Green silver nanoparticles curcumin conjugate induced photodynamic therapy of lung cancer and lung cancer stem cells

Lung cancer remains a dreaded disease globally due to its high mortality rates. 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 study examines a bioformulated photoactive curcumin-silver nanoparticle-polymer conjugate (Cum-PEG-BpAgNPs) and free curcumin (Cum) in eradicating lung cancer via photodynamic therapy (PDT). The LCSCs characterization confirmed the presence of CD133+ and CD44+ LCSCs subpopulations. The Cum-PEG-BpAgNPs-mediated PDT induced substantial cytotoxicity in lung cancer cells and LCSCs compared to curcumin-mediated PDT. It also induced elevated ROS production, resulting in damage to the mitochondria and apoptosis. The apoptotic mechanism was triggered through the upregulation of apoptotic proteins, including caspase-3 and p53, and the downregulation of Bcl-2 anti-apoptotic proteins. The nanoconjugate (Cum-PEG-BpAgNPs) thus shows superior lung cancer PDT efficacy over curcumin, suggesting potential for resistant cancer treatment.