tumor Cells

Publisher: American Chemical Society (ACS)

Date: 04-02-2018

DOI: 10.1021/ACS.MOLPHARMACEUT.7B00920

Protein adsorption on derivatives of hyaluronic acid and subsequent cellular response

Publisher: Wiley

Date: 04-11-2009

DOI: 10.1002/JBM.A.32219

Abstract: The modulation of biological interactions with artificial surfaces is a vital aspect of biomaterials research. Serum protein adsorption onto photoreactive hyaluronic acid (Hyal-N(3)) and its sulfated derivative (HyalS-N(3)) was analyzed to determine extent of protein interaction and protein conformation as well as subsequent cell adhesion. There were no significant (p < 0.01) differences in the amount of protein adsorbed to the two polymers however, proteins were found to be more loosely bound on HyalS-N(3) compared with Hyal-N(3). Fibronectin was adsorbed onto HyalS-N(3) in such an orientation as to allow the availability of the cell binding region, while there was more restricted access to this region on fibronectin adsorbed onto Hyal-N(3). This was confirmed by reduced cell adhesion on fibronectin precoated Hyal-N(3) compared with fibronectin precoated HyalS-N(3). Minimal cell adhesion was observed on albumin and serum precoated Hyal-N(3). The quartz crystal microbalance confirmed that specific cell-surface interactions were experienced by cells interacting with the fibronectin precoated polymers and serum precoated HyalS-N(3).

Surface Biofunctionalization of Silk Biomaterials Using Dityrosine Cross-Linking.

Publisher: American Chemical Society (ACS)

Date: 06-07-2022

DOI: 10.1021/ACSAMI.2C03345

Abstract: Biofunctionalization of silk biomaterial surfaces with extracellular matrix (ECM) molecules, cell binding peptides, or growth factors is important in a range of applications, including tissue engineering and development of implantable medical devices. Passive adsorption is the most common way to immobilize molecules of interest on preformed silk biomaterials but can lead to random molecular orientations and displacement from the surface, limiting their applications. Herein, we developed techniques for covalent immobilization of biomolecules using enzyme- or photoinitiated formation of dityrosine bonds between the molecule of interest and silk. Using recombinantly expressed domain V of the human basement membrane proteoglycan perlecan (rDV) as a model molecule, we demonstrated that rDV can be covalently immobilized via dityrosine cross-linking without the need to modify rDV or silk biomaterials. Dityrosine-based immobilization resulted in a different molecular orientation to passively absorbed rDV with less C- and N-terminal region exposure on the surface. Dityrosine-based immobilization supported functional rDV immobilization where immobilized rDV supported endothelial cell adhesion, spreading, migration, and proliferation. These results demonstrate the utility of dityrosine-based cross-linking in covalent immobilization of tyrosine-containing molecules on silk biomaterials in the absence of chemical modification, adding a simple and accessible technique to the silk biofunctionalization toolbox.

Microchannels Are an Architectural Cue That Promotes Integration and Vascularization of Silk Biomaterials in Vivo

Publisher: American Chemical Society (ACS)

Date: 09-02-2020

DOI: 10.1021/ACSBIOMATERIALS.9B01624

Quasi-Birth-and-Death Processes with Rational Arrival Process Components

Publisher: Informa UK Limited

Date: 04-08-2010

DOI: 10.1080/15326349.2010.498311

Experimental and theoretical tools to elucidate the binding mechanisms of solid-binding peptides

Publisher: Elsevier BV

Date: 09-2019

DOI: 10.1016/J.NBT.2019.04.001

Abstract: The interactions between biomolecules and solid surfaces play an important role in designing new materials and applications which mimic nature. Recently, solid-binding peptides (SBPs) have emerged as potential molecular building blocks in nanobiotechnology. SBPs exhibit high selectivity and binding affinity towards a wide range of inorganic and organic materials. Although these peptides have been widely used in various applications, there is a need to understand the interaction mechanism between the peptide and its material substrate, which is challenging both experimentally and theoretically. This review describes the main characterisation techniques currently available to study SBP-surface interactions and their contribution to gain a better insight for designing new peptides for tailored binding.

