Drug loading/release and bioactivity research of a mesoporous bioactive glass/polymer scaffold

Abstract Mesoporous materials have attracted widespread attention in the field of drug delivery. Nevertheless, the weak interfacial interaction between them and drug molecules affects drug loading capacity and release kinetics. In this work, mesoporous bioactive glass (MBG) was functionalized via polydopamine to enhance the interfacial interaction with dexamethasone (DEX). Concretely, on the one hand, the amine groups of polydopamine could form hydrogen bonds with the hydroxyl groups of MBG. On the other hand, the catechol groups could form π-π bonds with the benzene rings of DEX molecules. Subsequently, DEX-loaded polydopamine-functionalized MBG (pMBG@DEX) was incorporated into polyglycolic acid/poly-1-lactic acid (PGPL) to construct a scaffold (PGPL/pMBG@DEX) via laser additive manufacturing process. The results indicated that the loadage of DEX increased by about 40% after polydopamine functionalization, from 1.28 to 1.75 μg/mg. More importantly, the burst effect was avoided. The enhanced intermolecular interaction between pMBG and DEX may be primarily responsible for this phenomenon, as it acts as a driving force to drug loading and a restraining force to drug release. PGPL/pMBG@DEX scaffold also exhibited significantly enhanced cell differentiation, mechanical properties and biomineralization activity.