Biodegradable Gold Nanovesicles with an Ultrastrong Plasmonic Coupling Effect for Photoacoustic Imaging and Photothermal Therapy

TLDR

Hierarchical assembly of gold nanoparticles enables tuning of localized surface plasmon resonance into the near‑infrared, enhancing photothermal therapy. The authors present biodegradable plasmonic gold nanovesicles as a theranostic platform for photoacoustic imaging and photothermal therapy. Dense packing of GNPs via a disulfide‑terminated PEG‑b‑PCL block‑copolymer induces ultrastrong plasmonic coupling, producing strong NIR absorption and a 37 % photothermal conversion efficiency for simultaneous PA imaging and PTT. The nanovesicles achieve effective PA imaging and PTT with improved clearance, and illustrate that assembling diverse nanocrystals into vesicles creates versatile multifunctional biodegradable platforms for biomedical use.

Abstract

Abstract The hierarchical assembly of gold nanoparticles (GNPs) allows the localized surface plasmon resonance peaks to be engineered to the near‐infrared (NIR) region for enhanced photothermal therapy (PTT). Herein we report a novel theranostic platform based on biodegradable plasmonic gold nanovesicles for photoacoustic (PA) imaging and PTT. The disulfide bond at the terminus of a PEG‐ b ‐PCL block‐copolymer graft enables dense packing of GNPs during the assembly process and induces ultrastrong plasmonic coupling between adjacent GNPs. The strong NIR absorption induced by plasmon coupling and very high photothermal conversion efficiency ( η =37 %) enable simultaneous thermal/PA imaging and enhanced PTT efficacy with improved clearance of the dissociated particles after the completion of PTT. The assembly of various nanocrystals with tailored optical, magnetic, and electronic properties into vesicle architectures opens new possibilities for the construction of multifunctional biodegradable platforms for biomedical applications.