Immobilization Of Chiral Tartaric Acid On Ti-O Surface And Investigation On Its Generation Of Nitric Oxide And Hemocompatibility

Chirality is the basic characteristic of the life system.The vast majority of the organic molecules that make up the living body are chiral molecules and exhibit a high degree of chiral choice,so that different chiral molecules interact with the biological system to exhibit different biology features.In this paper,chiral tartaric acid and chiral tartrate surface were used to construct different chiral systems on the Ti-O film.The chiral system was screened.Fibrinogen degeneration and platelet adhesion were used to examine the chiral surface of blood compatibility.In the selenocystamine molecule,the di-selenium bond has the ability to catalyze the release of nitric oxide from the endogenous nitric oxide donor.Therefore,the selenocystamine was substituted with hexamethylenediamine and the catalytic activity center was introduced into the secondary surface of the material.The effects of different chiral tartaric acid on the release of nitric oxide from the subchromic selenocystine-catalyzed donor and the effects on the adhesion and activation of platelets were investigated by grafting chiral tartaric acid on the surface of the material.X ray photoelectron spectroscopy(XPS)and water contact angle measurement(WCA)were used to modify samples,the results showed that the surface immobilied on polydopamine newly appeared Nls peak,and Ti2p peak of Ti-O membrane was completely covered,that polydopamine film was successfully prepared.The ratio of N:C of samples increased because of the introduction of a large number of amino grafting showed that hexanediamine was successfully prepared,the ratio of O:C ofsamples were increased which showed that the chiral tartaric acid and chiral sodium tartrate were grafted successfully.The water contact angle of the surface which grafted with series of chiral molecules almost no change indicating that WCA does not affect the surface hydrophobicity of chiral material surface.QCM-D results directly demonstrated that the number of L-tartaric acid and D-tartaric acid grafted on the surface of the sample was the same.While the amount of fibrinogen adsorption and bovine serum albumin adsorption of samples which grafted D-tartaric acid surface were obviously higher than those of samples which grafted L-tartaric acid.Although fibrinogen and bovine serum albumin adsorption experiments showed the D-tartaric acid samples had more adsorption of plasma protein and showed better affinity,which indicated that surface chirality could not be neglected influences.For samples grafted tartaric acid sodium,more fibrinogen and albumin adsorpted on D-surface,and the difference of these two proteins significantly decreased compared to those of samples grafted chiral tartaric acid.Although the amount of fibrinogen in the D-tartaric acid sample was higher than that of the L-tartaric acid sample,the degree of fibrinogen degeneration on the surface of the D-tartaric acid sample was lower than that of the L-tartaric acid sample surface.In the subsequent platelet adhesion and activation experiments,D-tartaric acid also showed better anti-platelet adhesion and activation ability.In order to further study the effect of chirality on the ability of catalyzing donor to release nitric oxide,selenocystine was used to instead of hexamethylenediamine to introduce catalytic center on the secondary surface,which could catalyze donor to release NO.The L-/D-tartaric acid were grafted to the surface to introduce chiral elements on the surface.The results of XPS showed that the Se element appeared on the surface of the material after the selenocystine was grafted onto the polydopamine,and the selenium content of the samples modified by different chiral tartaric acid molecules was equal,which was about 0.5%,the rate of samples grafted D-tartaric acid catalyzed endogenous release of NO donor was 1.0×10-100mol/cm2,the rate of samples grafted L-tartaric acid catalyzed endogenous release of NO donor was 0.7×10-10mol/cm2,indicating that the immobilized D-tartaric acid samples had better catalytic ability to release NO from endogenous donors.Platelet adhesion experimental results show that in the plasma without addition of endogenous nitric oxide donor,the amount of platelet adhesion from samples which deposited polydopamine was maximum,much less platelet adhered on samples immobilized D-tartaric acid than samples grafted L-tartaric acid samples,Ti-O samples had best blood compatibility.When donors were added in plasma,much less platelet adhered on sample which could release NO,and the number of platelets adhered to the surface of the immobilized D-tartaric acid sample was the least,which was significantly lower than that of the surface immobilized L-tartaric acid sample and the surface of the sample was only fixed with selenocystine.