Facile preparation of Au- and BODIPY-grafted lipid nanoparticles for synergized photothermal therapy

Gold nanoparticles with large size exhibit preferable properties for photothermal therapy (PTT). However, the prolonged tissue retention and slow elimination of gold nanoparticles limit their therapeutic applications. Previously, gold nanoclusters carrying lipid nanoparticles (Au-LNPs) have been reported after simply mixing Au³⁺ with preformed diethylenetriaminepentaacetic acid lipid nanoparticles to solve this contradiction. Au-LNPs demonstrated enhanced photothermal effects in comparison to neat gold nanoparticles. To further improve the photothermal activity, we introduced the organic photothermal agent boron dipyrromethene (BODIPY) to Au-LNPs for synergistic PTT. Au- and BODIPY-grafted LNPs (AB-LNPs) were formed by simply mixing Au-LNPs with BODIPY. The BODIPY could be associated stably to Au-LNPs, and the release of BODIPY from AB-LNPs could be accelerated by laser irradiation. AB-LNPs are scalable and showed excellent photothermal effects. AB-LNPs showed enhanced cellular uptake efficiency compared to free BODIPY in 4T1 breast cancer cells. Under laser irradiation, AB-LNPs exhibited synergistic photothermal effects with significantly reduced dosage compared to monotherapy (treatments with Au-LNPs or free BODIPY alone). This study thus provides a facile and adaptive strategy for the development of a scalable and safe high-performance nanoplatform for synergistic PTT in the treatment of cancer and other diseases.