Self-Assembly and Sustained Release Properties of Drug Loaded PEC Microcapsules

In order to explore high efficient utilization of the polysaccharides biomaterials, the cellulose sulfate-chitosan hydrochloride-sodium tripolyphosphate (NaCS-CHC-STPP) microcapsules were used as core/template, while aqueous 1% (g/mL) NaCS and 0.5% (g/mL) CHC as respective polyelectrolyte self-assembly solutions, the microcapsules with four layers structure (PEC4) were fabricated via layer-by-layer self-assembly method. The influences of the self-assembled layer structure on the sustained release properties of the obtained microcapsules were investigated. The membrane structure of PEC microcapsule was characterized by digital single lens reflex camera, scanning electron microscope and Zeta potential analysis, and the drug release performance of drug-loaded microcapsule was measured and analyzed in simulated colonic fluid. The results indicate that the microcapsules (1≤n≤3) obtained by self-assembly method have the round morphology and denser internal structure compared with the template (n=0). Zeta potential analysis show that it represents a regular variation trend with the alternating assembly of NaCS and CHC. Fourier transform infrared spectroscopy analysis confirm that the chemical reaction occurrs between CHC and NaCS. The in vitro drug release studies manifest that with the increase of self-assembled PEC layer structure (1≤n≤2), the sustained drug release performance of the drug-loaded microcapsules is significantly improved; the structure of the microcapsules becomes wrinkled and rough with micro pores. These results could provide a theoretical reference for designing and developing of sustained drug release delivery systems. © 2021, Editorial Board of Polymer Materials Science & Engineering. All right reserved.