The role of vascular-derived perlecan in modulating cell adhesion, proliferation and growth factor signaling

Publisher: Elsevier BV

Date: 04-2014

DOI: 10.1016/J.MATBIO.2014.01.016

Bioengineered heparin

Publisher: Informa UK Limited

Date: 05-06-2014

DOI: 10.4161/BIOE.29388

Analysis of queues with rational arrival process components

Publisher: Association for Computing Machinery (ACM)

Date: 09-03-2012

DOI: 10.1145/2185395.2185422

Plasma Ion Implantation of Silk Biomaterials Enabling Direct Covalent Immobilization of Bioactive Agents for Enhanced Cellular Responses

Publisher: American Chemical Society (ACS)

Date: 07-05-2018

DOI: 10.1021/ACSAMI.8B03182

Abstract: Silk fibroin isolated from Bombyx mori cocoons is a promising material for a range of biomedical applications, but it has no inherent cell-interactive domains, necessitating functionalization with bioactive molecules. Here we demonstrate significantly enhanced cell interactions with silk fibroin biomaterials in the absence of biofunctionalization following surface modification using plasma immersion ion implantation (PIII). Further, PIII treated silk fibroin biomaterials supported direct covalent immobilization of proteins on the material surface in the absence of chemical cross-linkers. Surface analysis after nitrogen plasma and PIII treatment at 20 kV revealed that the silk macromolecules are significantly fragmented, and at the higher fluences of implanted ions, surface carbonization was observed to depths corresponding to that of the ion penetration. Consistent with the activity of radicals created in the treated surface layer, oxidation was observed on contact with atmospheric oxygen and the PIII treated surfaces were capable of direct covalent immobilization of bioactive macromolecules. Changes in thickness, amide and nitrile groups, refractive index, and extinction coefficient in the wavelength range 400-1000 nm as a function of ion fluence are presented. Reactions responsible for the restructuring of the silk surface under ion beam treatment that facilitate covalent binding of proteins and a significant improvement in cell interactions on the modified surface are proposed.

Biomaterials containing extracellular matrix molecules as biomimetic next-generation vascular grafts

Publisher: Elsevier BV

Date: 10-2023

DOI: 10.1016/J.TIBTECH.2023.09.009

The modulation of platelet adhesion and activation by chitosan through plasma and extracellular matrix proteins

Publisher: Elsevier BV

Date: 10-2011

DOI: 10.1016/J.BIOMATERIALS.2011.05.062

Abstract: Chitosan has been shown to promote initial wound closure events to prevent blood loss. Platelet adhesion and activation are crucial early events in these processes after traumatic bleeding leading to thrombus formation. Platelet adhesion to chitosan was found to be enhanced in the presence of adsorbed plasma and extracellular matrix proteins and was found to be primarily mediated by α(IIb)β(3) integrins, while α(2)β(1) integrins were found to be involved in platelet adhesion to collagen and perlecan. Platelets were found to be activated by chitosan, as shown by an increase in the expression of α(IIb)β(3) integrins and P-selectin, while the extent of activation was modulated by the presence of proteins including perlecan and fibrinogen. Collagen-coated chitosan was found to activate platelets to the same extent as either chitosan or collagen alone. These data support the role of plasma and extracellular matrix proteins in promoting chitosan mediated platelet adhesion and activation supporting the hypothesis that chitosan promotes wound healing via these interactions.

The multifaceted roles of perlecan in fibrosis

Publisher: Elsevier BV

Date: 08-2018

DOI: 10.1016/J.MATBIO.2018.02.013

Abstract: Perlecan, or heparan sulfate proteoglycan 2 (HSPG2), is a ubiquitous heparan sulfate proteoglycan that has major roles in tissue and organ development and wound healing by orchestrating the binding and signaling of mitogens and morphogens to cells in a temporal and dynamic fashion. In this review, its roles in fibrosis are reviewed by drawing upon evidence from tissue and organ systems that undergo fibrosis as a result of an uncontrolled response to either inflammation or traumatic cellular injury leading to an over production of a collagen-rich extracellular matrix. This review focuses on ex les of fibrosis that occurs in lung, liver, kidney, skin, kidney, neural tissues and blood vessels and its link to the expression of perlecan in that particular organ system.

