RESUMO
The final goal of the present study was the development of a 3-D chitosan dressing that would shorten the healing time of skin wounds by stimulating migration, invasion, and proliferation of the relevant cutaneous resident cells. Three-dimensional chitosan nanofibrillar scaffolds produced by electrospinning were compared with evaporated films and freeze-dried sponges for their biological properties. The nanofibrillar structure strongly improved cell adhesion and proliferation in vitro. When implanted in mice, the nanofibrillar scaffold was colonized by mesenchymal cells and blood vessels. Accumulation of collagen fibrils was also observed. In contrast, sponges induced a foreign body granuloma. When used as a dressing covering full-thickness skin wounds in mice, chitosan nanofibrils induced a faster regeneration of both the epidermis and dermis compartments. Altogether our data illustrate the critical importance of the nanofibrillar structure of chitosan devices for their full biocompatibility and demonstrate the significant beneficial effect of chitosan as a wound-healing biomaterial.
Assuntos
Materiais Biocompatíveis/química , Quitosana , Microfibrilas/metabolismo , Nanofibras/química , Pele/efeitos dos fármacos , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Cicatrização/efeitos dos fármacos , Animais , Bandagens , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quitosana/química , Quitosana/metabolismo , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Granuloma , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Microfibrilas/química , Microfibrilas/ultraestrutura , Microscopia Eletrônica de Varredura , Nanofibras/ultraestrutura , Neovascularização Fisiológica/efeitos dos fármacos , Pele/crescimento & desenvolvimento , Cicatrização/fisiologiaRESUMO
For many years, chitosan and its derivatives have been considered to be promising biomaterials for tissue engineering and repair. However, information regarding their biological effect on cell phenotype is usually limited to evaluation of cell proliferation and survival, overlooking proteomic and transcriptomic analysis. This is largely related to the lack of efficient and quantitative procedures for protein and nucleic acid purification from cells cultured on, or inside, chitosan scaffold. Here we describe an ultracentrifugation procedure enabling the simultaneous and quantitative recovery of high quality RNA, DNA and proteins from cells growing in close contact of biomaterial matrices containing chitosan.