碳纳米管/羟基磷灰石复合材料兔胫骨生物相容性研究

目的：探讨不同比例碳纳米管/羟基磷灰石纳米复合材料兔胫骨的生物相容性.方法：将碳纳米管含量为2%和3%的碳纳米管/羟基磷灰石复合材料置入兔右侧胫骨的缺损处,在1周～12周分别进行x线检查、组织学检查及分子生物学分析.结果：不同碳纳米管含量的复合材料均能诱导成骨,无排斥反应.X线片、组织学检查、分子生物学检查均无明显差别.结论：碳纳米管/羟基磷灰石材料有良好的骨相容性.     

纳米碳改性聚氨酯复合材料的表面抗凝血性能

研究纳米碳改性聚氨酯聚合材料表面的血液相容性。将经过表面处理的纳米碳分散到聚氨酯体系中，制成聚氨酯／纳米碳复合薄膜。通过血小板荧光标记人全血灌注实验和羊全血体外循环等实验，观察和测定血小板在材料表面的粘附作用以及血液中血红蛋白浓度、纤维蛋白原浓度的变化，探讨纳米碳对聚氨酯抗凝血性能的影响。实验结果显示聚氨酯／纳米碳表面血小板的粘附明显低于单纯聚氨酯对照组：体外循环4h后，血液中血红蛋白浓度、纤维蛋白原浓度的变化程度减小。表明纳米碳与聚氨酯的复合可以提高材料的血液相容性。     

医用聚氨酯生物相容性研究新进展

聚氨酯因有良好的生物相容性和机械性能，而被广泛用于生物医学领域，但聚氨酯长期植入人体内，也会引起机体的炎症反应，使材料发生老化降解现象。因而要进一步提高医用聚氨酯的生物相容性，使其与机体生理环境更加相容，不诱发或少诱发炎症反应，就要使材料表面更加生物化，可以维持蛋白的正常构象。本文综述了以仿生化为基础提高医用聚氨酯生物相容性的两种主要途径－表面内皮细胞化及仿生物膜结构（表面膦脂化），并总结了其实施方法及存在的问题。     

生物材料的生物相容性综合评价研究

生物相容性一直是生物材料应用于医疗器械的重点研究内容。但是目前国内外标准的评价体系尚未完全建立，影响了生物材料的研究。近年来趋于对生物材料进行综合评价，本文以复钙时间、血小板黏附以及血浆蛋白的量等实验为基础，结合层次分析法探讨了综合评价抗凝血生物材料的生物相容性的方法。     

聚氨酯的血液相容性评价

血液相容性是生物多材料研究领域里最受关注的问题之一，血液相容性是一个涉及血液和生物医学材料表面作用的复杂现象。影响因素繁多。对材料的血液相容性的测试和评价同样是一个复杂问题，涉及到多学科，多领域的技术和方法。本文以聚氨酯为例，对生物材料血液相容性的概念、生物医学材料表面和血液的相互作用以及评价方法作一综述。     

聚氨酯的血液相容性评价

血液相容性是生物材料研究领域里最受关注的问题之一。血液相容性是一个涉及血液和生物医学材料表面作用的复杂现象 ,影响因素繁多。对材料的血液相容性的测试和评价同样是一个复杂问题 ,涉及到多学科、多领域的技术和方法。本文以聚氨酯为例 ,对生物材料血液相容性的概念、生物医学材料表面和血液的相互作用以及评价方法作一综述     

多嵌段聚氨酯材料的表面结构与生物相容性

人工心脏隔膜用的聚氨酯材料至少应具有抗凝和耐挠曲的性能。通常提高聚氨酯的耐挠曲性多从调整其本体结构来考虑。由于聚氨酯的本体结构与表面结构不同,在挠曲过程中本体的相分离变化会影响表面软段的取向行为。因此为了知道挠曲对聚氨酯抗血凝性能的影响,作者从1983年起通过自制的耐疲劳试验代,利用XPS,FT-ATR-IR,WAXD,SAXS,SALS和血小板粘附试验等方法,测得在疲劳过程中聚氨酯表面的微相分离程度下降,聚醚软段含量减少,并导致其抗凝血性能下降。这样作者便把聚氨酯在反复变形过程中的本体形态,表面结构和生物相容性间的关系联系起来了。     

