SiO2 entrapment of animal cells - Part I - mechanical features of sol-gel SiO2 coatings

Natural silk fibers show valuable changes in elastic modulus, E, and failur e stress, sigma(f), upon treatment with an air flux of gaseous Si-alkoxides bearing a thin sol-gel layer of SiO2 on the fiber surface. These mechanica l features are studied here as a function of the composition of gaseous flu x and reaction time. Owing to the different behavior between original and t reated fibers submitted to loading-unloading cycles, the maximum increase i n E (about 50%) and sigma(f) (about 30%) are discussed in terms of intermol ecular surface interactions of -O-Si-O- bridging groups and protein macromo lecules. As an extension of this system, composed of a thin sol-gel SiO2 la yer (0.05-0.1 mu m) on protein surfaces, the mechanical improvement of coll agen + cell deposits upon deposition of sol-gel SiO2 is suggested. (C) 1999 Kluwer Academic Publishers.