Nanotechnology Application In The Field Of Anti-clotting Biological Materials

Blood compatibility of biomaterial has close relation to material surface properties, such as surface wettability, surface energy, interface tension and surface charge. It's a great task for researchers to deep investigate the interactions of biomaterial with blood and further recognize the surface modification mechanism of anticoagulation materials.In this paper, with the guidance of the bionic principle, we fabricated superhydrophobic surfaces by the method of nanotechnique, and then studyed the possible applications in the biomedical field. Polymer materials with different surface patterns here were fabricated by the techniques of template-based method, solvent-nonsolvent phase separation method and polymer phase separation method respectively. They were polystyrene (PS) films with parallel array nanotubes, polystyrene (PS) films with micro-nano-binary structured nanotubes, nanoparticle-structured polypropylene-e(PP) film and polypropylene/polyurethane (PU/PP) micro-and nano-papillary composite films. The scanning electron microscope (SEM) images were used to observe the surface topography of each film and the water contact angles of relevant patterns were tested. The results showed that the micro-and nano-surface patterns could improve the hydrophobicity of the materials effectively. Advantages and disadvantages of the three methods in preparation of biomaterial were also discussed respectively in this paper.Here, the interaction between blood and the films were analyzed systematically by biochemical tests, such as platelet and human whole blood adhesion tests.The investigations of the blood cell adhesion on the two kinds of PS nanotube films with different topographies suggested that the blood cell adhesion reduced with the increasing of materials hydrophobicity. Moreover, the micro-nano-binary structure on the materials surface can achieved the effect of anti-platelet and blood cell adhesion.The same conclusion had also been verified in blood compatibility experiments of the PP nanoparticle-structured films and PU/PP micro-and nano-papillary composite films.In summary, it's proved that all the three kinds of micro-and nano-structured surfaces in this paper could improve anticoagulation properties of the polymer films effectively without changing the basic chemical constituents of them.In addition, the systhesis of nanoparticles [PNIPAM-g-P(NIPAM-co-St) Nanoparticles, PNNS-NPs] and their biocompatibility had also been studied in this paper. The nanoparticles were characterized by the biophysical and chemical methods, such as scanning electron microscopy (SEM), water contact angle (WCA) measurement, Zeta potential, particle-size analysis, hemolysis test, in vitro coagulation time. The result indicated that the sizes of the PNNS-NPs are uniform with the average size of 134.6nm. The result of Zeta potential showd that the charge of PNNS-NPs is negative. Both activated partial thromboplastin time (APTT) and prothrombin time (PT) were prolonged remarkably, indicating that the PNNS-NPs were antithrombogenic and exhibit high anticoagulant activity.Besides, with the hemolysis test, we also get the same conclusion. In order to further evaluated the biosafety of PNNS-NPs, we also cultured HUVECs with PNNS-NPs, and the MTT (Methyl Thiazolyl Tetrazolium) test showed that PNNS-NPs were non-toxic to these cells. All experiments above indicated that the PNNS-NPs have good biocompatibility.