Effective Delivery of Paclitaxel-Loaded Ferritin via Inverso CendR Peptide for Enhanced Cancer Therapy

The application of drug delivery systems based on ferritin nanocarrier has been developed as a potential strategy in cancer therapy. The limited permeability of ferritin remains a challenge for drug penetration into the deeper tumor tissues. CendR peptides have been reported to bear tumor-specific penetration by recognizing neuropilin (NRP-1) receptor that overexpressed on a wide range of cancer cells. Herein, we modified CendR peptide _L(RGERPPR), its retro-inverso peptide _D(RPPREGR), and inverso peptide _D(RGERPPR) on the outer surface of human H chain ferritin by sulfhydryl-maleimide coupling reaction. Approximately 45 paclitaxel (PTX) molecules could be loaded into each ferritin inner cavity by a thermal-triggered method at a specific ionic strength. The penetration ability of three peptide-modified ferritin constructs showed that _D(RGERPPR)-modified HFtn was able to be engulfed by A549 and MCF-7 tumor cells and spheroids at the highest level. Due to the dual-targeting effect of ferritin and modified peptides, the PTX-loaded nanocomposites could effectively enter the cells with high expression of TfR1 and NRP-1 receptors and enhanced the cytotoxicity against tumor cells. Remarkably, H-_D(RGE)-PTX displayed a superior tumor growth suppression efficacy in A549 tumor-bearing nude mice. The inverso CendR peptide-modified HFtn nanocarrier was first generated and could provide an effective dual-targeting platform for treatment of cancers.