The Copper-based MOF Materials Of The Endogenous H₂S Response Were Used For Enhanced Chemodynamic Therapy

Chemodynamic therapy(CDT)is a new tumor treatment technology based on Fenton or Fenton-like reaction.Through Fenton or Fenton-like catalysts,hydrogen peroxide(H₂O₂)is catalytically degraded into highly toxic hydroxyl radicals(?OH)that can kill tumor cells.This method has been widely studied due to its characteristics of minimally invasive and high tumor selectivity.However,the low catalytic efficiency of Fenton or Fenton-like catalysts limits their further development.Therefore,it is urgent to explore strategies to enhance the Fenton or Fenton-like catalytic effect,and then improve the CDT therapeutic effect.Based on this,this paper designed two Cu-based MOF materials to improve the active sites of the catalyst,improve the reaction temperature,and explored the enhancement mechanism.The first part:Colon cancer highly expresses endogenous hydrogen sulfide(H₂S),which can consume the generated?OH and reduce the CDT therapeutic effect.To overcome this problem,we constructed the Cu(bpy)₂(OTf)₂ two-dimensional Fenton reagent.This material can not only react with endogenous H₂S highly expressed in colon cancer,adjust its reducing environment,but also has a larger specific surface area and more active sites,which can further improve its Fenton-like reaction effect.More interestingly,the material and Cu_2-xS generated by the endogenous H₂S reaction in colon cancer show strong absorption in the near-infrared(NIR)-II,which can be used for NIR-II photothermal therapeutic reagents,improve the temperature of the Fenton-like reaction and accelerate the generation of?OH.In vivo and in vitro experiments proved that based on the above enhancement strategy,this reagent has an excellent CDT therapeutic effect,effectively inhibiting the growth of tumors,and providing a new material for the CDT of tumors.The second part:In order to achieve the accurate diagnosis and efficient treatment of colon cancer,we constructed the Cu(6-FDA)₂ MOF nanoscale reagent.This reagent encounters high endogenous H₂S expression in colon cancer,which will be interpreted to release 4,4-hexafluoropropylene phthalic acid ligand containing F.Due to the paramagnetic relaxation enhancement(PRE),this ligand is released after obvious ¹⁹F-MR imaging,achieving accurate diagnosis of colon cancer.At the same time,both Cu and H₂S reaction can generate Cu_2-xS with photothermal and CDT therapeutic functions,which can be used for the synergistic treatment of colon cancer.Then in vivo and in vitro experiments proved that this reagent can accurately diagnose colon cancer by ¹⁹F-MR imaging,while inhibiting its growth through synergistic therapy.