Abstract
Lung cancer remains a dreaded disease globally due to its high mortality rates. New cases of lung cancer are estimated at 1.8 million a year, with about 1.6 million deaths. Conventional treatment regimens are inefficient due to their failure to eradicate lung cancer stem cells (LCSCs). LCSCs are noted to self-renew, cause relapse, strengthen metastasis, preserve tumorigenicity, and are very resistant to treatment. This shows the need for a novel treatment modality that can target lung cancer and its stem cells. In this study, a photoactive curcumin-silver nanoparticle-polymer conjugate (Cum-PEG-BpAgNPs) was developed to enhance lung cancer photodynamic therapy (PDT). Lung cancer cells and LCSCs were treated with Cum-PEG-BpAgNPs followed by light irradiation at 470 nm. Post-analytical assays including 3-[4,5-dimethylthiazole-2yl]-2,5-diphenyl tetrazolium bromide, lactate dehydrogenase, adenosine triphosphate, ROS by DCFH-DA, annexin V-FITC/PI cell death studies, and morphological analysis were performed. The characterization analysis confirmed the bio-formulation of Cum-PEG-BpAgNPs conjugate. The LCSCs characterization indicated the presence of LCSCs in the isolated cell population. The biochemical assays post-PDT revealed substantial cytotoxicity when lower concentrations of Cum-PEG-BpAgNPs were used. The IC50 value of the conjugate was noted at 4.014 μg mL-1 and 2.373 μg mL-1 for lung cancer cells and LCSCs, respectively. An elevated ROS production was induced, leading to apoptosis post-PDT. Therefore, Cum-PEG-BpAgNPs could be used in the mediation PDT to eliminate lung cancer cells effectively.