Preparation Of Dissolving Microneedle Arrays Based On Photodynamic Therapy And Its Efficacy And Mechanism For Rheumatoid Arthritis

Objective Screen the best needle shape of dissolving microneedle arrays,established an optimized preparation method and evaluation system for 5-ALA dissolving microneedle arrays(5-ALA& DMNA).In vitro cell experiments and in vivo experiments on adjuvant arthritis rat models were used to explore the efficacy and mechanism of photodynamic therapy based on 5-ALA& DMNA on rheumatoid arthritis(RA).Method Through fluorescence spectrophotometer,DCFH-DA kit assay,MTT,cell migration experiment and cell apoptosis experiment,explored the in vitro efficacy and mechanism of 5-ALA based on photodynamic therapy on RA-FLs cells;Through the preparation,morphological observation,insert ability and dissolution ability of various needle-shaped dissolving microneedle arrays,the best DMNA needle shape was selected for encapsulation of 5-ALA;Exploring the feasibility of transdermal delivery of 5-ALA through the preparation optimization and characterization evaluation of 5-ALA&DMNA;a rat model of adjuvant arthritis(AA model)was established,and the paw swelling degree,X-ray imaging,HE stained pathological section and immunohistochemical results were analyzed,and explored the therapeutic effect of photodynamic therapy based on 5-ALA&DMNA on rheumatoid arthritis.Results By detecting the peak time of Pp IX production in RA-FLs cells,it is determined that 14 h after 5-ALA administration is the best time to give light.Through the DCFH-DA kit assay,it was confirmed that the interaction between 5-ALA and light(635nm,100 m W)can cause RA-FLs cells to produce a large amount of reactive oxygen species(ROS),indicating that 5-ALA has excellent photodynamic effects and can be used for RA treatment;5-ALA did not produce ROS in RA-FLs cells,which proved that the photodynamic effect based on 5-ALA had the characteristics of targeting RA-FLs cells.The cell survival rate was detected by the MTT experiment,and the results showed that 5-ALA based on photodynamic therapy produced a significant killing effect on RA-FLs cells through ROS,while the killing effect on normal FLs cells was less,indicating that it could used in the treatment of RA,had a certain targeting effect and high safety,which was consistent with the results of the DCFH-DA experiment.The morphology,insertion and dissolution ability of four different needle shapes of DMNA of cone,cone-cylinder,rectangular pyramid,hexagonal pyramid were investigated,and the results showed that the insertion and dissolution ability of cone DMNA were obviously superior.Compared with the other three shapes of DMNA,and the needle was smooth and complete,it is the best needle shape.The optimized 5-ALA@DMNA needle has a regular shape,can successfully puncture the skin,and has a stable drug loading;the DMNA accessories have good biocompatibility and safety;The above results indicate that 5-ALA@DMNA could carry out effective,safe and stable drug delivery,laying the foundation for photodynamic therapy based on 5-ALA&DMNA in the treatment of RA.In vivo experimental results of adjuvant arthritis(AA)rat model show that photodynamic therapy based on 5-ALA@DMNA could significantly improve paw swelling in AA rats,inhibit synovial tissue proliferation,inflammatory factor infiltration and pannus formation,and had a good therapeutic effect on AA Rat joint inflammation.Conclusion 5-ALA based on photodynamic therapy could kill RA-FLs cells by generating ROS,which could be used for the treatment of RA,and has a certain targeting effect and high safety.The insertion and dissolution ability of the cone DMNA was obviously better than that of the cone-cylinder,rectangular pyramid,hexagonal pyramid DMNA,and the needle was smooth and complete,which was the best needle shape.The 5-ALA&DMNA had a smooth and complete surface,could successfully puncture the skin,has a stable drug loading,and the preparation of DMNA accessories was safe,had good biocompatibility,and could deliver effective,safe,and stable drug delivery.Photodynamic therapy based on 5-ALA@DMNA could significantly improve paw swelling in AA rats,inhibit synovial tissue proliferation,inflammatory factor infiltration and pannus formation,and had a good therapeutic effect on joint inflammation in AA rats.