DNA Nanotechnology-Mediated Fe-Curcumin Nanozyme Engineering Of Bifidobacterium Longum For Inflammatory Bowel Disease Therapy

Research purposesUsing deoxynucleic acid(DNA)engineering technology,bifidobacterium longum(BL)was modified to build an oral drug system.Meanwhile,the therapeutic effect of the drug delivery system on Inflammatory Bowel Disease(IBD)was explored and its deep mechanism was revealed from the aspect of microbiome.Research method1.DNA was connected to BL by amide method,and iron-curcumin was wrapped into the DNA network by RCA amplification of DNA.The coating rate and release rate were measured by confocal microscope and UV spectrometer.The effect of the drug delivery system synthesis on BL activity was evaluated by the method of coating plate and OD value measurement.2.The DNA-engineered bifidobacterium longum drug delivery system loaded with iron-curcumin(DNA@BL@Fe-Cur)was co-incubated with enteritis cells to evaluate its cell safety and reactive oxygen species(ROS)resistance.3.A total of 10 6-week-old healthy male C57B/L6 mice were randomly divided into PBS group and DNA@BL@Fe-Cur group and intragastric administration of 200μL PBS and DNA@BL@Fe-Cur(50 mg/kg),respectively.After 2 weeks,the mice were sacrificed,blood,major organs and colon were collected for safety evaluation.4.Thirty 6-week-old healthy male C57B/L6 mice were randomly divided into PBS group,PBS+3%DSS group,BL+3%DSS group,Fe-Cur+3%DSS group,DNA@BL+3%DSS group and DNA@BL@Fe-Cur+3%DSS group(n=5)to construct the mouse enteritis model.Except PBS group,other groups were given 3%DSS for induction of enteritis.After one week of induction,each group was intragastrically given 200μL PBS,PBS,BL(2.5×10~8/animal),Fe-Cur(50 mg/kg),DNA@BL(2.5×10~8/animal),DNA@BL@Fe-Cur(50 mg/kg)for five days,respectively.On the14th day,the mice were sacrificed,and blood,major organs,colon,and feces were collected for evaluation.Research result1.The DNA engineering mediated drug delivery system loaded with iron-curcumin for Bifidobacterium longum was successfully constructed,which had no significant effect on the activity of bifidobacterium longum.The coating efficiency was high,and the coating efficiency was time-dependent and the drug was released slowly.2.DNA@BL@Fe-Cur has no obvious cytotoxicity,and has good ability to eliminate reactive oxygen species and protect cells.DNA@BL@Fe-Cur’s ability to eliminate reactive oxygen species is dose-dependent.3.DNA@BL@Fe-Cur had good biological security.Compared with the PBS group,there were no obvious difference in the blood routine,biochemical and pathological sections of major organs of the mice in the DNA@BL@Fe-Cur group.4.DNA@BL@Fe-Cur showed good anti-inflammatory ability in mouse enteritis model.In the experimental stage,compared with mice in PBS+3%DSS group,there were no significant changes in hair,anus,feces and posture of mice in DNA@BL@Fe-Cur+3%DSS group.The body weight and colon length of mice in DNA@BL@Fe-Cur+3%DSS group were significantly higher than those in PBS+3%DSS group,and the difference was statistically significant.On the DNA@BL@Fe-Cur+3%DSS group,the abundance of bacteria was significantly increased,and the abundance of probiotics such as bifidobacteria and Lactobacillus was significantly increased.ConclusionIn this study,DNA engineering mediated drug delivery system loaded with iron-curcumin for Bifidobacterium longum was successfully constructed.The method was simple,the coating rate was high,and it had good biological safety.It is expected to be a new delivery method for enteritis drugs.