Titanium Dioxide Nanoparticles Improve Blood Compatibility Of Blood Contact Materials By Photocatalytic Lithography

Good blood compatibility,especially good anticoagulant is the most important performance requirements to blood-contacting materials.It has been reported that titanium dioxide(TiO2)surface can generate reactive oxygen species(ROS)when UV irradiation.ROS can alter TiO2 surface which has the ability to impedance fibrinogen adsorption and conformational changes,and further inhibits platelet adhesion,activation and aggregation.Thereby TiO2 anticoagulant property has been improved.Photocatalytic lithography(PCL)is a method of using the photogenerated ROS from the TiO2 surface to modify the nearby surface of the other materials.Some studies suggest that using a thin film of TiO2 stamp can make the photogenerated ROS migrate to the adjacent surface of the target materials by PCL,which can improving the anticoagulant of the target materials.However this method also has some disadvantages,such as unable to modified rough/curved surfaces,low modification efCiciency,the tedious preparation of stamp and so on.Using TiO2 nanoparticles instead of TiO2 film and treating the surface of the target materials by PCL can solve the above-mentioned drawbacks.Compared with TiO2 film,TiO2 nanoparticles could adhere to the rougj/curved surfaces as well as higher photocatalytic activity characteristic.Therefore,in order to improve the anticoagulant of target materials,in this paper,using TiO2 nanoparticles treat a variety of commonly biological materials by PCL.Firstly,samples were characterized by a series of materials characterization,including atomic force microscopy(AFM),confocal laser scanning microscope(CLSM),scanning electron microscopy(SEM)and water contact angle(WCA).Different samples have different surface roughness.Si is located in nanoscale roughness.And netal surface roughness is larger.SEM results showed that TiO2 nanoparticles were easy to fall off from the sloothed surface of Si,PU.However on the rough metal surface is relatively stable.WCA results suggested that the TiO2 nanoparticles by PCL significantly improved the hydrophilic of kinds of materials.At the same time,optimal process was chosen through platelet adhesion test and water contact angle test.In which TiO2 particles suspension concentration is 5mg/ml;and Ti,Ni-Ti ultraviolet irradiation time is 2h,besides Si,316L SS,Co-Cr-Mo,PU UV irradiation time is 3h.By hemolysis test,the platelet adhesion assay,Static liquid whole blood test and fibrinogen adsorption experiments proved that the modified samples surface by PCL has good antithrombogenicity.Endothelial cell and factor test,smooth muscle cells test,macrophages and factor testing proved that samples were friendly and found no adverse effects.To further explore the blood compatibility and tissue compatibility of surface of modified samples,SD rats subcutaneously embedded and stainless steel wire were implanted in the abdominal aorta experiments showed that modified sample has a good histocompatibility.In addition,this article combined with PCL and micro-pattern technology,building protein and cell micro-pattern.