Selective Cellular Uptake and Cytotoxicity of Curcumin-encapsulated SPC and HSPC Liposome Nanoparticles on Human Bladder Cancer Cells

Background: Curcumin is a main bioactive constituent of turmeric (Curcuma longa L.) with pleiotropic health beneficial effects. However, poor bioavailability is the major barrier to the efficient pharmacological effects of curcumin in humans. Aims: The present study aimed to develop liposome formulations based on soybean phosphatidylcholine (SPC) and hydrogenated SPC (HSPC) to enhance the bioavailability of curcumin in bladder cancer cells. Methods: Curcumin was encapsulated in HSPC and SPC liposome nanoparticles using the solvent evaporation method. Physical properties, encapsulation efficiency (%), stability, and in vitro drug release of the prepared liposome formulations have been evaluated. The cellular uptake and cytotoxicity of curcumin-encapsulated nanoliposomes on bladder carcinoma HTB9 cell line and normal fibroblast L929 cell line were studied. DNA fragmentation, apoptosis, and genotoxicity assessments have been carried out to determine the molecular mechanisms underlying the cytotoxic effects of liposomal curcumin formulations on bladder cancer cells. Results: The results indicated that curcumin could be efficiently encapsulated in the HSPC and SPC liposome formulations. The liposomal curcumin formulations have shown shelf-life stability for 14 weeks at 4°C. The accelerated stability testing showed that curcumin encapsulated in nanoliposomes was significantly (p < 0.001) more stable than free curcumin at various pH degrees ranging from alkaline to acidic pH. The in vitro drug release study showed curcumin to be sustainably released from the liposome nanoparticles. Of note, SPC and HSPC nanoliposome formulations significantly increased the cellular uptake and cytotoxicity of curcumin on bladder cancer HTB9 cells. Mechanistically, liposomal curcumin was found to exert a selective inhibitory effect on the viability of cancer cells by inducing apoptosis and DNA damage. Conclusion: In conclusion, SPC and HSPC liposome nanoparticles can significantly increase the stability and bioavailability of curcumin, which are important for improving its pharmacological effect.