Structural Characterization, Dynamic Behaviour, and Targeted Biodistribution of Calcium-Loaded Liposome Based on Soybean Lecithin and Cholesterol

Liposome formulated from soybean lecithin and cholesterol is a versatile nanocarrier platform with physicochemical behavior tightly dictated by phospholipid–cholesterol ratio. Therefore, this study aimed to prepare calcium-loaded liposome across a series of lecithin to cholesterol compositions and systematically evaluated the structural attributes and in vivo biodistribution. Liposome was produced through thin-film hydration and comprehensively characterized with respect to hydrodynamic diameter, zeta potential, polydispersity index (PDI), and colloidal stability. Quantitative biodistribution profiling of calcium was examined using high-resolution X-ray fluorescence (XRF) spectroscopy. Among the evaluated formulations, the 70:30 (lecithin:cholesterol) ratio had the most favorable colloidal features, producing nanoscale vesicles with a mean diameter of 198.5 nm, a high absolute zeta potential (−58 mV), and a narrow size distribution (PDI < 0.3). In vivo analysis found a distinct biodistribution pattern, characterized by significantly elevated calcium accumulation in pancreas (75.2%) and kidneys (62.4%), with substantially lower deposition in liver (26.9%) and heart (13.9%). Collectively, the results showed that the 70:30 formulation conferred an enhanced organ-directed delivery of calcium, a phenomenon possibly governed by intrinsic organ microenvironments and differential vascular permeability compared to classical enhanced permeability and retention (EPR) mechanisms. The data showed the translational potential of this liposomal system and opportunities to further refine organ selectivity through rational surface engineering, including ligand-based targeting strategies.