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 nanosystem (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.