Plasma surface modification equipment for medical devices

• Categories:Technical Support
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2020-11-05
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(Summary description)Another important application of plasma surface modification equipment is to promote cell growth or protein binding, thereby reducing thrombus formation. The polytetrafluoroethylene coating and organosilicone monomer have blood compatibility. The fluorocarbon ratio (F/C ratio) and the presence form of wettability in the film are obviously closely related to the absorption and storage of fibrinogen, a protein in the blood that participates in the coagulation process of blood. PECVD can be used to prepare polytetrafluoroethylene films with different surface morphology.   Silane - like films can be obtained by plasma polymerization of organosilicon monomer. The SiCHO compound was applied to the blood filter and the hollow fiber membrane of polypropylene to coat the activated carbon particles. Hemoperfusion device is to circulate the blood of the patient's artery into the hemoperfusion device, so that the poisons and metabolites in the blood are adsorbed and purified, and then injected back into the body. The absorbent of hemoperfusion apparatus mainly includes activated carbon, enzyme, antigen and antibody, etc. The carbon particles must be coated with a polymer film to prevent fine particles from entering the blood. Similarly, the microporous polypropylene blood oxygenator needs to be coated with a silane polymer film to reduce the roughness of the polypropylene surface and thus reduce damage to blood cells.   Heparin and heparin-like molecules, collagen, albumin, and other life-giving molecules can be fixed on the surface of the polymer and act as antithrombotic agents. So to fix these molecules to the surface of the polymer, you need to activate the polymer and respond to the grafted molecules. This process mainly adopts the experimental and empirical method, and the graft base groups used are mostly NH3, OH and -COOH, which are mainly obtained from raw materials supplied by non-precipitation. Amino functional groups appear on the surface of materials treated by ammonia gas plasma, which are similar to liver phosphorus ester and can be used as attachment points of anticoagulants. Examples of this kind of plasma used in vitro medical utensils include cleaning and modification of petri dishes for experiment or drug production, and surface modification of microporous plates. The surface modification can also improve the biocompatibility of human implants. For example, the biocompatibility of artificial blood vessels, contact lenses and drug delivery implants could be improved by improving the adhesion of blood-capacity coatings to materials. In some applications, such as contact lenses and intraocular lens materials, surface treatments can also reduce protein or cell adhesion.   Many materials encourage proteins to bind, leading to the formation of blood clots. Anticoagulant coating can effectively reduce surface clotting and thrombosis, but antithrombotic materials often cannot be well combined with polymer surface. The active free radicals in plasma were used to enhance the effective chemical bond on the surface of the material through heparinization or grafting of antithrombolytic groups. The effect of material surface modification depends on a number of factors, including the choice of material matrix, composition of antithrombotic coating, and service life of the modified material. Animal experiments showed that the plasma-activated modified polyurethane catheter showed no protein attachment after 30 days of use. The plasma-activated polyurethane catheter without heparin coating showed a small amount of protein attachment. There was serious thrombus in the fluid guide tube without plasma surface modification. Compared to the untreated blood filter, the improved blood filter can significantly reduce the amount of platelet adhesion.