Development of PLGA‐PEG‐COOH and Gelatin‐Based Microparticles Dual Delivery System and E‐Beam Sterilization Effects for Controlled Release of BMP‐2 and IGF‐1

Abstract

A poly(lactic‐co‐glycolic acid)‐poly(ethylene glycol)‐carboxyl (PLGA‐PEG‐COOH) and gelatin‐based microparticles (MPs) dual delivery system for release of bone morphogenetic protein‐2 (BMP‐2) and insulin‐like growth factor‐1 (IGF‐1) is developed. The delivery system is characterized based on its morphology, loading capacity, encapsulation efficiency, and release kinetics. The effects of electron beam (EB) sterilization on BMP‐2 and IGF‐1‐loaded MPs and their biological effects are examined. The synergistic effect of a controlled dual release of BMP‐2 and IGF‐1 on osteogenesis of human mesenchymal stem cells (MSCs) is evaluated. Encapsulation efficiency of growth factors into gelatin and PLGA‐PEG‐COOH MPs is in the range of 64.78% to 76.11%. E‐beam sterilized growth factor delivery systems are effective in significantly promoting osteogenesis of MSCs, although E‐beam sterilization decreases the bioactivity of growth factors in MPs by ≈22%. BMP‐2 release behavior from gelatin MPs/PEG hydrogel shows a faster release (52.7%) than that of IGF‐1 from the PLGA‐PEG‐COOH MPs/PEG hydrogel (27.3%). The results demonstrate that the gelatin and PLGA‐PEG‐COOH MPs‐based delivery system can realize temporal release of therapeutic biomolecules by incorporating different growth factors into distinct microparticles. EB sterilization is an accessible method for sterilizing growth factors‐loaded carriers, which can pave the way for implementing growth factor delivery in clinical applications.