Soluble LILRA3 promotes neurite outgrowth and synapses formation through a high-affinity interaction with Nogo 66

Publisher: The Company of Biologists

Date: 2016

DOI: 10.1242/JCS.182006

Abstract: Inhibitory proteins, particularly Nogo 66, a highly conserved 66 amino acid loop of Nogo A, play key roles in limiting the intrinsic capacity of the central nervous system to regenerate after injury. Ligation of surface Nogo receptors (NgRs) and/or leukocyte immunoglobulin like receptor B2 (LILRB2) and its mouse orthologue the paired-immunoglobulin-like receptor B (PIRB) by Nogo 66 transduces inhibitory signals that potently inhibit neurite outgrowth. Here we show that soluble leukocyte immunoglobulin-like receptor A3 (LILRA3) is a high affinity receptor for Nogo 66, suggesting that LILRA3 might be a competitive antagonist to these cell surface inhibitory receptors. Consistent with this, LILRA3 significantly reversed Nogo 66-mediated inhibition of neurite outgrowth and promoted synapse formation in primary cortical neurons via regulation of the MEK/ERK pathway. LILRA3 represents a new antagonist to Nogo 66-mediated inhibition of neurite outgrowth in the CNS, a function distinct from its immune-regulatory role in leukocytes. This report is also the first to demonstrate that a member of LILR family normally not expressed in rodents exerts functions on mouse neurons through the highly homologous Nogo 66 ligand.

The Structure, Location, and Function of Perlecan, a Prominent Pericellular Proteoglycan of Fetal, Postnatal, and Mature Hyaline Cartilages

Publisher: Elsevier BV

Date: 12-2006

DOI: 10.1074/JBC.M608462200

Dry Surface Treatments of Silk Biomaterials and Their Utility in Biomedical Applications

Publisher: American Chemical Society (ACS)

Date: 27-08-2020

DOI: 10.1021/ACSBIOMATERIALS.0C00888

Protein adsorption on derivatives of hyaluronan

Publisher: Wiley

Date: 06-2008

DOI: 10.1002/MASY.200850604

Influence of nanoscale surface topography on protein adsorption and cellular response

Publisher: Elsevier BV

Date: 02-2010

DOI: 10.1016/J.NANTOD.2010.01.001

Harnessing chondroitin sulphate in composite scaffolds to direct progenitor and stem cell function for tissue repair.

Publisher: Royal Society of Chemistry (RSC)

Date: 2018

DOI: 10.1039/C7BM01158J

Abstract: This review details the inclusion of chondroitin sulphate in bioscaffolds for superior functional properties in tissue regenerative applications.

Silk biomaterials functionalized with recombinant domain V of human perlecan modulate endothelial cell and platelet interactions for vascular applications

Publisher: Elsevier BV

Date: 12-2016

DOI: 10.1016/J.COLSURFB.2016.08.039

Abstract: Modulation of endothelial cell and platelet interactions is an essential feature of vascular materials. Silk biomaterials were functionalized with recombinantly expressed domain V of human perlecan, an essential vascular proteoglycan involved in vasculogenesis, angiogenesis and wound healing, using passive adsorption or covalent cross-linking via carbodiimide chemistry. The orientation of domain V on the surface of silk biomaterials was modulated by the immobilization technique and glycosaminoglycan chains played an essential role in the proteoglycan presentation on the material surface. Covalent immobilization supported improved integrin binding site presentation to endothelial cells compared to passive adsorption in the presence of glycosaminoglycan chains, but removal of glycosaminoglycan chains resulted in reduced integrin site availability and thus cell binding. Silk biomaterials covalently functionalized with domain V supported endothelial cell adhesion, spreading and proliferation and were anti-adhesive for platelets, making them promising surfaces for the development of the next-generation vascular grafts.

Nano‐Bio‐Chemical Braille for Cells: The Regulation of Stem Cell Responses using Bi‐Functional Surfaces

Publisher: Wiley

Date: 30-09-2014

DOI: 10.1002/ADFM.201401696

Current serological possibilities for the diagnosis of arthritis with special focus on proteins and proteoglycans from the extracellular matrix

Publisher: Informa UK Limited

Date: 08-11-2014

DOI: 10.1586/14737159.2015.979158

Abstract: This review discusses our current understanding of how the expression and turnover of components of the cartilage extracellular matrix (ECM) have been investigated, both as molecular markers of arthritis and as indicators of disease progression. The cartilage ECM proteome is well studied it contains proteoglycans (aggrecan, perlecan and inter-α-trypsin inhibitor), collagens and glycoproteins (cartilage oligomeric matrix protein, fibronectin and lubricin) that provide the structural and functional changes in arthritis. However, the changes that occur in the carbohydrate structures, including glycosaminoglycans, with disease are less well studied. Investigations of the cartilage ECM proteome have revealed many potential biomarkers of arthritis. However, a clinical diagnostic or multiplex assay is yet to be realized due to issues with specificity to the pathology of arthritis. The future search for clinical biomarkers of arthritis is likely to involve both protein and carbohydrate markers of the ECM through the application of glycoproteomics.

