Cells cell-free scaffolds

Figure 4.9 Mechanical stability of 3D biomimetic scaffolds during in vitro culture. Compressive mechanical properties of biomimetic scaffolds with and without cells measured under wet conditions, a-d) Representative stress-strain curves of 3D biomimetic scaffolds during 28 days of cell culture a) cell-seeded, b) cell-free scaffolds after 14 days of culture, c) cell-seeded, d) cell-free scaffolds after 28 days of culture, and e) cell-seeded scaffolds were able to maintain their mechanical properties, whereas the cell-free scaffolds showed significant decrease in compressive modulus after 28 days of culture due to the polymer hydrolytic degradation. ( ) indicates significant decrease for the same type of scaffold at different time points, p <0.05. Cell-seeded scaffolds showed higher compressive moduli at all the time points compared with cell-free scaffolds due to the reinforced extracellular matrix secreted by cells during the cell culture. Reproduced with permission from M. Deng, S.G. Kumbar, L.S. Nair, A.L. Weikel, H.R. Allcock and C.T. Laurencin, Advanced Functional Materials, 2011,21, 2641. 2011, Wiley-VCH [3]...

Lyons, F. G., Al-Munajjed, A. A., Kieran, S. M., Toner, M. E., Murphy, . M., Duffy, G. P., and O Brien, F. J. (2010). The healing of bony defects by cell-free collagen-based scaffolds compared to stem cell-seeded tissue engineered constructs. Biomaterials 31, 9232-9245. 

Fig. 4 Immunohistochemistry results for cell-free CCP and TE-CCP scaffolds at 4 and 8 weeks, (a) Staining for the immunomodulatory and tissue remodeling (M2 phenotype) marker CD163 at 4 weeks demonstrated active M2 macrophage activity in the scaffold substance, particularly at sites of new bone formation and the host-scaffold interface in cell-free scaffolds. These cells were less evident by 8 weeks, suggesting an advanced stage of the remodeling process, (b) In the TE scaffolds, M2 phenotype macrophages were evident at both 4 and 8 weeks predominantly at the periphery of the scaffold, especially in the fibrous/inflammatory capsule seen previously on histological examination, (c) The proinflammatoiy (CCR7) marker demonstrated little Ml macrophage cell activity in unseeded scaffolds at either 4 or 8 weeks, (d) There was marked population of these cells at the periphery of TE scaffolds at both 4 and 8 weeks. Reproduced with permission from Lyons et al. [86]...

Cell delivery cell cultured in vitro into a scaffold before implantation > Direct implantation of the scaffold (cell-free tissue engineering)... 

Fagerholm P, et al. Stable comeal regeneration four years after implantation of a cell-free recombinant human collagen scaffold. Biomaterials 2014 35(8) 2420—7. 

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