Controlled release triggered by enzymatic degradation for DDS using alginate hydrogel microparticles

Abstract

In this paper, we succeeded in releasing 20 nm fluorescent silica particles, which is approximately the same size as Adeno-Associated Virus (AAV), by a composite structure of calcium alginate and collagen. Alginate microparticles encapsulating fluorescent silica were prepared using a centrifuge based microfluidic device, which was mixed with collagen and solidified to produce a composite hydrogel structure. Alginate lyase was applied to the complete hydrogel to dissolve only alginate microparticles, resulting in release of, fluorescent silica nanoparticles by permeating collagen. We also confirmed the effect on cells in this release system by performing live/dead assay. Almost all cells continued to live for 3 days after the releasing nanoparticles, meaning that there was no cytotoxicity to cells. In the future, we will encapsulate AAV in alginate microparticles to apply our method to a practical DDS system for gene therapy.