Perspectives on the use of biomaterials to store platelets for transfusion

Publisher: American Vacuum Society

Date: 27-05-2016

DOI: 10.1116/1.4952450

Abstract: Platelets are routinely stored enabling transfusions for a range of conditions. While the current platelet storage bags, composed of either polyvinylchloride or polyolefin, are well-established, the storage of platelets in these bags beyond 7 days reduces platelet viability below clinically usable levels. New materials and coatings that promote platelet respiration while not supporting platelet adhesion or activation have started to emerge, with the potential to enable platelet storage beyond 7 days. This review focuses on the literature describing currently used biomaterials for platelet storage and emerging materials that are showing promise for improving platelet storage.

Cell surface chondroitin sulphate proteoglycan 4 (CSPG4) binds to the basement membrane heparan sulphate proteoglycan, perlecan, and is involved in cell adhesion

Publisher: Oxford University Press (OUP)

Date: 15-02-2018

DOI: 10.1093/JB/MVY008

Can we produce heparin/heparan sulfate biomimetics using mother-nature as the gold standard?

Publisher: MDPI AG

Date: 05-03-2015

DOI: 10.3390/MOLECULES20034254

Sulfation of the Bikunin Chondroitin Sulfate Chain Determines Heavy Chain·Hyaluronan Complex Formation

Publisher: Elsevier BV

Date: 08-2013

DOI: 10.1074/JBC.M112.404186

Drug-loading of poly(ethylene glycol methyl ether methacrylate) (PEGMEMA)-based micelles and mechanisms of uptake in colon carcinoma cells

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.COLSURFB.2016.04.019

Abstract: In this study polymeric micelles formed from poly(poly(ethylene glycol) methyl ether methacrylate)-block-poly(methyl methacrylate) (P(PEGMEMA75)-b-PMMA80) block copolymer of approximately 25nm in diameter were used to encapsulate the model drug, Nile Red, with a loading efficiency of 0.08wt% and a chemotherapeutic drug, doxorubicin (DOX), with an efficiency of 2.75wt%. The release of DOX from the micelles was sufficient to be cytotoxic to human colon carcinoma cells, WiDr, while Nile Red and the unloaded micelles were found not to be cytotoxic when exposed to the cells at polymer concentrations up to 200μg/mL. Nile Red loaded micelles were used to analyze uptake of the micelles into the cells which were rapidly internalized within minutes of exposure. The three major endocytotic pathways were involved in the internalization of micelles however other passive mechanisms were also at play as the addition of inhibitors to all three pathways did not completely inhibit the uptake of these nanoparticles. These data demonstrate the potential of the P(PEGMEMA)75-b-PMMA80 block copolymer micelles to be rapidly internalized by carcinoma cells and deliver low doses of drugs intracellularly for controlled drug release.

Genetically Encoded Synthetic Beta Cells for Insulin Biosynthesis and Release under Hyperglycemic Conditions

Publisher: Wiley

Date: 20-01-2022

DOI: 10.1002/ADFM.202111271

Abstract: Advances in artificial/synthetic cells have drawn a new era of nanobiotechnology, which have shown broad prospects in biomedical applications. The rational nanoengineering of synthetic cells that can closely substitute the systematic biological functions of cells is a next grand challenge. Here, a genetically encoded synthetic beta cell, which can sense hyperglycemic conditions to initiate programmed biosynthesis and secretion of insulin is reported. By encapsulating different metal–organic framework‐based artificial organelles with distinctive bifunctionalities, the synthetic cell can undergo programmed, sequential subcellular events, including glucose sensing, initiation of insulin gene transcription and translation, and finally excretion of functional insulin, under hyperglycemic conditions. Glucose uptake assay suggests that the insulin produced by the synthetic cells can successfully promote glucose uptake into mammalian cells. The construction of a higher‐order cell cluster by ligand‐mediated super‐assembly of the synthetic cells is further demonstrated. Such a robust and smart synthetic system that closely mimics the cellular activities of beta cells in response to glucose levels is promising for improving clinical outcomes in diabetes treatment.

