Biodistribution of indocyanine green-loaded nanoparticles with surface modifications of PEG and folic acid

To establish the biodistribution profile of the PLGA nanoparticles with dual surface modifications of PEG and folic acid (FA) in mice xenografted with MDA-MB-231 human breast cancer cells with high expression of folate receptor (FR); and to illustrate that the modified nanoparticles can target the loaded indocyanine green (ICG) to the tumor with high FR expression. ICG-loaded nanoparticles were prepared with PLGA (non-modified nanoparticles, NM-NP) or mPEG-PLGA and FA-PLGA (dual modified nanoparticles, DM-NP). Biodistribution of the ICG-loaded nanoparticles (1.25 mg/kg) after i.v. injection was investigated on athymic mice transplanted with MDA-MB-231 tumor. ICG concentration in plasma from the DM-NP group was significantly (p < 0.05) higher than the NM-NP group from 90 min to the end of the study (12 h). After 4 h, the drug concentration in the tumor tissue from the DM-NP started to be significantly (p < 0.05) higher than the NM-NP until 12 h. Compared to the NM-NP, the DM-NP increased the AUC0–12 h in plasma by 245% and the AUC0–12 h in tumor by 194%, while decreased the AUC0–12 h in liver by 13%. The accumulation of DM-NP into the tumor was significantly higher than NM-NP due to the long circulation and FR-mediated uptake.