卵磷脂/蒙脱土纳米中间体的制备及血液相容性研究

通过插层技术合成了卵磷脂/蒙脱土(PC/MMT)纳米中间体,利用XRD、FT-IR对合成的卵磷脂/蒙脱土纳米中间体进行了表征,结果表明卵磷脂已进入了蒙脱土层间,其层间距高达6.13nm;通过溶血试验和血浆复钙试验评价了PC/MMT纳米中间体的血液相容性,试验结果表明PC/MMT纳米中间体的溶血率<5%,符合生物医学材料的标准,复钙时间较长,有良好的血液相容性;预示了其在生物医药领域的潜在应用性.     

高吸水性纳米蒙脱土/聚丙烯酸复合材料的合成及其血液相容性

以部分中和的丙烯酸(AA)、钠基蒙脱土为原料制备了聚丙烯酸(PAA)及蒙脱土(MMT)/聚丙烯酸高吸水性树脂。采用FTIR、XRD和SEM等手段对其结构进行表征。通过溶血实验、 全血凝固时间实验和复钙化凝血时间实验对材料的血液相容性进行评价。结果表明:在聚合过程中,丙烯酸与蒙脱土片层中发生了化学反应;聚合后蒙脱土片层剥离,在复合材料中达到纳米级分散;所制备的聚丙烯酸以及蒙脱土/聚丙烯酸高吸水性树脂均具有良好的血液相容性。      

蒙脱土/聚合物纳米复合抗凝血膜的制备及其性能研究

利用溶液插层法合成了新型的蒙脱土-十八烷基二甲基-2-羟乙基溴化铵-肝素/硅橡胶抗凝血复合膜材料,并通过红外光谱、X射线衍射和机械性能测试对复合膜进行了表征.将纳米复合膜用于体外实验,通过观察溶血率、复钙化时间和血小板黏附实验来对其血液相容性进行了表征.研究结果表明蒙脱土/聚合物纳米复合膜具有较好的抗凝血性能.     

PLLA纳米纤维编织缝合线的制备及生物相容性研究

以PLLA为原料,采用静电纺丝和圆盘定向收集得到具有有序排列的纳米纤维束,并将其编织成线,得到PLLA纳米纤维缝合线.对新型可吸收PLLA缝线的微观形貌、血液相容性、细胞毒性进行了性能表征,并测试了其力学性能.结果表明,纳米纤维在一定的圆盘转速下表现出较好的定向性,力学性能良好.缝线在溶血试验中溶血率＜5%,符合医用材料的溶血要求.MTT实验结果表明缝线材料无细胞毒性,且显示出较高的增殖率,说明新型可吸收PLLA纳米纤维缝线具有良好的生物相容性和安全性.     

静电纺丝制备小直径血管支架及其血液相容性的研究

以甲酸为溶剂,将具有特定信号识别功能的RGD重组蛛丝蛋白(pNSR32)与聚己内酯(PCL)和壳聚糖(CS)共混,采用静电纺丝技术制备复合纳米纤维小直径血管支架,扫描电子显微镜(SEM)观察支架材料的微观结构,并通过溶血率、动态凝血时间、血小板黏附以及复钙化凝血时间实验评价支架材料的血液相容性.研究表明,(1) 所制备的pNSR32/PCL/CS复合纳米纤维支架内径为4mm,长度可达8cm,并且纤维连续,孔隙相通,孔隙率达85%以上,支架具有三维多孔网状结构,有利于种子细胞在支架上的黏附、增殖和迁移;(2)复合支架材料的溶血率＜5%,黏附的血小板少且不变形,复钙化凝血时间达293s,与单独PCL相比延长94s,说明该支架材料具有良好的血液相容性,有望成为一种新型的小直径组织工程血管支架.     

壳聚糖/PHB/PEG多元共混膜的制备与体外血液相容性研究

为了改善壳聚糖材料的血液相容性能,在醋酸体系中制备了壳聚糖(CTS)/聚-(R)-3-羟基丁酸酯(PHB)/聚乙二醇(PEG)的多元共混复合材料,复合膜材料的基本理化性质经FT-IR、广角X粉末衍射(WAXD)、SEM和水溶胀率测定表征,体外评价了CTS/PHB/PEG多元共混膜的血液相容性。结果显示,共混物组分间存在一定的化学作用,共混膜的结晶行为受CTS控制,PHB和PEG的加入对CTS材料的表面形貌及亲水性能有较大影响。三元共混膜较CTS在溶血率、复钙化时间、动态凝血曲线等血液相容性能方面有所改善,膜表面血小板粘附减少,表现出良好的抗凝血性能。     

壳聚糖-聚羟基丁酸酯共混膜的体外血液相容性评价

制备了壳聚糖(CTS)/聚(R)-3-羟基丁酸酯(PHB)二元系列膜,扫描电镜(SEM)分析检测其表面形貌.体外评价了不同比例共混复合物的溶血率、动态凝血、复钙化时间及血小板粘附.结果表明,二元共混膜较之原料壳聚糖相比,溶血率下降,复钙化时间延长,动态凝血曲线变化缓慢.SEM显示共混膜材料表面的血小板粘附现象明显少于壳聚糖.组成为C1B1的共混材料表现突出.通过与PHB简单共混的方法可以有效改善壳聚糖的血液相容性能.     