Curcumin-Loading-Dependent Stability of PEGMEMA-Based Micelles Affects Endocytosis and Exocytosis in Colon Carcinoma Cells

Publisher: American Chemical Society (ACS)

Date: 22-01-2016

DOI: 10.1021/ACS.MOLPHARMACEUT.5B00820

Abstract: Polymeric micelles were formed from poly(poly(ethylene glycol) methyl ether methacrylate)-block-poly(styrene) (P(PEGMEMA)-b-PS) block copolymer of two different chain lengths. The micelles formed were approximately 16 and 46 nm in diameter and used to encapsulate curcumin. Upon loading of the curcumin into the micelles, their size increased to approximately 34 and 80 nm in diameter, respectively, with a loading efficiency of 58%. The unloaded micelles were not cytotoxic to human colon carcinoma cells, whereas only the smaller loaded micelles were cytotoxic after 72 h of exposure. The micelles were rapidly internalized by the cells within minutes of exposure, with the loaded micelles internalized to a greater extent owing to their enhanced stability compared to that of the unloaded micelles. The larger micelles were more rapidly internalized and exocytosed than the smaller micelles, demonstrating the effect of micelle size and drug loading on drug delivery and cytotoxicity.

Quantitative wear particle analysis for osteoarthritis assessment

Publisher: SAGE Publications

Date: 05-10-2017

DOI: 10.1177/0954411917735081

Abstract: Osteoarthritis is a degenerative joint disease that affects millions of people worldwide. The aims of this study were (1) to quantitatively characterise the boundary and surface features of wear particles present in the synovial fluid of patients, (2) to select key numerical parameters that describe distinctive particle features and enable osteoarthritis assessment and (3) to develop a model to assess osteoarthritis conditions using comprehensive wear debris information. Discriminant analysis was used to statistically group particles based on differences in their numerical parameters. The analysis methods agreed with the clinical osteoarthritis grades in 63%, 50% and 61% of particles for no osteoarthritis, mild osteoarthritis and severe osteoarthritis, respectively. This study has revealed particle features specific to different osteoarthritis grades and provided further understanding of the cartilage degradation process through wear particle analysis – the technique that has the potential to be developed as an objective and minimally invasive method for osteoarthritis diagnosis.

Sulfated polysaccharide-based scaffolds for orthopaedic tissue engineering

Publisher: Elsevier BV

Date: 09-2019

DOI: 10.1016/J.BIOMATERIALS.2019.05.025

Abstract: Given their native-like biological properties, high growth factor retention capacity and porous nature, sulfated-polysaccharide-based scaffolds hold great promise for a number of tissue engineering applications. Specifically, as they mimic important properties of tissues such as bone and cartilage they are ideal for orthopaedic tissue engineering. Their biomimicry properties encompass important cell-binding motifs, native-like mechanical properties, designated sites for bone mineralisation and strong growth factor binding and signaling capacity. Even so, scientists in the field have just recently begun to utilise them as building blocks for tissue engineering scaffolds. Most of these efforts have so far been directed towards in vitro studies, and for these reasons the clinical gap is still substantial. With this review paper, we have tried to highlight some of the important chemical, physical and biological features of sulfated-polysaccharides in relation to their chondrogenic and osteogenic inducing capacity. Additionally, their usage in various in vivo model systems is discussed. The clinical studies reviewed herein paint a promising picture heralding a brave new world for orthopaedic tissue engineering.

Development and performance of a biomimetic artificial perilymph forin vitrotesting of medical devices

Publisher: IOP Publishing

Date: 23-01-2019

DOI: 10.1088/1741-2552/AAF482

Abstract: Cochlear implants interface with the fluid in the cochlea called perilymph. The volume of this fluid present in human and animal model cochlea is prohibitively low for isolation for in vitro studies. Thus, there is a need for an artificial perilymph that reflects the complexity of this fluid in terms of competitive protein adsorption. This study established a biomimetic artificial perilymph (BAP) comprising serum albumin, immunoglobulin G, transferrin, inter-alpha-trypsin inhibitor, apolipoprotein A1 and complement C3 to represent the major components of human perilymph. Adsorption of the BAP components to platinum was analysed. It was established that this six component BAP provided competitive and complex adsorption behaviours consistent with biologically derived complex fluids. Additionally, adsorption of the BAP components to platinum cochlear electrodes resulted in a change in polarisation impedance consistent with that observed for the cochlear device in vivo. This study established a BAP fluid suitable for furthering the understanding of the implant environment for electroactive devices that interface with the biological environment.

Bioengineered human heparin with anticoagulant activity

Publisher: Elsevier BV

Date: 11-2016

DOI: 10.1016/J.YMBEN.2016.07.006

Abstract: Heparin is a carbohydrate anticoagulant used clinically to prevent thrombosis, however impurities can limit its efficacy. Here we report the biosynthesis of heparin-like heparan sulfate via the recombinant expression of human serglycin in human cells. The expressed serglycin was also decorated with chondroitin/dermatan sulfate chains and the relative abundance of these glycosaminoglycan chains changed under different concentrations of glucose in the culture medium. The recombinantly expressed serglycin produced with 25mM glucose present in the culture medium was found to possess anticoagulant activity one-seventh of that of porcine unfractionated heparin, demonstrating that bioengineered human heparin-like heparan sulfate may be a safe next-generation pharmaceutical heparin.

