Porous and bioactive gentamicin sulfate-loaded gelatin-siloxane hybrids were successfully synthesized by using a combined sol-gel processing, post-gelation soaking, and freeze-drying process. A bone-like apatite layer was able to form in the Ca2 + -containing porous gentamicin-loaded hybrids upon soaking in a simulated body fluid (SBF) up to 1 day. The drug release of gentamicin sulfate was with a burst, followed by an almost constant release up to 7 days. And the rate of release in acidic medium was lower than that in the neutral and basic media.