Construction Of Cobalt Doped Coordination Polymer Nanoenzyme Carrier And Its Delivery Of Curcumin In The Treatment Of Inflammatory Bowel Disease

Ulcerative colitis(UC)is a recurrent disease with an unknown etiology.With the continuous improvement of the national living standard,the incidence rate of UC is increasing year by year,which has seriously threatened the healthy life of the people.However,traditional drug treatment methods have drawbacks such as poor efficacy and significant toxic side effects,which are far from meeting the needs of clinical treatment.Therefore,it is imperative to develop and utilize new treatment methods.The ideal treatment method for UC should be precise and multifunctional,with specific targets such as antioxidant,anti-inflammatory,and mucosal repair.This requires us to be able to deliver a reasonable amount of therapeutic drugs to the corresponding targets in a reasonable manner and within a reasonable time,in order to achieve maximum efficacy and minimal toxic side effects.Curcumin(CCM),as a natural plant polyphenol,has antioxidant,scavenging oxygen free radicals,anti-inflammatory and other effects,and CCM has no side effects on the body.At present,studies have shown that CCM can alleviate colitis symptoms,but CCM has poor hydrophilicity,resulting in low bioavailability in vivo.Therefore,researchers enhance the drug’s properties through loading methods to achieve better therapeutic effects.Therefore,cobalt based nano coordination polymer,which is easy to synthesize and has good stability,was selected as the carrier of anti-inflammatory drug CCM in this study.Cobalt is one of the essential trace amounts in the human body and also a metallic element of vitamin B12.In addition,transition metal cobalt often appears in the form of+2 and+3 valence states,which can undergo oxidation-reduction reactions,thereby accelerating the transfer of interface electrons to ·O2-oxidation,enabling it to play the role of nanoenzymes.CCM has an enol like structure that can bind to metal ions through complex reactions.In view of the structural instability of most coordination polymer materials under acidic conditions,this advantage is used to achieve the pH responsiveness of controlled release of drugs under weak acidic conditions of inflammation,which can eliminate excessive reactive oxygen free radicals caused by inflammatory diseases and regulate the polarization of macrophages.The main research content of this paper is divided into the following three parts:1.Co doped ZIF-8 was synthesized by solution stirring method,and the structural correctness of Co-ZIF-8 was verified through tests such as SEM,TEM,XRD,FTIR,etc.Verify the nanoenzyme activity of Co-ZIF-8 through detection methods such as POD,SOD,CAT,and other nanoenzyme activities.The anti-inflammatory drug curcumin was loaded by room temperature stirring method,and the successful loading of CCM was proved by a series of physical and chemical characterization.Explore its impact on cell proliferation activity and anti-inflammatory properties at the cellular level.2.The nano Prussian blue analogue CoFe PBA was synthesized by room temperature resting method,and the structural correctness of CoFe PBA was verified by SEM,TEM,XRD,FTIR,etc.Verify the nanoenzyme activity of CoFe PBA by detecting methods such as POD,SOD,CAT and other nanoenzyme activities.The anti-inflammatory drug curcumin was loaded by room temperature stirring method,and the successful loading of CCM was proved by a series of physical and chemical characterization.Explore its impact on cell proliferation activity and anti-inflammatory properties at the cellular level.3.At the animal level,a colitis animal model was established in Balb/c mice induced by sodium dextran sulfate(DSS).The therapeutic effects and mechanisms of CCM-Co-ZIF-8 and CCM-CoFe PBA on colitis mice were compared and tested by evaluating DAI index,changes in mouse body weight,colon length,colitis factors,and colon tissue sections.At the same time,the biological safety of CCM-Co-ZIF-8 and CCM-CoFe PBA was systematically evaluated.Based on the Co based coordination polymer Co-ZIF-8 and CoFe PBA,their physical and chemical properties and pH responsiveness were studied,and it was confirmed that they can specifically target macrophages at the site of colitis,realize the controlled release of drugs,greatly improve the efficacy and reduce toxic and side effects.Therefore,it provides a drug delivery system with great potential for the treatment of UC.