Microfluidics assisted fabrication of microspheres by poly(2–hydroxyethyl methacrylate)-block-poly(l-histidine) hybrid materials and their utilization as potential drug encapsulants

Abstract

A new series of synthetic polymer bioconjugate hybrid materials consisting of poly(2-hydroxyethyl meth- acrylate)(p(HEMA))as a synthetic polymer block and poly(L-histidine) (p(His)) as a polypeptide block were syn- thesized by combining atom transfer radical polymerization of HEMA with ring opening polymerization of benzyl- N-carboxy-L-histidine anhydride. The resulting biocompat- ible p(HEMA)25-b-p(His)n (n = 15, 25, 35, and 45) hybrid polymers were investigated for their use as pH-sensitive drug delivery system. Highly uniform microspheres were fabricated by using the microfluidics assisted self-assembly of these block polymers and utilized them as carriers for a chemotherapeutic agent doxorubicin and a beta-lactam antibiotic ampicillin for the evaluation of the drug-loading and release behaviors according to pH, demonstrating the release is sensitive to pH. The capability of the new p(HEMA)-b-p(His) hybrid materials to self-assemble in microenvironments and to effectively encapsulate drug molecules serves as suitable carriers for the delivery of drug molecules with varying physiochemical properties.