Optoresponsive Pheophorbide-Silver based organometallic nanomaterials for high efficacy multimodal theranostics in Melanoma

Opto/light-responsive materials are a choice in modern-days due to their vital role in non-invasive cancer therapies and diagnostics. We propose a novel, near-infrared (NIR) light absorbing organometallic nanosystem for the multimodal theranostics against melanoma. More specifically, a fluorescent organic molecule, Pheophorbide-a (Ph-a) was loaded on the NIR light absorbing silver nanoparticles (AgNPs). The resulting formulation was referred to as PhAg NPs. The organic entity serves as a chemotherapeutic and imaging agent whereas the metallic system aid in the photothermal ablation of cancer cells. The PhAg NPs upon characterisation indicated a strong absorption in the NIR region and exhibited a robust photothermal profile upon exposure to the NIR light. The anti-cancer efficacy studies of the PhAg NPs were conducted in melanoma (in-vitro & in-vivo) models to understand the chemo/photothermal therapeutic effect. Our experimental results demonstrated a synergistic cytotoxic and tumor reduction effect due to the photothermal and chemotherapeutic potential of the PhAg NPs. Further photoacoustic (PA) and fluorescent imaging indicated that the PhAg NPs could serve as efficient non-invasive imaging probes due to their inherent NIR fluorescence properties. Overall, the PhAg NPs served as a unique organometallic system which had demonstrated its efficacy as a multimodal theranostic agent. Further in-depth understanding of the proposed organometallic nanoparticles (PhAg NPs) can be beneficial in their clinical translation against melanoma or similar tumors.