Delivery of Corn-Derived Nanoparticles with Anticancer Activity to Tumor Tissues by Modification with Polyethylene Glycol for Cancer Therapy.

ABSTRACT

PURPOSE: We recently reported that intratumoral injection of corn-derived nanoparticles (cNPs) affords anticancer activity in tumor-bearing mice. To increase their applicability in cancer therapy, we examined the tissue distribution of cNPs after intravenous injection in mice, modified their surface with polyethylene glycol (PEG) to improve tumor delivery, and examined tissue distribution and anticancer activity of PEG-cNPs in tumor-bearing mice. METHODS: N-(Carbonyl-methoxypolyethyleneglycol2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-PEG) was added to cNPs by sonication to obtain PEG-cNPs, and the ratio of DSPE-PEG to cNPs was optimized by evaluating the modification efficiency. cNPs and PEG-cNPs were labeled with fluorescent dyes DiO or DiR, and their tissue distribution was subsequently examined after intravenous administration to mice. Finally, we determined the anticancer activity and toxicity of PEG-cNPs. RESULTS: No detectable fluorescence intensity was observed in mouse serum after intravenous DiR-cNP injection. DSPE-PEG was successfully modified into cNPs, and a PEGcNPs ratio of 50 was determined as optimal for preparing PEG-cNPs, based on their size and zeta potential. DiO-PEG-cNPs exhibited significantly higher serum concentrations and lower liver accumulation than DiO-cNPs. Moreover, DiR-PEG-cNPs accumulated in tumor tissues of colon26 tumor-bearing mice. Repeated intravenous PEG-cNP injections significantly retarded tumor growth, with no significant hepatotoxicity or nephrotoxicity. CONCLUSION: Overall, these results indicate that controlling the tissue distribution of cNPs via PEG modification on their surface can be a valuable strategy for developing intravenously injectable cNPs for cancer therapy.