Photopolymerized hydrogel composites from poly(ethylene glycol) and hydroxyapatite for controlled protein delivery in vitro

The incorporation of hard particles into soft hydrogels can improve the mechanical properties and provide necessary bioactivity to the hydrogels for desired biomedical applications. Hydrogel composites containing hydroxyapatite (HA) are promising materials for orthopedic applications. In this study, injectable poly(ethylene glycol) (PEG) hydrogel precursor solutions containing HA particles and model protein bovine serum albumin (BSA) were synthesized in situ by photopolymerization. In vitro BSA release properties from the hydrogel composites containing various amounts of HA were investigated and discussed. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to investigate the interaction between HA and the hydrogel network and the morphology of the hydrogel composites. It is found that PEG hydrogel composites containing HA sustained the release of BSA for at least 5 days and the presence of HA slowed down BSA release. Photopolymerized hydrogel composites containing HA may find potential use as a drug delivery matrix for orthopedic tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013