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ABSTRACT: A phosphorylcholine-like silane coupling agent bearing zwitterionic molecular structure was synthesized and studied. The chemical structure of this silane coupling agent was characterized by FTIR, 1H NMR and 31P NMR. The zwitterionic structure was successfully constructed onto the surface of silicon as a self-assembled layer (SAL). Static water contact angle, and atomic force microscopy (AFM) were used to investigate the wettability and surface topography of the modified silicon surfaces. Static water contact angle results indicated that the hydrophilicity of the surfaces could be effectively improved by the modification with this zwitterionic silane coupling agent. The changes of the topography and water contact angle of the modified surfaces with different incubation periods in PBS solution were also measured to evaluate the stability of the SALs. Blood compatibility of the modified surfaces were evaluated by testing the full-blood activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT), as well as by observing the adhered blood platelets onto the surface. The modified surfaces showed prolonged clotting time and fewer adherent platelets, revealing that the blood compatibility was evidently improved by the modification using this zwitterionic silane.
ACS Applied Materials & Interfaces 10/2010; 2(10):2781-8. · 4.53 Impact Factor
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ABSTRACT: A biomacromolecular layer-by-layer coating process of chitosan/heparin onto a coronary stent is designed for the acceleration of the re-endothelialization and healing process after coronary stent deployment. The results of in vitro culturing of porcine iliac artery endothelial cells as well as the measurements of the APTT, PT and TT supported the rationale that the combination of chitosan and heparin could bring both endothelial cell compatibility and haemocompatibility to the stent surface. A porcine coronary injury model and arteriovenous shunt model were used for the further evaluation of the application of this kind of surface-modified stainless steel stent in vivo. The final results proved that this facile coating approach could significantly promote re-endothelialization and was safer compared with bare metal stents for its much improved anticoagulation property.
Biomaterials 02/2009; 30(12):2276-83. · 7.40 Impact Factor
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ABSTRACT: In this study, the synthesis, characterization, and properties of a novel biodegradable polymer with improved hemocompatibility were introduced. It was synthesized by end-capping poly-ε-caprolactone (PCL) with phosphorylcholine (PC) groups. The polyester backbone provided the mechanical stability and biodegradability, while the PC-end groups improved its hemocompatibility. The obtained polymer was characterized using 1H NMR, 31P NMR, FTIR, and GPC, its crystallization behavior was studied by DSC. Compared with original PCL, the resulting polymer (PC-PCL) showed a lower crystallization capability and a faster degradation rate in PBS. The degradation rate of the polymer blends of PCL/PC-PCL increased with increasing PC-PCL content. The results of water contact angle measurements revealed a more hydrophilic surface property of PC-PCL than neat PCL. The hemocompatibility of PC-PCL was estimated using rabbit platelet-rich plasma, a better resistance to platelet adhesion and activation was observed. During the human blood plasma contacting process, PC-PCL showed a prolonged activated partial thromboplastin time over neat PCL. Material–cell interaction was evaluated with human umbilical vein endothelial cell, the result indicated that PC-PCL may to some extent have an antihyperplasia property, compared with neat PCL. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 989–997, 2007
Journal of Applied Polymer Science 01/2007; 103(2):989 - 997. · 1.29 Impact Factor
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ABSTRACT: Surface immobilization of poly(ethylene glycol) (PEG) is an effective method to produce a material surface with protein repulsive property. This property could be made permanent by using covalent grafting of the PEG molecules onto material surfaces. In this study, self-assembled monolayers (SAMs) of PEG on silicon-containing materials (silicon chip and glassplate) were obtained through a one-step coating procedure of one kind of silanated PEG molecules made through the reaction between monomethoxy PEG and 3-isocyanatopropyltriethoxysilane. Atomic force microscopy (AFM) and water static contact angle measurement were employed to investigate the surface topography and wettability of the PEGylated material surfaces. The changes in the topography and the water contact angle of the surfaces with time of incubation in PBS solution were also measured. The results revealed that stable and uniform self-assembled monolayers of PEG could be formed on silicon or glass surfaces by simply soaking the substrates in the solution of silanated PEGs. The covalent coupling of PEGs to the substrates was also confirmed. In order to evaluate the stability of the SAMs, blood compatibility of the modified glassplate surface was evaluated by measuring full blood activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT), as well as by scanning electron microscopy (SEM) analysis of the appearance of adherence and denaturation of blood platelets onto the glassplate. The silanated PEGs were shown to have good effect on the protein-repulsion as well as haemocompatibility of the substrates.
Applied Surface Science 255(15):6771-6780. · 2.10 Impact Factor
