Papers by Keyword: Hemocompatibility

Abstract: Magnetron sputtering techniques was used to deposit TiN, TiO₂ single layer and TiN/TiO₂ multilayer coatings on 316L stainless steel (316L SS) substrates. The crystallinity, surface topography and roughness parameters of uncoated (316L SS) and coated specimens were examined. The anti adhesion and antibacterial behavior of S.aureus (gram (+) ve) and E.coli (gram (-) ve) strains on uncoated and coated substrates were determined by live/dead staining using epifluorescence microscopy. Results demonstrate that the coated samples undergo drastic reduction of bacterial adhesion and negligible effect of antimicrobial activity. Further, coated substrates exhibit less platelets activation than that of uncoated substrates.

Abstract: New types of ecologically benign surfactants with sugar as head groups (N-alkylglucosamides) have been described, namely, N-octylglucosamides (NOGA), N-dodecylglucosamides (NDGA), N-cetylglucosamides (NCGA). N-alkylglucosamides were characterized by Fourier transform infrared spectroscopy (FTIR) and ¹H Nuclear Magnetic Resonance (¹HNMR) respectively. N-alkylglucosamides was immobilized onto the surface of PPNWF by using Glycidyl methacrylate (GMA) as the linking agent. The chemical structure and composition of the modified PPNWF surface were analyzed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The surface properties were investigated by water contact angle. The water contact angles of the modified PPNWF decreased from 111° to 73°. The hemocompatibility of the modified PPNWF was evaluated by platelet adhesion. The number of platelets adhering to the modified surface was more dramatically reduced than that of the virgin surface. The results indicate that the modified surface of PPNWF by N-alkylglucosamides was a facile approach to construct biocompatible surface.

Abstract: The Paclitaxel-eluting stents (PTX) with biodegradable copolymer coating were studied in investigations. The polymer blend composition of PLGA (polylactic acid-co-glycolic acid) and PEG (poly ethylene glycol) have been applied as drug carrier and fabricated on the surface of 316L stainless steel stents by ultrasonic atomization spraying method. Were explored three doses: low-dose (~80μg per stent, 10 wt%), moderate-dose (~150μg per stent , 20 wt%), and high-dose (~220μg per stent , 30 wt%). The weight ratio of Paclitaxel to PLGA/PEG blends was 10:90, 20:80, and 30:70. Pre- and post-expansion surface morphologies of the Paclitaxel-eluting copolymer coating stents were examined by scanning electron microscopy (SEM). The quantitative analysis of Paclitaxel release in vitro and hemocompatibility by hemolysis ratio and dynamic clotting time measurement also were investigated.

Abstract: During nitriding treatment between 350°C and 550°C, the phase transformation sequence on the nitrided layers of the alloys was found to be γ → (γ + γ_N) → (γ + α+ CrN). The hemocompatibility test demonstrated the nitrided layer processed the excellent hemocompatibility properties. These results could be useful in further understanding the clinical mechanismsof thenitrided alloys, to develop as a potential biomedical material.

Abstract: Poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate) (poly(DMAPS)) zwitterionic brushes were grafted onto the polycarbonateurethane (PCU) surface to improve its hydrophilicity and hemocompatibility by Ultraviolet (UV) polymerization. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surface. DMAPS-grafted PCU films showed significantly high hydrophilicity owing to the high hydrophilic poly(DMAPS) zwitterionic brushes. The cytotoxicity tests revealed the sulfoammonium zwitterionic brushes modified PCU film had good cytocompatibility. In addition, the hemocompatibility of the modified PCU films was evaluated by hemolytic tests and platelet adhesion tests. The PCU films modified with zwitterionic brushes had a lower hemolytic index, showed effective resistance to platelet adhesion. Due to the fact that sulfoammonium zwitterionic brushes can improve the hemocompatibility of the PCU surface, this gives rise to its potential application as blood-contacting materials or devices.

