Surface Modification Of Inflammatory Response Polyurethane Films And Its Anti-inflammatory Effect

Local inflammation caused by heterotopic ossification is currently the treatment of cervical spondylosis in the artificial intervertebral disc replacement surgery the most common complications,which oral anti-inflammatory drugs is the most commonly used method of treatment of heterotopic ossification,due to the control can't achieve targeted release,so there are many toxic side effects.This subject is based on inflammatory tissue,there will be a lot of cholesterol esterase,using the enzyme on the amide bond and ester bond selective enzymatic hydrolysis,with indomethacin as an anti-inflammatory drug,the drug is prepared by binding the drug to the surface of the polyurethane with an amide bond or an ester bond to achieve the enzymatic response of the drug.Preparation of inflammatory response-type materials,so as to overcome the different patients with different time and severity of inflammation of the clinical differences.Firstly,grafting the drug onto the polyurethane surface through the amide bond.By using diphenylmethane diisocyanate and polyethyleneimine,the isocyanate group and the amino group were sequentially introduced on the surface of the polyurethane,and the drug was grafted onto the surface of the polyurethane through amide bond by EDC/NHS catalysis.The optimum reaction conditions and the highest drug grafting were obtained by the reaction of bromophenol blue,ninhydrin,SEM and EDS.Drug release test,the use of HPLC to test the release of enzyme-free drugs,found no enzyme response release effect.After the experimental verification and literature research,the use of amide bond grafting program is not feasible.The drug was then designed to graft the drug to the polyurethane surface via the ester bond.The indomethacin and N-hydroxyethyl acrylamide were subjected to esterification reaction,and infrared and nuclear magnetic tests were used to demonstrate that the product IDCM monomer was obtained.The IDCM monomer was polymerized and GPC was used to demonstrate that poly(IDCM)was obtained.Poly(IDCM)was used to perform the digestion experiment.Using HPLC and mass spectrometry,it was found that the ester bond was used as the cleavage site,and the indolemein structure was not changed.It was proved that cholesterol esterase was sensitive to ester bond,Stick to the surface of the polyurethane to provide the foundation.The IDCM monomer was introduced into the gel in the form of a hydrogel,and the polyurethane film containing the hydrogel layer on the surface was observed by SEM.The effect of the gel layer and the polyurethane film was demonstrated Force is relatively weak,easier to fall off,it is necessary to further improve.Through the inflammatory model test,it was found that the drug-loaded film had no effect on the inhibitory effect of the inflammatory membrane,but further experiments were needed to achieve the purpose of the study.