Preparation Of Nano-particles Based On Calcium Peroxide And Carbon Nanodots For Cancer Therapy

As an alternative to chemotherapy,gas therapy is considered a"green"treatment model with negligible side effects.In the family of gas transmitters,nitric oxide（NO）is involved in a series of physiological and pathological activities.However,the current NO prodrugs still face problems such as poor water solubility,low physiological stability,short half-life and large toxic and side effects,so the specific release of NO in tumor cells to achieve cancer therapy is still facing a huge challenge.H₂O₂is a new model of starvation therapy for tumor,which has significant tumor killing effect.The increase of H₂O₂concentration helps to accelerate the oxidation of L-arginine to NO,and may even react with NO to produce highly biocidal peroxy nitrite molecules,which further improves the effect of NO gas therapy.Therefore,hunger-like therapy has a significant enhancing effect on gas therapy,which will produce a synergistic effect of H₂O₂-NO.Therefore,based on the differences between tumor tissue microenvironment and normal tissue in p H,REDOX potential and other aspects,how to create intelligent nano drugs with stimulation-responsive drug release characteristics has become a research hotspot.In this work,we design a nanoscale catalytic drug CaO₂@CDs@BSA.Using CaO₂as H₂O₂donor,H₂O₂can be generated by combining with water in the weak acidic environment provided by tumor.The introduction of CaO₂solves the problem of insufficient endogenous H₂O₂.Using bovine serum albumin（BSA）to coat CaO₂and L-arginine carbon dots,nanoparticles with hydrophilic BSA-modified surface can escape the capture of reticuloendothelial system（RES）to the maximum extent,enhance the EPR effect,and achieve enrichment in tumor tissues.After the nanoparticles reached the tumor tissue by ERP effect,the microenvironment of the tumor tissue was slightly acidic（PH<6.5）,BSA molecules fall off the surface of nanoparticles due to the fracture of the amine bond,exposing CaO₂and CDs.Unprotected CaO₂reacts with water to generate O₂and H₂O₂.The resulting H₂O₂will further react with CDs to produce the treatment gas NO.Therefore,this nanocatalytic drug provides a new strategy for improving the effectiveness of gas therapy.