Development of Polydopamine-Coated Particles for the Delivery of Therapeutic Agents Post-Myocardial Infarction

Abstract

Successful delivery and maximal retention of therapeutic agents at the site of injury is important for cardiac repair post-myocardial infarction. Polydopamine (PDA) is considered a bioadhesive with excellent adhesion properties. This thesis aims to develop and test a PDA coating that can be applied to the surface of delivery particles so as to increase their adhesion strength and thus improve their retention at the site of infarction post-delivery. As a proof-of-principle, we investigated whether PDA coating on fluorescent beads confers a better retention rate at the site of delivery compared to non-coated beads. The first part of the study focused on the optimization of the PDA coating so as to finalize a deposition time for the coating process which will have the maximum adhesion strength. Once the PDA protocol with maximum adhesion strength was identified, PDA coating was performed on commercially available fluorescent beads. The viability of cultured macrophages and endothelial cells was not different when exposed to PDA-coated fluorescent beads compared to non-coated beads. In vivo, PDA-coated or non-coated beads were sprayed onto the surface of the mouse myocardium and their retention was evaluated at 3 hours and 1 day post-delivery. Fluorescence imaging results showed that the retention of PDA-coated beads on the myocardium was significantly greater than for non-coated beads at 1 day after application. These results suggest that PDA coating may be a strategy to improve the retention of carriers delivering therapeutic agents for the treatment of myocardial infarction, thus potentially improving therapeutic efficacy.