| 초록 |
There have been emerging efforts towards the development of integrated cancer therapeutic platforms consisting of photodynamic therapy (PDT) and photothermal therapy (PTT) involving visible/NIR light-absorbing metal nanostructures (as photothermal transducers) and organic photosensitizer (PS) molecules (as reactive oxygen species (ROS) generators). However, there are several challenges that need to be addressed for the full utilization of this hybrid nanostructure-based approach. These include the energy transfer between PS and the nanostructures, and mismatch between their absorption wavelengths, the requirement of lower operation temperature or non-thermal treatment, and the toxicity of the nanostructures and their complex conjugation chemistry. Further, there has been no effort towards exploring the ROS generation capability of NIR-active plasmonic nanostrucutures in combination with their inherent hyperthermic effect for potential continuous wave–NIR laser cancer phototherapy without the need for additional organic PS molecules. Here, we introduce a strategy for the controlled synthesis of plasmonic core-petal nanostructures (CPNs) with highly branched morphologies. The fine nanostructural engineering of CPNs was facilitated by gold chloride-induced oxidative disassembly of biopolymer polydopamine corona around spherical Au nanoparticles and successive anisotropic growth of Au nanopetals. We show that CPNs can act as multifunctional nanoreactors that induce protrusion-dependent, controllable photodynamic and photothermal dual therapeutic effects and ROS generation. NIR laser-activated CPNs can be used to induce the effective destruction of cancer cells via the combination of benign plasmonic hyperthermia (~42 °C) and ROS-mediated oxidative intracellular damage. It was also shown that CPNs exhibit very strong surface-enhanced Raman scattering (SERS) signals, and this allows for post-mortem probing of ROS-mediated oxidative structural modifications of DNA, which mutations could be responsible for the apoptotic fate of cancer cells. Synthetic access towards such biocompatible, and aesthetic, but highly effective nanotherapeutic platforms have great potential for future clinical applications. |
