Development of highly stable ICG-polymeric nanoparticles with ultra-high entrapment efficiency using supercritical...

Indocyanine green (ICG), a water-soluble near-infrared (NIR) photosensitizer, has been enormously regarded in tumor diagnosis and phototherapy. Although tremendous progress in establishing the nanocarrier-based delivery systems has been explored, several limitations of low ICG encapsulation and sophisticated fabrication process remain significant challenges in producing nanoplatforms, limiting the theranostic outcomes of ICG. According to the unique advantages of the supercritical antisolvent (SAS) process and solution casting method, a novel combination approach to obtain the ICG-loaded nanoparticles (ICG-PLO NPs) is demonstrated, in which SAS assisted-ICG nanoparticles (ICG NPs) are coated with polypeptide poly-l-ornithine (PLO) using solution casting approach. This unique nanoplatform with ultra-high drug encapsulation efficiency remarkably improved the aqueous and photothermal stability of ICG. Notably, the coating of PLO could improve the internalization level in cells and anticancer effect in vivo, comprehensively augmenting the cancer phototherapy effect of ICG. Together, the findings of novel particle formation by integrated strategy would certainly broaden the applications of supercritical fluid (SCF) technology, potentiating the design of nano-formulations of ICG for clinical translation.