Microfluidic immobilization of polyglycerin-b-poly(ε-caprolactone) polymeric micelles in uniform zwitterionic hydrogel microparticles for molecular network-mediated drug release

This study introduces a flexible and straightforward method for immobilization of polymeric micelles in monodisperse suspensions of hydrogel microparticles. Hydrogel particles loaded with polyglycerin- b -poly( ε -caprolactone) micelles were prepared using a capillary-based microfluidic method. For this, a uniform water-in-oil emulsion was generated in a microfluidic device. The aqueous dispersion drops contain polymeric micelles, monomers, and photo-initiators. Then, the emulsion drops were photo-polymerized to transfer them to hydrogel particles. The hydrogel phase was made of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) that has an enhanced biocompatibility due to the phosphorylcholine moiety in the backbone. Finally, we have demonstrated that the microfluidic approach is indeed useful for physically immobilizing polymeric micelles in between PMPC hydrogel meshes, which provides a means to regulate the release behavior of active ingredients encapsulated in the polymeric micelles.