Estudo da esterilização e da calcificação in vitro de membranas de fibroina de seda para a aplicação como biomaterial / Study of sterization and in vitro calcification of silk fibroin membranes for biomaterial application

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility, biodegradability and minimal inflammatory reactions. Sterilization is a fundamental step in biomaterials processing, and it must not alter in a negative way the functionality of medical devices. On the applicability of fibroin as a biomaterial, recent studies verified that fibroin can be used as a scaffold for mimicking biomineralization, promoting the growing of hydroxyapatite crystals. The aim of this study was to analyze the influence of different sterilization methods on physical, mechanical and biological characteristics of dense and porous silk fibroin membranes, and also to study the application of the fibroin membranes as biomaterials, through in vitro calcification studies. Dense and porous fibroin membranes were sterilized by ultraviolet radiation, 70% ethanol, autoclave, ethylene oxide and gamma radiation, and were analyzed by SEM, FTIR-ATR, XRD, mechanical and cytotoxicity tests. For in vitro calcification experiments, the fibroin membranes were soaked in SBF for seven days, and characterized by SEM and EDS. The results for sterilization indicated that none of the methods caused degradation or formation of cytotoxic substances. The methods that used organic solvent, and increase of humidity and/or temperature (70% ethanol, autoclave and ethylene oxide) increased the crystallinity of the dense membranes, and stabilized the porous membranes, characteristics that may be utilized when a slow in vivo degradation is desired, depending on the application. The calcification experiments indicated that silk fibroin may induce calcification, by forming calcium phosphate deposits with a Ca/P ratio similar to that of hydroxyapatite and its precursors. Porous membranes presented higher tendency to calcify, when compared to dense membranes, due to its surface roughness and high porosity, indicating that porous silk fibroin membranes may be considered for application in bone regeneration

ASSUNTO(S)

calcification calcificação sterilization esterilização

Documentos Relacionados