Preparation And Performance Research Of Hydrophilic Lubricious Coating On The Surface Of Guidewire

Interventional guidewire is the key to the success of interventional therapy with large amount of use and wide applied range.Lubricity is one of the important properties of the interventional guidewire.The high lubricity of the surface can effectively avoid the adhesion of plasma proteins and platelets in the blood,reduce the damage to blood cells and blood vessel walls,reduce the interference to the blood layer flow and inhibit the occurrence of coagulation.However,most the polymer materials used on the outer surface of interventional guidewires are hydrophobic,limiting their application.Combined the hydrophobic and structural characteristics of polyurethane with the experience of previous people and the characteristics of lubricious paint and coating which are imported product,this paper designed a double-layer(base coating and top coating)of hydrophilic coating on the polyurethane surface.The base coating was designed to have a similar structure to the substrate,with a densely cross-linked network,so the base coating as an intermediate connection layer can be bonded to the substrate and can provide a bonding point for the top coating.The top coating was designed as a hydrogel coating with interpenetrating network structure,which can achieve the purpose of hydrophilic and lubrication.The design of the base coating and the top coating contain similar component,so that the two layers combined into a complete coating firmly through the chemical bond and inter-molecular force.In this paper,the high-effective and low-cost ultraviolet curing technology was adopted.The base coating was cured from polyurethane acrylate(PUA)and active diluent(PEG200DA)and initiated by the photoinitiator Irgacure2959.PUA was designed and synthesized,and characterized by FT-IR,DSC and TGA.The base coating formula was determined by the test of coating cure-rate and the adhesion,the water resistance,the chemical resistance,the gel rate and the tensile of the films,in which PUA : PEG200 DA = 4 : 1,Irgacure2959 is 5 wt% of the coating,the concentration is 10 wt%.Finally,the coating was characterized by FT-IR,DSC and DMA.The top coating was cured from polyvinylpyrrolidone(PVP)and polyethylene glycol diacrylate(PEGDA)initiated by the photoinitiator Irgacure2959.PEG4000 DA was synthesized and confirmed by 1H NMR and FT-IR.The top coating formula was determined by the appearance evaluation,friction and firmness of the coating,in which PEG200 DA : PVPK90 = 35 : 65,Irgacure2959 was 2 wt% of the coating and the concentration was 6.5 wt%.The coefficient of friction(0.0075)of the surface of the guide wire modified by hydrophilic coating decreased by 98% compared with that(0.375)of unmodified guide wire,showing excellent lubricity.Finally,the appearance,structure,contact angle,water absorption,precipitation of PVPK90 and microparticle test of this hydrophilic coating were carried out.