Lipid insertion enables targeted functionalization of paclitaxel-loaded erythrocyte membrane nanosystem by tumor-penetrating bispecific recombinant protein.

BACKGROUND: There is currently much interest in cancer cell targeting and tumor penetrating for research and therapeutic purposes. PURPOSE: To improve targeting delivery of antitumor drugs to gastric cancer, in this study, a tumor-targeting biocompatible drug delivery system derived from erythrocyte membrane for delivering paclitaxel (PTX) was constructed. METHODS: Erythrocyte membrane of human red blood cells (RBCs) were used for preparing of erythrocyte membrane-derived vesicles. 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(maleimide[polyethylene glycol]-3400) (DSPE-PEG-MAL), a phospholipid derivative, was used to insert tumor-targeting molecular into erythrocyte membrane-derived vesicles. A lipid insertion method was used to functionalize these vesicles without the need for direct chemical conjugation. Furthermore, a tumor-penetrating bispecific recombinant protein named anti-EGFR-iRGD was used for the first time in this work to enable nanosystem to target and penetrate efficiently into the tumor site. RESULTS: Paclitaxel (PTX)-loaded anti-EGFR-iRGD-modified erythrocyte membrane nano-system (anti-EGFR-iRGD-RBCm-PTX, abbreviated to PRP) were manufactured. PRP was spheroid, uniformly size, about 171.7±4.7 nm in average, could be stable in vitro for 8 days, and released PTX in a biphasic pattern. PRP showed comparable cytotoxicity toward human gastric cancer cells in vitro. In vivo studies showed that, PRP accumulated in tumor site within 2 h of administration, lasted longer than 48 h, and the tumor volume was reduced 61% by PRP treatment in Balb/c nude mice, without causing severe side effects. CONCLUSION: PRP has potential applications in cancer treatment and as an adjunct for other anticancer strategies.

Gambogic acid-loaded PEG-PCL nanoparticles act as an effective antitumor agent against gastric cancer.

Poor water solubility and side effects hampered the clinical application of gambogic acid (GA) in cancer therapy. Accordingly, GA-loaded polyethylene glycol-poly(ɛ-caprolactone) (PEG-PCL) nanoparticles (GA-NPs) were developed and administered peritumorally to evaluate their antitumor activity. The particle size, polydispersity index, encapsulation efficiency and loading capacity of GA-NPs were 143.78 ± 0.054 nm, 0.179 ± 0.004, 81.3 ± 2.5% and 14.8 ± 0.6%, respectively. In addition, GA-NPs showed excellent stability, good biocompatibility and sustained release profile. Endocytosis studies in vitro demonstrated that the GA-NPs were effectively taken up by tumor cells in a time-dependent manner. In vivo real-time imaging showed that the nanoparticles effectively accumulated within the tumor tissue after peritumoral administration. The cytotoxicity study revealed that the GA-NPs effectively inhibited the proliferation of gastric cancer cells. In vivo antitumor therapy with peritumoral injection of GA-NPs exhibited superior antitumor activity compared with free GA. Moreover, no toxicity was detected in any treatment group. Histological studies confirmed a lower cell density and a higher number of apoptotic cells in the GA-NPs group compared with the free GA group. Furthermore, the expression level of the cysteine proteases 3 precursor (pro-caspase3), a crucial component of cellular apoptotic pathways, was efficiently reduced in mice treated with GA-NPs. In conclusion, the GA-NPs system provided an efficient drug delivery platform for chemotherapy.