Abstract: In this work, titanium oxide nanorod arrays were fabricated by using the hydrothermal method on fluorine-doped tin oxide (FTO) coated glass. The diameter of the nanorods could be controlled from 150 nm to 30 nm by changing the growth parameters. The surface morphology and the structure of the samples were characterized by SEM and XRD. The wetting properties were identified by contact angle measurement. Platelet attachment was investigated to evaluate the blood compatibility of the samples with different nanoscale topographies. Results show that the nanotopographical surfaces perform outstanding blood compatibility, and the adhering platelet decreased with the increasing diameter of the nanorods.

Abstract: In order to improve the hemocompatibility of polycarbonateurethane (PCU), the biomimetic phosphorylcholine (PC) group was introduced onto material surface. Brush structure having PC groups was formed by ultraviolet (UV) initiated polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve the hydrophilicity and hemocompatibility of PCU surfaces. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electrical microscopy (SEM) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surfaces. Compared with original PCU, the PC-grafted PCU surfaces showed significantly high hydrophilicity as indicating by low water contact angle. The hemocompatibility of the PC-grafted PCU surfaces was evaluated by platelet adhesion test. The PCU surfaces modified with phosphorylcholine zwitterionic brushes showed effective resistance to platelet adhesion and high hemocompatibility. These PC-grafted PCU materials will have potential application as blood-contacting materials or devices due to their good mechanical and hemocompatible properties.

Abstract: Hemocompatibility is a key property of biomaterials that come in contact with blood. Surface modification has shown great potential for improving the hemocompatibility of biomedical materials and devices. It has been improved that TiO₂ has excellent hemocompatibility. In this study, TiO₂ nanoparticles was added into polytetrafluorethylen (PTFE) resin in order to enhance hemocompatibility of the organic coating. The surface hydrophobicity of the coatings was characterized by contact angle measurement. Systematic evaluation of hemocompatibility, including platelet adhesion and blood clotting, proved that TiO₂ nanoparticles composite PTFE coating have better hemocompatibility. It is suggested that TiO₂ nano particles can improve hemocompatibility of organic coating due to its passive surface and chemical stability.

Abstract: In this paper, the TaCx coating with thickness around 1.2 μm was prepared by radio frequency magnetron sputtering technique on the 316L stainless steel substrate to improve its hemocompatibility. The structure and morphology of the coating were characterized by XRD and SEM. The XRD results indicated that TaCx, as a new species, appeared on the surface of the 316L stainless steel substrate. SEM images showed that the surface morphology of the TaCx coating was uniform and dense. The mechanical characteristics of the coating were measured by nanoindentation, giving a nanohardness of 13 GPa and a Young’s modulus of 210 GPa. The adhesion strength of the TaCx coating to 316L stainless steel depended on the sputtering bias voltages and increased for a higher bias voltage. The hemocompatibility of the TaCx coating, as evaluated by platelet adhesion tests, was compared to that of the bare 316L stainless steel. The results indicated that the hemocompatibility of 316L stainless steel with TaCx coating was significantly improved as compared to the original one.

Abstract: Low hemocompatibility is a major problem of biomaterials that come in contact with blood. Surface modification has become an important way to improve the hemocompatibility of medical implants and interventional devices. Recently, researchers attempt to investigate the possibility of silicon oxynitride (Si-N-O) films to be applied as novel coating of blood-contacting biomaterials. However, no detailed investigation has been conducted. In this study, our work was focused on the optimization of the hemocompatibility of Si-N-O films prepared on single-crystal silicon wafers by unbalance magnetron sputtering (UBMS). The structure and chemical composition of films were characterized by X-ray photoelectron spectrometry (XPS), and their physical chemistry property was characterized by contact angle measurements. Platelet adhesion test was performed to investigate the platelet adhesion and activation. Our results suggested that films composed of Si3N4 and SiOx (x<2) exhibited better hemocompatibility than low temperature isotropic pyrolitic carbon (LTIC) that is a common material used in blood-contacting implants. It was also revealed that the higher N/O ratio in films composed of Si3N4 and SiOx (x<2) was attributed to the lower platelet adhesion and activation, and the interaction of samples with plasma proteins was demonstrated to play an important role in the adhesion and activation of platelets.