ORCID Profile
0000-0002-6619-5328
Current Organisations
University of Queensland Australian Institute for Bioengineering and Nanotechnology
,
UNSW Sydney
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Publisher: MDPI AG
Date: 30-12-2022
Abstract: Cancer stem cells (CSCs) are primarily responsible for tumour drug resistance and metastasis thus, targeting CSCs can be a promising approach to stop cancer recurrence. However, CSCs are small in numbers and readily differentiate into matured cancer cells, making the study of their biological features, including therapeutic targets, difficult. The use of three-dimensional (3D) culture systems to enrich CSCs has some limitations, including low sphere forming efficiency, enzymatic digestion that may damage surface proteins, and more importantly no means to sustain the stem properties. A responsive 3D polymer extracellular matrix (ECM) system coated with RGD was used to enrich CSCs, sustain stemness and avoid enzymatic dissociation. RGD was used as a targeting motif and a ligand to bind integrin receptors. We found that the system was able to increase sphere forming efficiency, promote the growth of spheric cells, and maintain stemness-associated properties compared to the current 3D culture. We showed that continuous culture for three generations of colon tumour spheroid led to the stem marker CD24 gradually increasing. Furthermore, the new system could enhance the cancer cell sphere forming ability for the difficult triple negative breast cancer cells, MBA-MD-231. The key stem gene expression for colon cancer also increased with the new system. Further studies indicated that the concentration of RGD, especially at high doses, could inhibit stemness. Taken together, our data demonstrate that our RGD-based ECM system can facilitate the enrichment of CSCs and now allow for the investigation of new therapeutic approaches for colorectal cancer or other cancers.
Publisher: American Chemical Society (ACS)
Date: 23-08-2021
Publisher: Wiley
Date: 18-07-2022
Abstract: Nanostructured polymeric materials play important roles in many advanced applications, however, controlling the morphologies of polymeric thermosets remains a challenge. This work uses multi‐arm macroCTAs to mediate polymerization‐induced microphase separation (PIMS) and prepare nanostructured materials via photoinduced 3D printing. The characteristic length scale of microphase‐separated domains is determined by the macroCTA arm length, while nanoscale morphologies are controlled by the macroCTA architecture. Specifically, using 2‐ and 4‐ arm macroCTAs provides materials with different morphologies compared to analogous monofunctional linear macroCTAs at similar compositions. The mechanical properties of these nanostructured thermosets can also be tuned while maintaining the desired morphologies. Using multi‐arm macroCTAs can thus broaden the scope of accessible nanostructures for extended applications, including the fabrication of actuators and potential drug delivery devices.
Publisher: American Chemical Society (ACS)
Date: 08-01-2020
DOI: 10.1021/ACS.BIOMAC.9B01637
Abstract: Conventional self-assembly methods of block copolymers in cosolvents (i.e., usually water and organic solvents) has yet to produce a pure and monodisperse population of nanocubes. The requirement to assemble a nanocube is for the second block to have a high molecular weight. However, such high molecular weight block copolymers usually result in the formation of kinetically trapped nanostructures even with the addition of organic cosolvents. Here, we demonstrate the rapid production of well-defined polymer nanocubes directly in water by utilizing the thermoresponsive nature of the second block (with 263 monomer units), in which the block copolymer was fully water-soluble below its lower critical solution temperature (LCST) and would produce a pure population of nanocubes when heated above this temperature. Incorporating a pH-responsive monomer in the second block allowed us to control the size of the nanocubes in water with pH and the LCST of the block copolymer. We then used the temperature and pH responsiveness to create an adaptive system that changes morphology when using a unique fuel. This fuel (H
Publisher: American Chemical Society (ACS)
Date: 22-08-2022
Publisher: Wiley
Date: 06-12-2022
Abstract: Currently, there are no straightforward methods to 3D print materials with nanoscale control over morphological and functional properties. Here, a novel approach for the fabrication of materials with controlled nanoscale morphologies using a rapid and commercially available Digital Light Processing 3D printing technique is demonstrated. This process exploits reversible deactivation radical polymerization to control the in‐situ‐polymerization‐induced microphase separation of 3D printing resins, which provides materials with complex architectures controllable from the macro‐ to nanoscale, resulting in the preparation of materials with enhanced mechanical properties. This method does not require specialized equipment or process conditions and thus represents an important development in the production of advanced materials via additive manufacturing.
Publisher: Wiley
Date: 31-01-2022
Abstract: Anisotropic Janus (“snowman”) nanoparticles with a single protrusion are currently made via the solvent swelling‐induced method. Here, we demonstrate without the aid of toxic solvents a generally applicable method for the formation of anisotropic polymer nanoparticles directly in water by controlling polymer mobility through tuning its glass transition temperature ( T g ). Spherical structures, formed immediately after the emulsion polymerization, transformed into uniform tadpoles (with head diameter ≈60 nm and tail length ≈130 nm) through the protrusion of a single cylindrical tail when cooled to a temperature above the T g of the polymer. Cooling the spheres to below the T g produced kinetically trapped kettlebell structures that could be freeze‐dried and rehydrated without any structural change. These unique kettlebells could transform into uniform tadpoles by heating above the T g , representing a triggered and on‐demand structural reorganization.