新型抗凝血生物材料的合成及其血液相容性的研究

以聚丙烯酰胺和肝素作为单体,通过溶液共混合成了侧链液晶聚丙烯酰胺,并与聚醚氨酯交联共混．制得了聚醚氨酯／液晶抗凝血复合膜材料,并通过IR、DSC、SEM对复合膜材料的液晶性进行了表征。将复合膜用于体外实验。通过观察溶血率和复钙化时间来对其血液相容性进行了表征。研究结果表明液晶复合膜具有较好的抗凝血性能。     

静电纺聚乳酸/姜黄素复合薄膜的制备及抗凝血研究

采用静电纺丝技术,以生物可降解聚乳酸(PLA)为载体制备了姜黄素含量分别为1％、3％和5％的纳米复合薄膜,利用接触角测量仪对不同纳米薄膜的润湿性能进行了测试,同时通过体外血小板粘附及部分凝血活酶时间(APTT)和凝血酶原时间(PT)实验评价纳米薄膜的血液相容性.研究表明:复合薄膜属于疏水性材料,可以满足医学应用;血液相...     

硫脲壳聚糖/蒙脱土纳米中间体的合成及其对大肠杆菌抑菌性能的研究

通过插层技术合成了硫脲壳聚糖/蒙脱土(Cts-TU/MMT)纳米中间体,利用XRD和FT-IR对合成的硫脲壳聚糖/蒙脱土纳米中间体进行了表征,结果表明硫脲壳聚糖已经进入了蒙脱土层间,其层间距达到3.529nm;通过抑菌动力学实验评价了硫脲壳聚糖/蒙脱土纳米中间体对大肠杆菌的抑菌性能,预示了其在生物医药领域的潜在应用性。     

Biocompatibility of novel carboxylated graphene oxide–glutamic acid complexes

The biocompatibility improvement of graphene oxide is crucial for biomedical applications. Herein, we propose to prepare carboxylated graphene oxide (GeneO–COOH) with glutamic acid (Glu) at different pH values. The complexes (GemeO–COOH/Glu) are characterized by FT-IR, XRD, TG, and Zeta potential. The results show that the complexes have close relation with pH value due to the acid-responsive Glu. It is demonstrated that GeneO–COOH complexes with Glu via amidation reaction in the basic domain. The blood compatibility of GeneO–COOH/Glu complexes is evaluated by hemolysis and recalcification test. The results show that the plasma recalcification time is prolonged greatly in the whole blood, and the hemolysis rates are less than 5 %. In a word, GeneO–COOH/Glu complexes are blood compatible at low concentration, which is potential for producing blood-contacting materials.     

Fabrication of thromboresistant multilayer thin film on plasma treated poly (vinyl chloride) surface

Layer-by-layer deposited anticoagulant multilayer films were prepared on ammonia plasma treated poly (vinyl chloride) (PVC). Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) and contact angle results revealed the presence of –NH₂ on the ammonia plasma treated PVC surfaces and the layer-by-layer self-assembly process. The stability of multilayer film was studied with the radio labeled method. The remainder bovine serum albumin (BSA) in cross-linked 5(heparin/BSA) multilayer films dipped in phosphate buffered saline (PBS, pH 7.4) was more than 90% in 40 days. The static platelet adhesion result indicated the anticoagulant multilayer films deposited on the plasma treated PVC reduced platelet adhesion drastically and no thrombus forming. The plasma recalcification time revealed that the multilayer modified surfaces greatly prolonged the plasma recalcification time. Such an easy processing and shape-independent method may have good potential for surface modification of cardiovascular devices.     

