Targeted deoxycholic acid-loaded nanoliposomes enhance cell-associated uptake and modulate polarization-associated markers in THP-1-derived M2-like macrophages

Abstract

Tumor-associated macrophages (TAMs) frequently exhibit M2-like properties that support tumor progression. Deoxycholic acid (DCA), a secondary bile acid with amphiphilic membrane activity and context-dependent immunomodulatory effects, may influence macrophage phenotype. This study developed mannose-targeted DCA-loaded nanoliposomes and evaluated their physicochemical characteristics, cell-associated uptake, cytotoxicity, and effects on polarization-associated markers in THP-1-derived M2-like macrophages. Cellular uptake was assessed qualitatively by DiI fluorescence microscopy in two replicate experiments. Cytotoxicity was evaluated by MTT assay over 0.25-100 µM, and CD80/CD206 expression was assessed by flow cytometry after exposure to 10 or 20 µM DCA for 48 h. The targeted formulation had a mean hydrodynamic diameter of 155.1 ± 0.34 nm, a PDI of 0.28, a zeta potential of -12.8 ± 0.6 mV, spherical morphology, and an encapsulation efficiency of 82.94%. HPLC showed a DCA-associated peak at 6.215 min in the reference standard, disrupted DCA-loaded liposomes, and the unencapsulated fraction, whereas no corresponding peak was detected in the mobile-phase or blank-liposome controls. The formulation produced concentration-dependent cytotoxicity, with an estimated IC 50 of 13.47 µM. At 20 µM for 48 h, the percentage of CD206-positive cells changed from 76.8 ± 2.31% to 21.7 ± 1.98%, whereas the percentage of CD80-positive cells changed from 18.6 ± 1.72% to 68.3 ± 2.54%. Because 20 µM exceeded the estimated IC 50 , these observations may partly reflect selective cell loss. Flow-cytometric measurements were performed in triplicate (n = 3), but confirmation in independent biological experiments remains necessary. Additional viability-matched and functionally validated experiments are required.