Gelatin-based porous silicon hydrogel composites for the controlled release of tramadol

•Porous silicon microparticles improve hydrogel swelling capabilities.•Drug dosage can be controlled by the amount ofmicroparticles and crosslinking nature.•Drug release mechanism of porous silicon-based gelatin hydrogels follows an anomalous behavior.•Porous silicon particles increase the elastic properties of gelatin hydrogel composites.