Tumor-targeted glycogen nanoparticles loaded with hemin and glucose oxidase to promote tumor synergistic therapy.

Strategies which are used to address the low levels of intracellular hydrogen peroxide and the development of biocompatible catalysts still need to be fulfilled in tumor chemodynamic therapy. Therefore, a novel tumor-targeted glycogen-based nanoparticle system (GN/He/GOx/HA) was developed to co-deliver hemin (He) and GOx, which can self-supply glucose formed upon degradation of glycogen by α-glycosidase in the lysosome environment, in order to achieve synergistic antitumor therapy. Hyaluronic acid (HA) was selected as the outer shell to protect the activity of GOx, and to increase the uptake by tumor cells via CD44 receptor-mediated endocytosis. GN/He/GOx/HA NPs had a good stability in the blood circulation, but fast release of the therapeutic cargos upon intracellular uptake. Hemin had a cascade catalytic reaction with GOx. Furthermore, GN/He/GOx/HA NPs had the strongest cytotoxicity in Hela cells in a glucose concentration dependent manner. The NPs could efficiently produce reactive oxygen species in tumor cells, resulting in a decrease in the mitochondrial membrane potential and apoptosis of tumor cells. The in vivo results showed that the drug-loaded nanoparticles had good safety, biocompatibility, and efficacious antitumor effect. Therefore, the glycogen-based nanoparticle delivery system provides potential application for self-enhancing CDT, which can be used for effective antitumor therapy.

Dual-Functional Peptide Driven Liposome Codelivery System for Efficient Treatment of Doxorubicin-Resistant Breast Cancer.

BACKGROUND: The active-targeted drug delivery systems had attracted more and more attention to efficiently overcome multidrug resistance (MDR) in cancer treatments. The aim of the work was to develop a multifunctional nano-structured liposomal system for co-delivery of doxorubicin hydrochloride (DOX) and celecoxib (CEL) to overcome doxorubicin resistance in breast cancer. METHODS: A functional hybrid peptide (MTS-R8H3) with unique cellular penetrability, endo-lysosomal escape and mitochondrial targeting ability was successfully synthesized using solid phase synthesis technology. The peptide modified targeted liposomes (DOX/CEL-MTS-R8H3 lipo) for co-delivery of DOX and CEL were formulated to overcome the chemoresistance in MCF/ADR cells. RESULTS: DOX/CEL-MTS-R8H3 lipo showed nanosized shape and displayed high stability for one month. The cytotoxicity effect of the co-delivery of DOX and CEL through peptide modified liposomes had remarkable treatment efficacy on killing MCF/ADR cells. Targeted liposome exhibited greater cellular entry ability about 5.72-fold stronger than DOX solution. Moreover, as compared with unmodified liposomes, the presence of MTS-R8H3 peptide entity on liposome surface enhanced the mitochondrial-targeting ability and achieved effective reactive oxygen species (ROS) production with significant inhibition of P-gp efflux activity. CONCLUSION: The study suggested that the DOX/CEL-MTS-R8H3 lipo is a promising strategy for overcoming drug resistance in breast cancer treatments with high targeting inhibition efficiency.

Bacteria-mediated cancer therapies: opportunities and challenges.

In recent years, cancer therapy strategies utilizing live tumor-targeting bacteria have presented unique advantages. Engineered bacteria have the particular ability to distinguish tumors from normal tissues with less toxicity. Live bacteria are naturally capable of homing to tumors, resulting in high levels of local colonization because of insufficient oxygen and low pH in the tumor microenvironment. Bacteria initiate their antitumor effects by directly killing the tumor or by activating innate and adaptive antitumor immune responses. The bacterial vectors can be reprogrammed following advanced DNA synthesis, sophisticated genetic bioengineering, and biosensors to engineer microorganisms with complex functions, and then produce and deliver anticancer agents based on clinical needs. However, because of the lack of knowledge on the mechanisms and side effects of microbial cancer therapy, developing such smart microorganisms to treat or prevent cancer remains a significant challenge. In this review, we summarized the potential, status, opportunities and challenges of this growing field. We illustrated the mechanism of tumor regression induced by engineered bacteria and discussed the recent advances in the application of bacteria-mediated cancer therapy to improve efficacy, safety and drug delivery. Finally, we shared our insights into the future directions of tumor-targeting bacteria in cancer therapy.