Fig. 6
From: Bioenzyme-based nanomedicines for enhanced cancer therapy
Reproduced with permission from [82]. Copyright 2021, Springer Nature
a The synthetic procedures of hybrid enzyme nanogel (FIGs-LC) include: (1) self-assembly of Fe3O4 nanoparticles-encapsulated polystyrene-block-poly (acrylic acid) (PS-b-PAA) micelles (Fe3O4@PS-b-PAA) in selective solution; (2) the formation of ICG-loaded hybrid nanoparticles (Fe3O4@IHPs) by doping ICG and introducing organic silane 3-mercaptopropyltrimethoxysilane (MPTMS); (3) acid phosphatase (AP)-triggered hydrogel coating onto Fe3O4@IHPs, denoted with Fe3O4@IHPs nanogels (FIGs); (4) immobilization of LOx and CAT into FIGs, the final particles are denoted by FIGs-LC. b Schematic circuit diagram for the peroxisome-inspired therapeutic mechanism of FIGs-LC based on the dual-enzyme-regulated ROS generation with GSH and NIR activation: the intratumoral lactate and H2O2 are catalyzed by LOx and CAT (resistor regulation) to generate H2O2 and O2, respectively. Then, H2O2 is used to produce·OH (current I1) in the presence of Fe3O4 nanoparticles within GSH-enriched acidic tumor microenvironment (Switch-1, S1), leading to the cancer cell death (bulb on). In the reaction, the produced O2 is converted into 1O2 (current I2) under the irradiation of an 808 nm laser (Switch-2, S2), which can also cause significant cell death (bulb on). Both CDT and PDT can be executed independently and induce the death of cancer cells, as well be activated simultaneously (S1 and S2 are connected) to achieve improved antitumor therapy. c Change in relative tumor volume during the treatment. d Average weight of excised tumors from the tumor-bearing mice after 21 days of treatment.