Design and evaluation of multi-core raspberry-like platinum nanoparticles for enhanced photothermal treatment

While gold-based nanoparticles are now commonly used in nanomedicine due to their stability and high plasmonic resonance, platinum nanoparticles are recently emerging as promising candidates for enhancing radiotherapy sensitivity due to their high atomic number. Here, we demonstrate that platinum-based nanomaterials with a multi-core structure also possess efficient near-infrared photothermal properties, despite platinum’s maximum absorption being primarily in the ultraviolet region. The photothermal efficacy of these platinum multi-core raspberry-like nanoparticles is compared with single-core ultra-small platinum nanoseeds, within glioblastoma cancer spheroids, showcasing the potential of platinum nanocore aggregation for photothermal therapy in cancer treatment. Additionally, we used a microfabrication technique for high-throughput growth of spheroids in microwells to evaluate photothermal treatment on glioblastoma spheroids. Finally, X-ray absorption spectroscopy was conducted to analyze the stability and behavior of both nanoparticles in the cellular environment, indicating their excellent biostability. Moreover, even after laser application, none of the nanoparticles degraded but instead underwent reshaping into a more crystalline structure.