Application of liposomal nanoparticles of berberine in photodynamic therapy of A549 lung cancer spheroids

Application of liposomes is a critical strategy in drug delivery and increase cellular uptake of drugs having low water solubility. Berberine (BBR) is a bioactive compound found in several plants, including Goldenseal, Barberry, and Oregon grape. It has garnered attention for its various health benefits, particularly in metabolic health and antimicrobial activity. However, one of the challenges associated with BBR is its water solubility. Moreover, BBR has photosensitizing potential via absorbance of light and generation of free radicals. Hence, to improve water solubility and bioavailability, one of the important strategies employed is using lipid-based carriers to enhance solubility. In this study we employed liposomes to deliver BBR in A549 lung cancer spheroid cells to enhance photodynamic therapy efficacies. Results from the EDS and UV-Vis spectroscopy revealed that the BBR had been loaded onto liposomes, with three peaks appearing between 250 and 450 nm. Morphology of Lipo@BBR nanocomplex was in wavy crest shape and the size was 56.99 ± 3.74 nm in SEM and TEM analysis, respectively. FTIR data illustrated that Lipo@BBR has four significant peaks at 1250, 1459, 1736, and 2907 cm^-1. DLS data showed that Lipo@BBR has a negative surface charge with a -10.7 Zeta Potential (mV). Additionally, based on Zetasizer measurements, the size of Lipo@BBR complex was 82.7 ± 6.5. Cytotoxicity assay investigation with MTT assay presented that IC₅₀ of Lipo@BBR in PDT was 10 ± 0.5 μg/mL that led to a volume reduction of the A549 spheroids after five sessions of PDT fractionation (total light dose was set at 25 J/cm²). qPCR and immunofluorescence results demonstrated that Lipo@BBR increases the BAX/BCL2 ratio in A549 spheroid cells, hence improving PDT efficiency. In conclusion, our results illustrated that safe dose of Lipo@BBR (10 ± 0.5 μg/mL) in PDT fractionation protocol can be one of the strategies to suppress the tumor volume and cell death proliferation. Authors recommend using Lipo@BBR nanocomplex in PDT fractionation as well as more in vivo investigation is warranted.