Synthesis And Anti-Tumor Properties Of Co And C-Based Nanomaterials

Malignant tumors(cancer)have been one of the major diseases that threaten human health.Each year,there are approximately 14 million new cancer patients and nearly 8million deaths.Traditional anti-tumor methods include chemotherapy,surgery,and radiotherapy,which not only has large toxic and side effects,but also are prone to recurrence and metastasis.Therefore,it is urgent to develop new and efficient anti-tumor systems to stimulate immune responses and improve anti-tumor effects.Recently years,some new anti-tumor methods,such as photodynamic therapy(PDT),photothermal therapy(PTT)and sonodynamic therapy(SDT)are minimally invasive,spatiotemporally selective,less drug resistant and more effective in treatment.The advantages of high efficiency have attracted widespread attention.On this basis,the synergistic integration of multiple diagnosis and treatment methods can further improve the anti-tumor performance.Based on this,Co-based and C-based nanomaterials were synthesized in this paper,and a synergistic anti-tumor platform of PTT/PDT,SDT and CDT was realized under the guidance of multimodal imaging.The specific research contents are as follows:(1)The FeCo-LDH precursor was synthesized by a solvothermal method,and the FeS₂/CoS₂@PEG nanoheterojunction was prepared by hydrothermal vulcanization.The morphology is a lamellar structure,and the size is about 100 nm.The material has high absorption in the near-infrared second region(NIR-II),high photothermal conversion rate(50.5%)and photothermal imaging capability.The nanoheterojunction exhibits a Z-scheme charge transfer mechanism that retains the high redox capacity of holes and electrons,enabling NIR-II photocatalytic water splitting for oxygen production and ROS generation.In addition,the heterostructure promotes electron transfer and suppresses electron and hole recombination,which enhances the photocatalytic performance.Due to the presence of Fe²⁺and Co²⁺in the system,the nanomaterial can transform hydrogen peroxide highly expressed in the tumor microenvironment,generate toxic ROS,and realize chemodynamic therapy.In addition,FeS₂/CoS₂@PEG also has a considerable biodegradation function,which can be gradually degraded into nanoparticles of<10 nm and excreted from the body.At the same time,due to the unpaired 3d electrons in Fe and Co elements,FeS₂/CoS₂@PEG nanosheets can synergistically integrate photothermal imaging/NMR imaging with PTT/PDT/CDT therapy,which improves the antitumor effect.(2)Preparation of Co-based Bruceland nanocubes as precursors,and through high temperature calcination and annealing,double-layer Co₃O₄ hollow nanospheres are obtained.Nitrogen-doped carbon dots were subsequently added,followed by phosphating,to prepare CoP@C@PEG nanoheterostructures.The nanomaterial can generate ROS under ultrasonic conditions to realize sonodynamic therapy.In addition,under the condition of non-sonication,it exhibits good biological safety,which makes the material have specific tumor suppressing ability.Meanwhile,the introduction of C quantum dots enhanced the acoustic-induced electron-hole separation and promoted ROS generation.In addition,CoP@C@PEG can catalyze H₂O₂ to generate oxygen,relieve tumor hypoxia,and enhance the acoustic power effect.The nanocomposite exhibits good biodegradability and can be excreted through the feces and urine of mice within 14 days after administration.CoP@C@PEG hollow nanospheres can integrate MR,CT imaging and SDT,showing good tumor diagnosis and treatment effect.(3)Using methylene blue as carbon source,carbon nanomaterials were synthesized by hydrothermal method.The sulfuric acid added in the preparation process is both an oxidant and a catalyst for dehydration polymerization,which plays a crucial role in the formation of carbon nanomaterials.Compared with the raw materials,the prepared carbon nanomaterials exhibited high NIR-II absorption ability and high photothermal conversion to ROS generation ability,and were good NIR-II photosensitizers.This is due to the higher conjugated structure of the polymerized carbon material.In addition,we also found that the photosensitivity is also related to the aromatic structure and atomic composition of the precursor material.Ideas were explored for the development of carbon-based PTT and PDT nano-therapeutics.