Study On Surface Modification And Blood Compatibility Of Polylactic Acid Film

Developing the hemolysis membrane with good hemocompatibility and permselectivity is in urgent need.In this study,the substrate membrane was fabricated with environment-friendly material poly(lactic acid)(PLA).Aim to improve the hemocompatibility of PLA membranes,functional graphene oxide was immobilized onto the membrane surface.This study is expected to offer guidance to solve the hemocompatibility of materials.The preparation of PLA membrane and hemocompatibility of reduced graphene oxide modified PLA membrane:the PLA membranes were prepared by nonsolvent induced phase separation(NIPS)process.The structure of PLA membrane was controlled by changing the ratio of N-Methyl pyrrolhdone(NMP)and 1,4-dioxane and the temperature of coagulation bath.Porous structures on the PLA membranes surface and macrovoids across the PLA membranes were fabricated when the ratio of NMP and 1,4-dioxane was 4:1 and the temperature of coagulation bath was 10 degrees Centigrade.At the same time,the pure water flux of the PLA membrane was 640.2 L/m2·h.The reduced graphene oxide with different reduced time was immobilized on PLA membrane by suction filtration.Large numbers of platelets were adhered on the surface of rGO modified membrane and the hemolysis ratios were higher than 5%.The hemocompatibility of PLA membranes prepared by immobilizing carboxylated graphene oxide via surface amination method:in this study,the self-polymerization and deposition of dopamine were catalyzed by ammonium ferrous sulfate and hydrogen peroxide.The dopamine self-polymerized in 40 min when the concentration of ammonium ferrous sulfate and hydrogen peroxide was 5 mM and 20 mM,respectively.And the self-polymerization of dopamine was catalyzed by Fe2+and NH4+.Amino groups were introduced on the PLA membrane surface,and then the carboxylated graphene oxide(GOCOOH)nanoplatelets were immobilized onto the surface of PLA membranes.The recalcification time of modified PLA membrane was prolonged 100 s and the hemolysis ratio was as low as 2.8%when the immersing concentration of GOCOOH was 0.68 mg/mL.The hemocompatibility of the PLA membrane was improved.The hemocompatibility of PLA membranes prepared by immobilizing carboxylated graphene oxide via mussel-inspired method:in this work,the influence of the amount of carboxylic group on the hemocompatibility of modified PLA membrane was investigated.Dopamine-g-carboxylated graphene oxide(DA-g-GOCOOH)was prepared.The hemocompatibility of PLA membrane modified with DA-g-GOCOOH which has higher amout of carboxylic groups was better.The platelet adhesion on modified PLA membrane surface was suppressed,the recalcification time of the modified PLA membrane was prolonged 100 s and the hemolysis ratio was as low as 0.13%,when the immersing concentration of DA-g-GOCOOH was 2.0 mg/mL.Furthermore,the modified PLA membrane showed excellent dialysis performance,especially for the clearance of middle molecule toxin,which was up to 24.5%and the BSA retention rate was 95.6%.Moreover,the DA-g-GOCOOH immobilized layers were relatively stable after incubating in water for 48 h.The hemocompatibility of PLA membranes prepared by immobilizing sulfonated graphene oxide via mussel-inspired method:the heparin-mimetic sulfonated graphene oxide(DA-g-SGO)was immobilized on the PLA membrane via mussel-inspired method.The hemocompatibility of the modified PLA membrane was improved by the anticoagulation effect of sulfonate groups and the increasement of the hydrophilicity and electronegativity of the PLA membrane.The platelet adhesion on modified PLA membrane surface was suppressed,the recalcification time of the modified PLA membrane was prolonged 110 s and the hemolysis ratio was as low as 1.6%,when the immersing concentration of DA-g-SGO was 2.0 mg/mL.