Construction And Biocompatibility Evaluation For A Multifunctional,Hyaluronic Acid-Based Coating

Objective:As a kind of material in human tissue and nature,Hyaluronic Acid(HA)is used to build a pollutant-resistance,hydration coating in the field of medical materials.Some studies suggest HA has anti-inflammatory,anticoagulant,and anti-hyperplasia functions.However,it is lack of systemetic evaluation on the biologic effects of HA due to the difficulties of HA immobilization.This study aims to construct a coating with fully grafting HA and evaluate the effect of the coating on anticoagulant,anti-inflammatory and anti-hyperplasia.Method:The amino-rich polyphenol-amine substrate coating(PPAC)was prepared by the phenol-amination reaction,which was used as the transition coating.Through the amidation reaction between the amino group of PPAC and the carboxyl group of HA,the grafting of different molecular weight HA(MW:5 K,38 K,300 K,1800 K)on PPAC was built.Amino and carboxyl were quantified by acid orange staining and toluidine blue staining,and the grafting amount of HA was detected by real-time quartz crystal microbalance.In 316 L stainless steel material surface,different molecular weight HA-PPAC coatings were constructed.The effect of HA-PPAC modified surface of blood contact materials on cell adhesion,activation,migration,aggregation was investigated by co-culturing of cell and material in vitro.Semi-in vivo animal experiments were conducted to evaluate the anticoagulant effect of PVC tubes with or without HA-PPAC modification.Results:Acid orange staining determined that a great deal of amino molecular was in PPAC surface.The deposition of HA on the PPAC was determined by toluidine blue staining method and the grafting amount of HA was 1122 ng/cm~2.Compared to the material without HA grafting,HA-PPAC material presented significant effects on the inhibition of proliferation and adhesion in endothelial cells,smooth muscle cells and macrophages as well as inhibition of platelet activation and fibrin adhesion.Among different molecular weight HA,the highest molecular weight of 1800 k Da HA has the best effect,which was used to construct HA-PPAC coating with the aim to evaluate the anticoagulant effect in semi-in vivo model.After 2 hours of circulation,the total thrombus weight of bare PVC tube was 284.8±16.1 mg,the total thrombus weight of PVC channel with PPAC modification was 318.2±10.7 mg,and the total thrombus weight of HA-PPAC was 67.3±8.9mg(P<0.001).Compared with the thrombus clogging rate of PVC and PPAC groups(83%and 92%,respectively),the thrombus clogging rate of HA-PPAC modified tubes was approximately 13%(P<0.001),indicating optimal anticoagulant effect of HA-PPAC.Conclusion:HA can be successfully grafted on PPAC by amidation reaction.HA-PPAC coating can inhibit cell adhesion,proliferation and has the function of anti-inflammation,inhibition of platelet activation and fibrin adhesion.1800K molecular weight HA is superoior to the other molecular weight HA.HA-PPAC presents the potential to optimize the biocompatibility of blood contact materials.