ORCID Profile
0000-0002-0135-480X
Current Organisations
University of Leeds
,
University of York
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Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B911625G
Publisher: Elsevier BV
Date: 06-2006
DOI: 10.1016/J.BIOMATERIALS.2006.01.026
Abstract: The purpose of this study was to produce a well-characterised electrospun polystyrene scaffold which could be used routinely for three-dimensional (3D) cell culture experimentation. A linear relationship (p<0.01) between three principal process variables (applied voltage, working distance and polymer concentration) and fibre diameter was reliably established enabling a mathematical model to be developed to standardise the electrospinning process. Surface chemistry and bulk architecture were manipulated to increase wetting and handling characteristics, respectively. X-ray photoelectron spectroscopy (XPS) confirmed the presence of oxygen-containing groups after argon plasma treatment, resulting in a similar surface chemistry to treated tissue culture plastic. The bulk architecture of the scaffolds was characterised by scanning electron microscopy (SEM) to assess the alignment of both random and aligned electrospun fibres, which were calculated to be 0.15 and 0.66, respectively. This compared to 0.51 for collagen fibres associated with native tissue. Tensile strength and strain of approximately of 0.15 MPa and 2.5%, respectively, allowed the scaffolds to be routinely handled for tissue culture purposes. The efficiency of attachment of smooth muscle cells to electrospun scaffolds was assessed using a modified 3-[4,5-dimethyl(thiazol-2yl)-3,5-diphery] tetrazolium bromide assay and cell morphology was assessed by phalloidin-FITC staining of F-actin. Argon plasma treatment of electrospun polystyrene scaffold resulted in significantly increased cell attachment (p<0.05). The alignment factors of the actin filaments were 0.19 and 0.74 for the random and aligned scaffold respectively, compared to 0.51 for the native tissue. The data suggests that electrospinning of polystyrene generates 3D scaffolds which complement polystyrene used in 2D cell culture systems.
Publisher: Elsevier BV
Date: 05-2007
DOI: 10.1016/J.BIOMATERIALS.2007.01.032
Abstract: Although synthetic biomaterials have a wide range of promising applications in regenerative medicine and tissue engineering, there is limited insight into the basic materials properties that influence cellularisation events. The aim of this study was to investigate the influence of the physical properties of polyester films on the adherence and growth of normal human urothelial and urinary smooth muscle (SM) cells, as part of a programme for the development of potential biomaterials for bladder tissue engineering. Films of different thickness were produced by spin coating from solution. Cell attachment and proliferation were analysed and revealed a reproducible and significant growth advantage over the initial 7 days for both cell types on poly(lactide-co-glycolide) (PLGA) versus poly(epsilon-caprolactone) (PCL), and on thick versus thin films. In order to understand the basis of the variation in cell growth, the surface morphology, degradation behaviour and mechanical properties of the films were investigated. The pattern of cell attachment and growth was found to be unrelated to surface topography and no distinction in film degradation behaviour was found to account for differences in cell growth, except at late time points (14 days), where degradation of thin PLGA films became significant. By contrast, the flexural loss and storage moduli were found to be reduced in films composed of PLGA versus PCL, and also as film thickness increased, indicating that mechanical properties of biomaterials can influence cell growth. We conclude that elastic modulus is relevant to biology at the cellular scale and may also be influential at the tissue/organ level, and is a critical parameter to be considered during development of synthetic biomaterials for tissue engineering.
Publisher: Elsevier BV
Date: 03-2009
DOI: 10.1016/J.BIOMATERIALS.2008.11.033
Abstract: Previous work on 2D synthetic films showed growth of human bladder stromal cells was enhanced on materials with lower moduli that mimic the elastic properties of native tissue. This study developed 3D synthetic foam scaffolds for soft tissue engineering by emulsion freeze-drying. Foams of poly(lactide-co-glycolide) (PLGA) and poly(epsilon-caprolactone) (PCL) were extensively characterised using scanning electron microscopy, mercury porosimetry, dynamic mechanical analysis, degradation analysis, size exclusion chromatography and differential scanning calorimetry. Foams of 85-88% porosity and 35 microm pore diameter were selected for further study the storage modulus of PCL foams was around half that of PLGA (2 MPa vs 4 MPa) and closer to the reported value for native bladder tissue. Urinary tract stromal cells showed a 4.4 and 2.4-fold higher attachment and rate of growth, respectively, on PCL scaffolds, as assessed by a modified 3-[4,5-dimethyl(thiazol-2yl)-3,5-diphery] tetrazolium bromide assay. A greater contractile force was exerted by cells seeded in PLGA than on PCL scaffolds, raising the possibility that the reduced rate of proliferation of cells on PLGA scaffolds may reflect differentiation into a contractile phenotype. This study has generated PCL foam scaffolds with properties that may be pertinent to the tissue engineering of the bladder and other soft tissues.
Publisher: Wiley
Date: 22-02-2011
Abstract: Flexible, strong scaffolds were created by crosslinking PCL with 1,6-hexamethylenediisocyanate, using paraffin beads as a porogen. Particulate leaching generated homogeneous scaffolds with interconnected spherical pores of 5-200 µm. Subcutaneous implantation in rats for 3 months resulted in minimal scaffold resorption and a non-inflammatory regenerative host response, with complete infiltration by alternatively-activated CD68(+) macrophages. In addition, scaffolds were populated extensively along microfractures by a stromal matrix, which was highly vascularised and contained a subset of stromal cells that expressed the anti-inflammatory CD163 antigen. Such microfractures may be an important physical feature for directing stromal integration and vascularisation events.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Jennifer Southgate.