Glycosaminoglycan and Proteoglycan‐Based Biomaterials: Current Trends and Future Perspectives

Publisher: Wiley

Date: 06-12-2017

DOI: 10.1002/ADHM.201701042

Abstract: Proteoglycans and their glycosaminoglycans (GAG) are essential for life as they are responsible for orchestrating many essential functions in development and tissue homeostasis, including biophysical properties and roles in cell signaling and extracellular matrix assembly. In an attempt to capture these biological functions, a range of biomaterials are designed to incorporate off‐the‐shelf GAGs, typically isolated from animal sources, for tissue engineering, drug delivery, and regenerative medicine applications. All GAGs, with the exception of hyaluronan, are present in the body covalently coupled to the protein core of proteoglycans, yet the incorporation of proteoglycans into biomaterials remains relatively unexplored. Proteoglycan‐based biomaterials are more likely to recapitulate the unique, tissue‐specific GAG profiles and native GAG presentation in human tissues. The protein core offers additional biological functionality, including cell, growth factor, and extracellular matrix binding domains, as well as sites for protein immobilization chemistries. Finally, proteoglycans can be recombinantly expressed in mammalian cells and thus offer genetic manipulation and metabolic engineering opportunities for control over the protein and GAG structures and functions. This Progress Report summarizes current developments in GAG‐based biomaterials and presents emerging research and future opportunities for the development of biomaterials that incorporate GAGs presented in their native proteoglycan form.

The localisation of inflammatory cells and expression of associated proteoglycans in response to implanted chitosan

Publisher: Elsevier BV

Date: 02-2014

DOI: 10.1016/J.BIOMATERIALS.2013.10.068

Abstract: Implantation of a foreign material almost certainly results in the formation of a fibrous capsule around the implant however, mechanistic events leading to its formation are largely unexplored. Mast cells are an inflammatory cell type known to play a role in the response to material implants, through the release of pro-inflammatory proteases and cytokines from their α-granules following activation. This study examined the in vivo and in vitro response of mast cells to chitosan, through detection of markers known to be produced by mast cells or involved with the inflammatory response. Mast cells, identified as Leder stained positive cells, were shown to be present in response to material implants. Additionally, the mast cell receptor, c-kit, along with collagen, serglycin, perlecan and chondroitin sulphate were detected within the fibrous capsules, where distribution varied between material implants. In conjunction, rat mast cells (RBL-2H3) were shown to be activated following exposure to chitosan as indicated by the release of β-hexosaminidase. Proteoglycan and glycosaminoglycans produced by the cells showed similar expression and localisation when in contact with chitosan to when chemically activated. These data support the role that mast cells play in the inflammatory host response to chitosan implants, where mediators released from their α-granules impact on the formation of a fibrous capsule by supporting the production and organisation of collagen fibres.

RAP-modulated fluid processes: First passages and the stationary distribution

Publisher: Elsevier BV

Date: 07-2022

DOI: 10.1016/J.SPA.2022.03.013

Technical University Of Denmark

Location: Denmark

View Organisation

UNSW Australia

Location: Australia

View Organisation

UNSW Sydney

Location: Australia

View Organisation

ARC Future Fellowships - Grant ID: FT220100092

Start Date: 02-2023

End Date: 02-2027

Amount: $1,071,010.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP1097149

Start Date: 2010

End Date: 12-2013

Amount: $394,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE190100032

Start Date: 2019

End Date: 02-2021

Amount: $346,500.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP100100504

Start Date: 12-2010

End Date: 12-2015

Amount: $240,546.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140101056

Start Date: 03-2015

End Date: 02-2021

Amount: $360,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0776293

Start Date: 2008

End Date: 12-2012

Amount: $148,224.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP150104242

Start Date: 01-2015

End Date: 12-2021

Amount: $252,069.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP190101003

Start Date: 11-2020

End Date: 11-2023

Amount: $600,633.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140100109

Start Date: 06-2015

End Date: 07-2018

Amount: $290,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP100100037

Start Date: 06-2013

End Date: 09-2015

Amount: $230,000.00

Funder: Australian Research Council