LCST-mediated phase separation strategy for preparation of poly(amino alcohol ethers) microparticle-gelatin hydrogel composites

Abstract

In this study, we report a facile two-step strategy to aid the preparation of microparticle-hydrogel composites. By leveraging amine-epoxy “click” chemistry, in combination with lower critical solution temperature (LCST)-mediated phase separation phenomenon of the in situ formed poly(amino alcohol ethers) (TP) prepolymer in water, as well as integration of gelatin, a series of poly(amino alcohol ethers) microparticle-gelatin hydrogel (TGP) composites can be readily prepared through the simultaneous preparation of bulk hydrogel network and microparticles. Our strategy allows easy tuning of microstructures and mechanics, as well as degradation properties of the obtained TGP composites through varying the volume ratio of TP prepolymer solution and gelatin solution. Moreover, applicability of such TGP composites to modulate cell response was demonstrated in vitro with NIH3T3 fibroblasts and chicken primary neurons. Furthermore, with hydrophobic domains in microparticles, such TGP composites are also feasible to tailor anti-inflammatory effect via curcumin encapsulation. Altogether, this study provides new insights into the design strategy to achieve microparticle-hydrogel composites to warrant consideration for drug delivery and tissue engineering applications.