Publisher: Springer Science and Business Media LLC
Date: 22-06-2022
DOI: 10.1038/S41467-022-31095-9
Abstract: Although 3D printing allows the macroscopic structure of objects to be easily controlled, controlling the nanostructure of 3D printed materials has rarely been reported. Herein, we report an efficient and versatile process for fabricating 3D printed materials with controlled nanoscale structural features. This approach uses resins containing macromolecular chain transfer agents (macroCTAs) which microphase separate during the photoinduced 3D printing process to form nanostructured materials. By varying the chain length of the macroCTA, we demonstrate a high level of control over the microphase separation behavior, resulting in materials with controllable nanoscale sizes and morphologies. Importantly, the bulk mechanical properties of 3D printed objects are correlated with their morphologies transitioning from discrete globular to interpenetrating domains results in a marked improvement in mechanical performance, which is ascribed to the increased interfacial interaction between soft and hard domains. Overall, the findings of this work enable the simplified production of materials with tightly controllable nanostructures for broad potential applications.
Publisher: American Chemical Society (ACS)
Date: 26-03-2020
Publisher: Wiley
Date: 22-09-2022
Abstract: The development of advanced solid‐state energy‐storage devices is contingent upon finding new ways to produce and manufacture scalable, high‐modulus solid‐state electrolytes that can simultaneously provide high ionic conductivity and robust mechanical integrity. In this work, an efficient one‐step process to manufacture solid polymer electrolytes composed of nanoscale ion‐conducting channels embedded in a rigid crosslinked polymer matrix via Digital Light Processing 3D printing is reported. A visible‐light‐mediated polymerization‐induced microphase‐separation approach is utilized, which produces materials with two chemically independent nanoscale domains with highly tunable nanoarchitectures. By producing materials containing a poly(ethylene oxide) domain swelled with an ionic liquid, robust solid polymer electrolytes with outstanding room‐temperature (22 °C) shear modulus ( G ’ 10 8 Pa) and ionic conductivities up to σ = 3 × 10 −4 S cm −1 are achieved. The nanostructured 3D‐printed electrolytes are fabricated into a custom geometry and employed in a symmetric carbon supercapacitor, demonstrating the scalability of the fabrication and the functionality of the electrolyte. Critically, these high‐performance materials are manufactured on demand using inexpensive and commercially available 3D printers, which allows the facile modular design of solid polymer electrolytes with custom geometries.
Publisher: Wiley
Date: 19-06-2023
Abstract: In this study, the fabrication of 3D‐printed polymer materials with controlled phase separation using polymerization induced microphase separation (PIMS) via photoinduced 3D printing is demonstrated. While many parameters affecting the nanostructuration in PIMS processes are extensively investigated, the influence of the chain transfer agent (CTA) end group, i.e., Z‐group, of macromolecular chain transfer agent (macroCTA) remains unclear as previous research has exclusively employed trithiocarbonate as the CTA end group. Herein, the effect of macroCTAs containing four different Z‐groups on the formation of nanostructure of 3D printed materials is explored. The results show that the different Z‐groups lead to distinct network formation and phase separation behaviors between the resins, influencing both the 3D printing process and the resulting material properties. Specifically, less reactive macroCTAs toward acrylic radical addition, such as O ‐alkyl xanthate and N ‐alkyl‐ N ‐aryl dithiocarbamate, result in translucent and brittle materials with macrophase separation morphology. In contrast, more reactive macroCTAs such as S ‐alkyl trithiocarbonate and 4‐chloro‐3,5‐dimethylpyrazo dithiocarbamate produce transparent and rigid materials with nano‐scale morphology. Findings of this study provide a novel approach to manipulate the nanostructure and properties of 3D printed PIMS materials, which can have important implications for materials science and engineering.
Publisher: Wiley
Date: 18-09-2023
Abstract: The majority of materials 3D printed using vat photopolymerization techniques are prepared by uncontrolled polymerization methods and cannot be easily modified to introduce additional functionality these materials can be considered as effectively “dead” materials. Fortunately, a suite of photocontrolled reversible–deactivation radical polymerization (photoRDRP) techniques is recently implemented in 3D printing. In addition to their fast polymerization rate and oxygen tolerance, the high livingness imparted by photoRDRP methods is beginning to disrupt the field of 3D printing by providing access to materials with advanced properties, including on‐demand editing of surface and bulk properties, self‐healing, and control over nanostructuration and mechanical properties. This mini‐review analyzes the development of photoRDRP techniques in the field of photoinduced 3D printing with an emphasis on the advanced and highly tailorable materials possible through these techniques.
Publisher: American Chemical Society (ACS)
Date: 02-09-2019
DOI: 10.1021/ACS.BIOMAC.9B01088
Abstract: Polymer nanostructures can be designed with tailored properties and functions by varying their shape, chemical compositions, and surface functionality. The poor stability of these soft materials in solvent other than water can be overcome by introducing cross-links. However, cross-linking complex morphologies remains a challenge. Here, by using the temperature-directed morphology transformation method, we show that the symmetric (nanoworm) and asymmetric (tadpole) nanostructure cores can be UV-cross-linked through the coupling of styrene and
Location: Australia
No related grants have been discovered for Valentin BOBRIN.