Sol-gel preparation and in vitro deposition of apatite on porous gelatin-siloxane hybrids

Ca(II) containing porous hybrids of gelatin and 3-(glycidoxypropyl)trimethoxysilane (GPSM) were prepared using a sol-gel process, post-gelation soaking, and freeze-drying. The porosity and pore size of the hybrids could be well controlled by the freezing temperature and the pH value of the soaking solution. The pore characteristics were related to the structure change during the soaking treatment. A second soaking of the porous hybrids introduced a binary-pore distribution. The rate of biodegradation in a trishydroxymethylaminomethane (Tris) buffer solution decreased with an increased GPSM content. A bone-like apatite layer was able to form in the Ca(II) containing porous gelatin-siloxane hybrids upon soaking in a stimulated body fluid (Kokubo recipe). These hybrid materials are proposed to find application as novel bioactive and biodegradable scaffolds in bone tissue engineering.