Effects of Precursor and Cross-linking Parameters on the Properties of Dextran-Allyl Isocyanate-Ethylamine/Poly(ethylene glycol diacrylate) Biodegradable Hydrogels and Their Release of Ovalbumin

Abstract

In this paper, we studied the effects of molecular weight of poly(ethylene glycol diacrylate) (PEGDA) precursor, the degree of substitution (DS) of both allyl isocyanate (AI) and amine groups in dextran-based precursor (Dex-AE), and photoinitiator concentration on Dex-AE/PEGDA hydrogel formation and its ovalbumin (OVA) release. FT-IR spectra showed chemical bond interaction between amine and urethane groups of the hydrogel carriers with OVA. The increase in PEGDA molecular weight led to a faster OVA release because of a more open gel network structure. The study on the DS of AI in Dex-AE precursor showed that an increase in AI did not result in a prominent gel network structure difference. However, the urethane groups in Dex-AE precursor showed some interactions with OVA and, thus, resulted in a slower release rate. The incorporation of amine group into Dex-AE precursor did not affect the gel network structure, but reduced the OVA release rate, and the level of reduction increased with an increasing amine group substitution into the Dex-AE precursor. This reduction could be attributed to the interaction between the amine groups in the gel carrier and OVA. An increase in the photoinitiator concentration showed no effect on the gel network structure or OVA release.