A gelatin-based microgel was prepared by a simple method starting from gelatin and alginate. The microgel was composed of a soft gelatin-based core coated by a permeable membrane. Gelatin-based core was moderately crosslinked by a novel crosslinker 4-arm PEG succinimidyl glutarate (pentaerytheritol core) (sPEG-4A-GS(10 k)).