Phycocyanin-based nanocarrier as a new nanoplatform for efficient overcoming of cancer drug resistance.

Resistance to chemotherapy remains the primary obstacle for the successful treatment of cancers. Nanotechnology-based studies have developed many smart nanomedicines and efficient strategies to overcome multidrug resistance (MDR), which have brought new horizons to cancer therapy. Among them, protein-based nanomedicine represents an appealing drug delivery platform to realize safe and superior therapeutic effects due to its paramount biocompatibility with minimized toxicity. Herein we describe the rational design and construction of a novel protein-based nanocarrier using the naturally-occurring protein phycocyanin (PC) as the base material, to achieve safe and tumor-specific drug delivery. This cancer-targeting nanosystem (FA-PCNP@DOX) with bio-responsive properties exhibits positive targeting accumulation in resistant cancer cells and overcomes drug efflux by enhancing cellular uptake and retention time. Specifically, FA-PCNP@DOX inhibits the function of pumping proteins of the ABC family and triggers ROS-mediated apoptotic signaling pathways, thereby attaining highly efficient anticancer efficacy and overcoming drug resistance. Pharmaceutical studies demonstrate that FA-PCNP@DOX overwhelms DOX by sustained release in the blood, which verifies its prolonged circulation in vivo. Moreover, FA-PCNP@DOX efficiently accumulates in tumors and strengthens the tumor inhibitory effect of DOX by enhanced tumoral penetration. Importantly, FA-PCNP@DOX effectively reduces the hepatic, pulmonary, renal and cardiac toxicity caused by DOX. Therefore, as a new nanocarrier, this novel nanosystem could be further exploited as a safe and versatile nanoplatform for next-generation cancer therapy.