Yeast-Originated drug Carriers: Comprehensive study from preparation to functional evaluation

Abstract

Yeast glucan particles (YGPs), natural drug delivery carriers derived from yeast cells, exhibit negative charges, enabling electrostatic drug binding. Their β-glucan-rich surface demonstrates substantial biological activity and recognition by macrophage Dectin-1 receptors, promising for development. Nevertheless, as a natural material, the pretreatment process for yeast microcapsules has yet to undergo systematic exploration, resulting in diverse process parameters. This study aims to optimize the fabrication process of yeast microcapsules, focusing on enhancing their cavity capacity and electrostatic adsorption abilities, thereby improving their loading capacity for positively charged drugs. Our objective is to provide a standardized protocol for subsequent applications, facilitating the advancement of yeast-based drug delivery systems. YGPs were prepared via an alkali-acid-organic solvent method, employing various process parameters. The encapsulation efficiency and loading capacity of YGPs for target drugs (positively charged Berberine) served as primary indices. By analyzing the changes in Zeta potential under different process conditions, the optimal acid-alkali treatment temperatures were determined to be 70 °C and 60 °C, respectively, with an optimal treatment duration of 1 h. Processed YGPs can effectively shield their active ingredient (Berberine) from gastrointestinal degradation and delay its release. The optimally processed yeast microcapsules exhibited a Zeta potential of −10.8 mV, a β-glucan content of (73.32 ± 3.18) %, and substantial internal drug-carrying capacity without inducing hemolysis. Furthermore, the ability of these microcapsules to be specifically recognized and phagocytosed by macrophages via the Dectin-1 receptor was confirmed, underscoring their potential for macrophage-targeted in vivo applications. This study provides both experimental insights and a foundation for the investigation of oral drug delivery carriers.