Development and in vitro evaluation of ursolic acid-loaded poly(lactic-co-glycolic acid) nanoparticles in cholangiocarcinoma

Abstract

Cholangiocarcinoma (CCA), an epithelial biliary tract malignancy, is a significant health concern in the Greater Mekong Subregion, particularly in northeastern Thailand. Prior to the development of advanced stages, CCA is typically asymptomatic, thereby limiting treatment options and chemotherapeutic effectiveness. Ursolic acid (UA), a triterpenoid derived from plants, was previously discovered to inhibit CCA cell growth through induction of apoptosis. Nevertheless, the therapeutic effectiveness of UA is limited by its poor solubility in water and low bioavailability; therefore, dimethyl sulfoxide (DMSO) is utilized as a solvent to treat UA with CCA cells. Enhancing cellular uptake and reducing toxicity, the utilization of polymeric nanoparticles (NPs) proves beneficial. In this study, UA-loaded PLGA nanoparticles (UA-PLGA NPs) were synthesized using nanoprecipitation and characterized through in silico formation analysis, average particle size, surface functional groups and ζ-potential measurements, electron microscopic imaging, drug loading efficiency and drug release studies, stability, hemo- and biocompatibility, cytotoxicity and cellular uptake assays. Molecular dynamics simulations validated the loading of UA into PLGA via hydrogen bonding. The synthesized UA-PLGA NPs had a spherical shape with an average size of 240 nm, a negative ζ-potential, good stability, great hemo- and bio-compatibility and an encapsulation efficiency of 98%. The NPs exhibited a characteristic of a simple diffusion-controlled Fickian process, as predicted by the Peppas–Sahlin drug release kinetic model. UA-PLGA NPs exhibited cytotoxic effects on KKU-213A and KKU-055 CCA cells even when dispersed in media without organic solvent, i.e., DMSO, highlighting the ability of PLGA NPs to overcome the poor water solubility of UA. Rhodamine 6G (R6G) was loaded into PLGA NPs using the same approach as UA-PLGA NPs, demonstrating effective delivery of the dye into CCA cells. These findings suggest that UA-PLGA NPs showed promise as a potential phytochemical delivery system for CCA treatment.