Parenteral Berberine vs Cisplatin- Loaded Lipid Nanoparticles – Development, Characterisation, Comparative Safety Profiling and Cytotoxicity in Cholangiocarcinoma Cell Models

Introduction: Cholangiocarcinoma (CCA) is an aggressive and heterogeneous malignancy of the biliary tract with a poor prognosis. Berberine can be a therapeutic option with low toxicity, but its delivery remains challenging. Encapsulation in lipid nanoparticles offers a promising biocompatible strategy to improve the delivery and safety of berberine. Purpose: This study aimed to develop, characterize berberine-loaded nanostructured lipid carriers (N-Ber) and evaluate their cytotoxicity in CCA cell models in comparison to a standard chemotherapeutic, cisplatin, in both free and nanoparticle-loaded form (N-Cis). The in vitro biocompatibility for potential parenteral delivery of the nanocarriers was a secondary goal of the work. Methods: Nanoparticles were prepared by solvent evaporation with Precirol 5 ATO and oleic acid as lipids and Tween 20 as a stabilizer and were characterized by DLS, morphology, encapsulation efficiency, and in vitro drug release at physiological (pH 7.4) and tumor-mimicking (pH 5.5) conditions. Cytotoxicity was evaluated in three CCA cell lines (TFK-1, EGI-1, and HuCCT1) using the MTT assay, while endothelial cells (Ea.hy926) and the hemolysis test in human erythrocytes were employed to evaluate safety. Results: N-Ber and N-Cis displayed mean sizes 159.5 nm and 146.7 nm, respectively, negative surface charge (− 27.95 mV and − 50.75 mV), and high encapsulation efficiencies (berberine: 88.8%; cisplatin: 95.8%). Both nanoformulations showed significantly altered dissolution profiles compared to the free drugs. Berberine showed potent cytotoxicity against all CCA cell lines (IC 5 0 0.4– 5.2 μM), comparable or superior to cisplatin (IC 5 0 ≈ 10 μM) and these effects were preserved after nanoencapsulation. In contrast, N-Ber exhibited low toxicity towards endothelial cells and no relevant hemolytic activity (< 5% hemolysis) at therapeutic concentrations, while N-Cis induced marked hemolysis at all tested doses. Discussion: N-Ber combines strong cytotoxicity in CCA cells with a favorable biocompatibility compared to N-Cis. The promising in vitro data warrant further in vivo evaluation. Keywords: cholangiocarcinoma, berberine, cisplatin, nanostructured lipid carriers, cytotoxicity