| 1. |
- Deng, C, et al.
(författare)
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A Collagen-Chitosan Hydrogel for Endothelial Differentiation and Angiogenesis
- 2010
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Ingår i: TISSUE ENGINEERING PART A. - : Mary Ann Liebert. - 1937-3341 .- 1937-335X. ; 16:10, s. 3099-3109
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Tidskriftsartikel (refereegranskat)abstract
- Cell therapy for the treatment of cardiovascular disease has been hindered by low cell engraftment, poor survival, and inadequate phenotype and function. In this study, we added chitosan to a previously developed injectable collagen matrix, with the aim of improving its properties for cell therapy and neovascularization. Different ratios of collagen and chitosan were mixed and chemically crosslinked to produce hydrogels. Swell and degradation assays showed that chitosan improved the stability of the collagen hydrogel. In culture, endothelial cells formed significantly more vascular-like structures on collagen-chitosan than collagen-only matrix. While the differentiation of circulating progenitor cells to CD31(+) cells was equal on all matrices, vascular endothelial-cadherin expression was increased on the collagen-chitosan matrix, suggesting greater maturation of the endothelial cells. In addition, the collagen-chitosan matrix supported a significantly greater number of CD133(+) progenitor cells than the collagen-only matrix. In vivo, subcutaneously implanted collagen-chitosan matrices stimulated greater vascular growth and recruited more von Willebrand factor (vWF(+)) and CXCR4(+) endothelial/angiogenic cells than the collagen-only matrix. These results indicate that the addition of chitosan can improve the physical properties of collagen matrices, and enhance their ability to support endothelial cells and angiogenesis for use in cardiovascular tissue engineering applications.
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| 2. |
- Kuraitis, D, et al.
(författare)
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A STROMAL CELL-DERIVED FACTOR-1 RELEASING MATRIX ENHANCES THE PROGENITOR CELL RESPONSE AND BLOOD VESSEL GROWTH IN ISCHAEMIC SKELETAL MUSCLE
- 2011
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Ingår i: European Cells & Materials. - : European Cells andamp; Materials Ltd. - 1473-2262. ; 22, s. 109-123
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Tidskriftsartikel (refereegranskat)abstract
- Although many regenerative cell therapies are being developed to replace or regenerate ischaemic muscle, the lack of vasculature and poor persistence of the therapeutic cells represent major limiting factors to successful tissue restoration. In response to ischaemia, stromal cell-derived factor-1 (SDF-1) is up-regulated by the affected tissue to stimulate stem cell-mediated regenerative responses. Therefore, we encapsulated SDF-1 into alginate microspheres and further incorporated these into an injectable collagen-based matrix in order to improve local delivery. Microsphere-matrix impregnation reduced the time for matrix thermogelation, and also increased the viscosity reached. This double-incorporation prolonged the release of SDF-1, which maintained adhesive and migratory bioactivity, attributed to chemotaxis in response to SDF-1. In vivo, treatment of ischaemic hindlimb muscle with microsphere-matrix led to increased mobilisation of bone marrow-derived progenitor cells, and also improved recruitment of angiogenic cells expressing the SDF-1 receptor (CXCR4) from bone marrow and local tissues. Both matrix and SDF-1-releasing matrix were successful at restoring perfusion, but SDF-1 treatment appeared to play an earlier role, as evidenced by arterioles that are phenotypically older and by increased angiogenic cytokine production, stimulating the generation of a qualitative microenvironment for a rapid and therefore more efficient regeneration. These results support the release of implanted SDF-1 as a promising method for enhancing progenitor cell responses and restoring perfusion to ischaemic tissues via neovascularisation.
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