Near-infrared nanoparticles based on indocyanine green-conjugated albumin: a versatile platform for imaging-guided synergistic tumor chemo-phototherapy with temperature-responsive drug release

BACKGROUND: The aim of this study was to develop a multifunctional theranostic agent based on BSA nanoparticles (NPs), which loaded artemisinin (ART) and co-conjugated with indocyanine green (ICG) and arginine-glycine-aspartic acid (RGD) peptide (RGD-indocyanine green-Bovine Serum Albumin-artemisinin [IBA] NPs). MATERIALS AND METHODS: The physicochemical parameters of RGD-IBA NPs were character-ized in terms of the particle size, zeta potential, morphology, entrapment efficiency, drug loading, in vitro release behavior, photothermal and photodynamic effect, and in vitro anticancer ability. In vivo fluorescence and thermal imaging as well as antitumor studies were also evaluated. RESULTS: The tumor chemotherapeutic effects of ART and the ability of fluorescence imaging, hyperthermia generation and reactive oxygen species production of ICG and tumor-targeting RGD were integrated to achieve RGD-IBA NPs for imaging-guided tumor-targeted chemotherapy/photothermal/photodynamic therapy (chemo-phototherapy). The RGD-IBA NPs showed enhanced physiological stability and photo-stability compared with free ART and ICG. In addition, they were temperature-responsive; their sizes increased with increasing temperature between 25°C and 55°C, thereby leading to drug release upon the irradiation with near infrared (NIR) laser. In vivo fluorescence images of tumor-bearing mice showed that the RGD-IBA NPs could highly and passively reach the targeted tumor region with maximum accumulation at 24 hours post-intravenous injection. The in vitro and in vivo results demonstrated that the RGD-IBA NPs not only have good biocompatibility, but also are highly efficient tumor synergistic chemo-phototherapeutic agents. CONCLUSION: Through this study, it was found that RGD-IBA NPs could potentially be a very promising tumor theranostic agent.