International journal of nanomedicine
PVP-Stabilized Ag@SiO2 Nanocarriers for Usnic Acid: Physicochemical Characterization and Exploratory in vitro Anticancer, Antimicrobial, and Immunomodulatory Activity
By Pyrczak-Felczykowska A, Kowalska A, Adamska E and 9 others.
Abstract
Background
Usnic acid (UA) is a lichen-derived metabolite with recognized anticancer, anti-inflammatory, and antibacterial properties; however, its clinical application is limited by poor aqueous solubility and dose-dependent toxicity. This study aimed to develop a multifunctional nanosystem to improve UA aqueous dispersibility and efficacy against breast cancer cells in vitro.
Methods
A nanosystem consisting of a silver core-silica shell coated with polyvinylpyrrolidone (PVP) and conjugated UA (Ag@SiO2/PVP/UA) was synthesized and characterized regarding morphology, physicochemical properties, colloidal stability, drug loading, and release behavior. Antiproliferative activity was evaluated using breast cancer cells (MCF-7 and MDA-MB-231). Cytotoxicity was assessed using the MTT viability assay, reactive oxygen species (ROS) production by flow cytometry, and metabolic alterations through LC-MS/MS-based metabolomic analysis. Antimicrobial activity against Gram-positive and Gram-negative bacteria was expressed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Immunomodulatory properties were assessed in human peripheral blood mononuclear cells (PBMCs) using ELISA, while fibroblast migration was analyzed using an in vitro wound healing assay.