Anti-tumor Properties Of Function Alcobalt Sulfide Nano Materials

Cancer has become one of the most serious and difficult diseases facing human beings.It suffered from high mortality and poor therapeutic effect.Nowadays,chemotherapy,surgery and radiotherapy are widely used to treat cancer.However,these therapeutic methods will bring irreversible damage at the same time.Therefore,it is very important to develop effective anti-tumor therapy.At present,some non-invasive therapies have been developed,such as photothermal therapy?PTT?and photodynamic therapy?PDT?.They have shown the certain application prospect in overcoming traditional treatment methods.In PTT and PDT,the choice of light source becomes the key to treatment.Near infrared?NIR?possess some advantages compared with ultraviolet?UV?and visible light,such as small damage and strong penetration.At present,more and more people focus on the research of NIR sensitive materials.Among them,transition metal sulfides such as cobalt sulfide?CoS_x?have been widely concerned by researchers as a result of high NIR harvest.In view of this property,we synthesized different morphologies and compositions of CoS_x nano materials,and finished a series of structure and performance characterization of the as synthesized nano materials.Furthermore,we haveestablished the relationship of construction.Meanwhile,with its unique light absorption capacity and morphological characteristics,we have completed drugs loading,and formed the synthetic treatment of PTT,PDT and chemotherapy,so that improved the anti-tumor performance.Meanwhile,Co ion possesses single electron and paramagnetism,so it can be used as great contrast agent for MRI imaging.Therefore,in this paper,CoS_x based nano photosensitive materials were constructed to study their antitumor properties under the guidance of MRI.The specific research contents are as follows:?1?A nanoheterostructure was constructed by and N-doped carbon.Firstly,hollow Co₃S₄ nanospheres about 80 nm coated with N-doped carbon shell?CSC2?were synthesized by using polyacrylonitrile nanospheres as sacrificial template as well as N source for N-doped carbon.The heterostructure reveals the higher NIR absorbance and photothermal conversion efficiency?57.5%?thanks to the composite of carbon shell.In addition,the heterostructure also reveals the nearly two times reactive oxygen species?ROS?generation as pure Co₃S₄.The formation mechanism was investigated,revealing that it is the photo-exited electron and dissolved O₂ to determine ROS generation and the effective segregation of photogenerated charge in heterostructure endows the great performance on PDT.In view of Co,the sample can be used as magnetic resonance imaging?MRI?contract.What's more,CSCn also exhibit the considerable biodegradation ability.After the loading of Dox,CSC2@PEG-Dox can integrate of multi-model imaging?MRI and thermal imaging?and the synergy therapy?chemotherapy/PDT/PTT?,making the potential theranostic application for anticancer.?2?Double-layer Mn-CoS@C?CMS2/C2 DSHSs?hollow cages were synthesized successfully,and compared the effects of Mn and carbon doping with CoS.Firstly,we have synthesized the cube Co-Mn precursor,then calcined and vulcanized to form CMS2/C2 DSHSs with special morphology.Compared with the initial CoS,the CMS2/C2 DSHSs shows higher light absorption and photothermal conversion rate,and the generated heat can also be used in photothermal imaging.Meanwhile,the production of ROS is about six times compared with CoS.Furthermore,Co and Mn cooperated with Fenton like reaction to solve the problem of oxygen deficiency in vivo,so ROS production was further strengthened.In addition,due to the unpaired electrons of cobalt,CMS2/C2 DSHSs has become excellent MRI contrast agent,and combination of Mn and Co elements also made CMS2/C2 DSHSs empolyed in CT imaging.Furthermore,DOX was loaded into the cavity of CMS2/C2 DSHSs to form chemotherapy.Therefore,CMS2/C2@BSA DOX DSHSs has become a potential multi-mode imaging?MRI,CT,thermal imaging?guided synthesize therapeutic?PTT,PDT,chemotherapy?platform.?3?Based on the above research work,we found that photogenerated electrons of semiconductor PS directly affect the production of ROS.Therefore,in order to further promote the photodynamic effect,the hollow CoS/CdS2 nano hollow spheres are successfully synthesized.CdS is widely used in photocatalytic material,can produce more ROS.After CdS being introduced into the treatment system,more ROS will be produced compared with CoS.Meanwhile,CoS/CdS2 is also a great photothermal reagent.As a result,CoS/CdS2 has become potential nano synergistic therapy platform.