Development of BSA gel/Pectin/Chitosan polyelectrolyte complex microcapsules for Berberine delivery and evaluation of their inhibitory effect on Cutibacterium acnes

The aim of this work was to develop a novel fully natural drug delivery system for the treatment of acne, based on core-shell microcapsules that contain Berberine (Brb). The two main objectives of the work were: a) the synthesis and the characterization of complex microcapsules (ms), ms encapsulating Berberine (ms-Brb), and b) in vitro evaluation of the release of Brb, of the cytotoxicity on normal skin cells and of the antimicrobial effect on Cutibacterium acnes (formerly Propionibacterium acnes) (C. acnes). For a), bovine serum albumin (BSA) gel-core microcapsules with alternating multilayer shells of calcium cross-linked Pectin (P) hydrogel and the polyelectrolyte complex formed by P and Chitosan (Chi) (BSA gel/P/Chi/P) were synthesized. The BSA gel-core microcapsules were obtained using a sacrificial CaCO3 template method, while the multilayer shell was formed through a technique consisting in the layer-by-layer (Lbl) deposition of polyelectrolyte complex formed by P and Chi. Brb was encapsulated into the resulting microcapsules, by a process of diffusion from solution. The structure characterization of ms/ms-Brb was performed by FTIR and UV–Vis spectroscopy, X-ray diffraction, confocal laser scanning microscopy, and scanning electron microscopy. The in vitro assessment of ms/ms-Brb cytotoxicity on skin cells was performed using keratinocyte (HaCaT) cell line. Results of physicochemical analyses confirm the successful encapsulation of Brb in ms, and the in vitro biological study recommends ms-Brb as a candidate for future in vivo research targeting anti-acne treatment.