A MXene-Based Bionic Cascaded-Enzyme Nanoreactor for Tumor Phototherapy/Enzyme Dynamic Therapy and Hypoxia-Activated Chemotherapy

The enzyme-mediated elevation of reactive oxygen species (ROS) at the tumor sites has become an emerging strategy for regulating intracellular redox status for anticancer treatment.Herein,we proposed a camouflaged bionic cascaded-enzyme nano-reactor based on Ti3C2 nanosheets for combined tumor enzyme dynamic therapy (EDT),phototherapy and deoxygenation-activated chemotherapy.Briefly,glucose oxidase (GOX) and chloroperoxi-dase (CPO) were chemically conjugated onto Ti3C2 nanosheets,where the deoxygenation-activated drug tirapazamine (TPZ) was also loaded,and the Ti3C2-GOX-CPO/TPZ (TGCT) was embed-ded into nanosized cancer cell-derived membrane vesicles with high-expressed CD47 (meTGCT).Due to biomimetic membrane camouflage and CD47 overexpression,meTGCT exhibited superior immune escape and homologous targeting capacities,which could effectively enhance the tumor preferential targeting and internalization.Once internalized into tumor cells,the cascade reaction of GOX and CPO could generate HClO for efficient EDT.Simultaneously,additional laser irradiation could accelerate the enzymic-catalytic reac-tion rate and increase the generation of singlet oxygen (1O2).Furthermore,local hypoxia environment with the oxygen depletion by EDTwould activate deoxygenation-sensitive prodrug for additional chemotherapy.Consequently,meTGCT exhibits amplified synergistic thera-peutic effects of tumor phototherapy,EDT and chemotherapy for efficient tumor inhibition.This intelligent cascaded-enzyme nanoreactor provides a promising approach to achieve concurrent and significant antitumor therapy.