卵磷脂改性磁性碳纳米管的制备及生物相容性

采用生物活性两亲性分子卵磷脂(PC), 对制备的磁性碳纳米管(Fe₃O₄/CNTs)进行非共价修饰, 得到了内部为疏水端、外部为带电亲水基团的类膜结构包覆的改性复合材料Fe₃O₄/CNTs-PC。在溶液中带电基团通过溶剂化作用及亲水作用, 在复合材料表面形成水化层, 提高复合材料的自由水含量。在蛋白质吸附实验与复钙化凝血时间评价中, Fe₃O₄/CNTs-PC对蛋白质吸附量仅为0.1368 mg/mg, 复钙化凝血时间延长至324 s, 具有很好的生物相容性。     

Biocorrosion properties and blood and cell compatibility of pure iron as a biodegradable biomaterial

Biocorrosion properties and blood- and cell compatibility of pure iron were studied in comparison with 316L stainless steel and Mg–Mn–Zn magnesium alloy to reveal the possibility of pure iron as a biodegradable biomaterial. Both electrochemical and weight loss tests showed that pure iron showed a relatively high corrosion rate at the first several days and then decreased to a low level during the following immersion due to the formation of phosphates on the surface. However, the corrosion of pure iron did not cause significant increase in pH value to the solution. In comparison with 316L and Mg–Mn–Zn alloy, the pure iron exhibited biodegradable property in a moderate corrosion rate. Pure iron possessed similar dynamic blood clotting time, prothrombin time and plasma recalcification time to 316L and Mg–Mn–Zn alloy, but a lower hemolysis ratio and a significant lower number density of adhered platelets. MTT results revealed that the extract except the one with 25% 24 h extract actually displayed toxicity to cells and the toxicity increased with the increasing of the iron ion concentration and the incubation time. It was thought there should be an iron ion concentration threshold in the effect of iron ion on the cell toxicity.     

Sulfated hyaluronic acid as heparin-like material: physicochemical and biological characterization

Hyaluronic acid was partially sulfated and a polymer containing a precise number of sulfate groups for each repeating unit was prepared. The properties of this macromolecule in aqueous solution were studied at different pH levels by using potentiometric, viscosimetric techniques and were compared with that of the native hyaluronic acid, partially esterified hyaluronic acid and heparin. The influence of sulfate groups on the macromolecule is evident in the protonation constant and in the conformation of the polymer. This material exhibits an antithrombotic effect as evidenced by the lengthening of both the thrombin time and the whole blood clotting time. Moreover, the absence of hemolysis and the growth and shape of endothelial cells put in contact with the sulfated hyaluronic acid indicate that this polymer is a promising heparin-like compound.     

Cytocompatibility and Hemolysis of AZ31B Magnesium Alloy with Si-containing Coating

In the present study,a Si-containing coating was fabricated on AZ31 B Mg alloy.Cytocompatibility of the coated alloy was evaluated by both indirect and direct contact methods,respectively.Effects of a number of incubation variables on the sensitivity and reproducibility of the hemolysis test were also examined by using positively and negatively responding biomaterials.Cytocompatibility testing results indicated that cell condition,cell adherence,cell proliferation and extracellular matrix secretion of the coated alloy were improved compared with those of the uncoated alloy for different extraction and co-culture time.The hemolysis test suggested that hemolysis testing conditions were critical to determine the hemolysis of the alloy.It was also found that 1 day in vitro degradation of the uncoated AZ31 B alloy had no destructive effect on erythrocyte.As for the coated AZ31 B alloy at any time point,the hemolysis rate was much lower than 5%,the safe value for biomaterials.These in vitro experimental results indicate that the Si-containing coating is effective to improve the cytocompatibility and hemolysis behaviors of AZ31 B alloy during its degradation.     

The lyophilization of dispersed systems: influence of freezing process, freezing time, freezing temperature and RBCs concentration on RBCs hemolysis

In this work, we studied the influence of different parameters controlling cooling stage on biological dispersed system injury. The human red blood cell (RBCs) was chosen as work model. The study examined the influence of two freezing processes on RBCs hemolysis, one process producing big crystals, the other producing small crystals. Using both processes, we examined the effect of freezing temperature, freezing time, and RBCs concentration on injuries to RBCs. Freezing damage was assessed by the hematocrite measure before freezing and after thawing. The process producing a small number of big ice crystals (Pa) seems—in relation to the one producing a large number of small ice crystals (Pb)—to be less traumatic for the RBC, although the two are not statistically different. Freezing temperature and freezing time influence the preservation of RBCs. At 0 and -20°C there were high preservation and total hemolysis, respectively. At -5°C and -10°C, the RBC hemolysis depends on freezing temperature and freezing time. The RBCs hemolysis rates increases when freezing time increases and when freezing temperature decreases. The rates of RBCs preserved decreases with RBCs concentration some with either the freezing process used (Pa or Pb). More, an accentuation of the difference between the two used freezing processes on RBCs hemolysis was retrieved. The analysis of the conductivity evolution within the RBCs suspension frozen showed that the destruction of the RBCs is had essentially to the solution effects. When the crystallization eutectic takes place, the RBCs are already completely destroyed.