The prosperity of chemodynamic therapy provides a new strategy for tumor treatment. However, the lack of reactive oxygen species and the specific reductive tumor microenvironment have limited the further development of chemodynamic therapy. Herein, we reported a Fe-based cyclically catalyzing double free radical system for tumor therapy by catalyzing exogenous potassium persulfate (K2S2O8) and endogenous hydrogen peroxide (H2O2). Sufficient amounts of Fe3+ and S2O82- were delivered to tumor sites via tumor-targeted hyaluronic acid (HA) encapsulated mesoporous silica nanoparticles (MSNs) and released under the dual stimulation of acid and hyaluronidase (HAase) in the tumor microenvironment. Fe3+ was reduced to Fe2+ by the reducing agents of loaded tannic acid (TA) and intracellular glutathione (GSH), and Fe2+ was subsequently reacted with S2O82- and endogenous H2O2 to produce two types of ROS (˙OH and SO4-˙), showing an excellent anti-tumor effect. This process not only supplied Fe2+ for the catalysis of active substances, but also reduced the concentration of reduced substances in cells, which was conducive to the existence of free radicals for the efficient killing of tumor cells. Therefore, this iron-based catalysis of exogenous and exogenous active substances to realize a dual-radical oncotherapy nanosystem would provide a new perspective for chemodynamic therapy.

Up to now, a variety of hydrogels have been explored for strain sensors, but simultaneous accomplishment of high stretchability, rapid full self-recovery, favourable transparency and excellent sensing properties through employing inexpensive raw materials and simple synthesis approach remains challenging. Herein, AlCl3.6H2O aqueous solution, as a sort of solvent, was utilized to facilely manufacture high performance hydrogel ionic conductors with novel one-pot dual ionic cross-linking approach. The resulting model hydrogel sensors manifested favorable transparency (>84%), excellent stretchability (1400%), good mechanical strength (421.2 kPa), outstanding rapid self-recovery (nearly full recover) and good anti-fatigue. Furthermore, our ionic hydrogel sensors demonstrated brilliant stretching sensitivity (gage factor as high as 9.6), and it displayed stable sensing performance for repeatedly real-time monitoring of both large and subtle deformations. Hence, the hydrogel sensors successfully achieved critical features combination and could serve as wearable devices to sense various human motions.

The core-shell nano drug loaded particle DOX@AuNC@HA???DAH???was prepared by a simple one potmethod using gold nanocage???AuNC???as the core???sulfhydryl modified hyaluronic acid???LC-HA???as the shell and doxo???rubicin hydrochloride???DOX???as the drug model.The gold nanocage provides a container for drug loading and endowsthe carrier with photothermal properties.The modified hyaluronic acid encapsulates the gold nanocage and providespH/enzyme response and targeted mediating functions.The structure of DAH was characterized???and the drugloading???controlled release performances???cell uptake and cytotoxicity were studied.The results show that the DAHnanoparticles with the core-shell structures have a high drug loading capacity???a good cycle stability and excellentphotothermal conversion efficiency under the irradiation of laser source.In phosphate buffer solution with a pH of7.4???DAH has high stability???the DOX leakage ratio in20h is less than20%???and DAH exhibits good stimulusresponse and can release the loaded drug quickly in acidic???hyaluronidase and photothermal action environment.In addition???DAH is more easily uptaken by tumor cells in cell experiments???which demonstrates certain targeting???showing better stimulus responsiveness.When chemotherapy and photothermal therapy works together???the activity oftumor cells is greatly weakened???showing the advantages and potential of combined therapy.