Incorporation of protein-loaded microspheres into chitosan-polycaprolactone scaffolds for controlled release

► Growth factor is entrapped into chitosan microspheres for local release. ► Microsphere-embedded scaffolds can control the release without severe burst. ► Scaffolds made of chitosan-based copolymer have desirable strength in wet state. ► Scaffolds administrate the release over an extended period longer than four weeks. ► Pore parameters of scaffolds instead of microspheres regulate release rates.