Silica-collagen hybrid and composite materials as advanced dermal substitutes.

DESIMONE, M.F; C HÉLARY; G MOSSER; I RIETVELD; I BATAILLE; A MEDDAHI-PELLÉ; C AIME; J LIVAGE; MM GIRAUD-GUILLE; T CORADIN

Strasbourg

Conferencia; Second International Conference on Multifunctional, Hybrid and Nanomaterials; 2011

One of the main challenges in the area of skin tissue engineering is to design cellularized devices that can deliver therapeutic products to the host favouring wound healing. In fact, transplantation of dermal substitute scaffolds colonized by fibroblast has shown several advantages over acellularized materials. The first objective of the present work was improve the mechanical properties of collagen gel by adding two different silica species, under conditions compatible with the simultaneous immobilization of human dermal fibroblast. Cell viability estimated by MTT, SEM and TEM observations, combined with mechanical testing, DSC measurements and ICP-AES were performed. Herein, the combination of collagen concentrations higher than in classical hydrogels together with the addition of silica species has successfully improve the mechanical and thermal properties of the materials and represents a better environment to afford cell proliferation. The second objective of this work is related to the behaviour of these materials in the contact with living tissues. Collagen gels with a final concentration of 0.8 and 3 mg ml-1 together with the silica-collagen hybrids and Si12-collagen nanocomposites materials were implanted subcutaneously within rat abdomen. After 8 days, histological analysis revealed a complete colonization of low concentrated collagen and silicified collagen gels, by the host cells. The CD68 immunolabeling revealed the presence of inflammatory cells within all the materials with low collagen concentration. The amount of macrophages seems to be slightly lower in Si12-collagen and silica-collagen gels. Moreover, endothelial cells were detected by RECA-1 within these gels and in some cases organized cells in open tubular structures were observed. It is possible to conclude, through in vitro studies that silicified collagen efficiently slow down collagen hydrogel contraction while preserving fibroblast viability and activity. In vivo studies demonstrated the absence of a major immediate post-transplant inflammatory response denoting the biocompatibility of the materials