Experimental and computational understanding of pulsatile release mechanism from biodegradable core-shell microparticles

Next-generation therapeutics require advanced drug delivery platforms with precise control over morphology and release kinetics. A recently developed microfabrication technique enables fabrication of a new class of injectable microparticles with a hollow core-shell structure that displays pulsatile release kinetics, providing such capabilities. Here, we study this technology and the resulting core-shell microstructures. We demonstrated that pulsatile release is governed by a sudden increase in porosity of the polymeric matrix, leading to the formation of a porous path connecting the core to the environment. Moreover, the release kinetics within the range studied remained primarily independent of the particle geometry but highly dependent on its composition. A qualitative technique was developed to study the pattern of pH evolution in the particles. A computational model successfully modeled deformations, indicating sudden expansion of the particle before onset of release. Results of this study contribute to the understanding and design of advanced drug delivery systems.

Automated summary

This study explores a new microfabrication technique for the fabrication of injectable microparticles with a hollow core-shell structure and pulsatile release kinetics. The sudden increase in porosity of the polymeric matrix leads to the formation of a porous path connecting the core to the environment, enabling pulsatile release. The release kinetics of the microparticles were found to be primarily independent of particle geometry but highly dependent on composition. A qualitative technique was developed to study the pH pattern within the particles, and a computational model successfully simulated the particle deformations before release.