等离子体处理聚氨酯-胶原-硫酸软骨素复合材料的制备及性能评价

BACKGROUND: Polyurethane has excellent mechanical properties and perfect biocompatibility. But its hydrophobicity is not conductive to the adhesion and growth of cells, which limits its use as the scaffold of the skin. OBJECTIVE: To modify a polyurethane scaffold by plasma processing and crosslinking then to test its hydrophilic, mechanical properties and cytotoxicity in vitro. METHODS: Polyurethane porous materials were prepared into membranous materials by eletrospinning method and modified by CO2 and NH3 plasma. Then the plasma-modified polyurethane-collagen- chondroitin sulfate composite materials were prepared by crosslinking with collagen type I and chondroitin sulfate at the same time, which was named Group A. Polyurethane porous materials which were electrospun and modified by plasma were soaked into a mixed solution of collagen and chondroitin sulfate without crosslinking agent. After being air-dryed, the materials were prepared, named Group B. Polyurethane porous materials which were electrospun and modified by plasma were named Group C. Electrospun polyurethane porous materials without other treatments were named Group D. Then the morphology, hydrophilicity, mechanical property and in vitro cytotoxicity of the four groups were compared. RESULTS AND CONCLUSION: The plasma-modified polyurethane-collagen-chondroitin sulfate composite materials enjoy excellent fiber morphology, hydrophilicity and mechanical properties. It can also promote cell adhesion, proliferation and have no cytotoxicity.     

一种眼巩膜生物补片的制备及生物相容性研究

目的 制备一种适用于眼后巩膜加固术的新型生物补片,通过对其生物相容性进行研究,评价其生物安全性.方法 首先采用新鲜的牛心包经去除表面脂肪组织、脱细胞、扩孔和梳整后,与京尼平进行生物交联,制备出一种眼巩膜生物补片.然后进行体外细胞毒性试验、溶血试验、皮内反应试验、皮肤致敏试验、急性全身毒性试验和植入试验,通过检测细胞存活率、溶血率、皮内反应记分、皮肤致敏反应等级、毒性反应和植入刺激指数分析眼巩膜生物补片的生物相容性.结果 眼巩膜生物补片无细胞毒性反应、无潜在的动物皮内刺激和肌肉刺激作用、无皮肤致敏性和无急性全身毒性反应;溶血率符合要求.结论 通过扩孔和梳整工艺等技术所制备的眼巩膜生物补片具有良好的生物相容性,符合国家相关标准要求,为其在临床上眼后巩膜加固术中的安全应用提供参考.     

生物相容性评价的发展趋势

生物相容性一直是生物材料应用于医疗的中心话题。目前已被大多数人接受的观点是，生物材料的生物相容性不仅仅指没有细胞毒性作用，而且已包括其具有正面积极的生物功能。国际上检测生物材料的标准只规定了这种生物材料的最低应用标准，但并不保证能达到其最适功能。专家认为，生物相容性的检测在生物功能方面有很大的发展空间，并指出，将现代生物学技术融入生物材料的发展具有十分重要的意义。     

Comparative in vivo biocompatibility study of single- and multi-wall carbon nanotubes

Carbon nanotubes are expected to be of use in both genetic engineering and biomaterials engineering. In each of these potential areas of application, nanoparticles are introduced into a living organism either in the form of active biomolecule carriers or as a result of the degradation process of an implant. In the present study we focus on the in vivo behavior of two types of carbon nanotubes (single- and multi-wall nanotubes). Raman and Fourier transform infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry techniques are used to characterize the materials before introducing them into the living system. The nanotubes were implanted into the skeletal rat muscle. A comparative analysis of the tissue reaction to the presence of the two types of carbon nanotubes was made. It was observed that multi-wall carbon nanotubes were found to form large aggregates within the living tissue, while distinctly smaller particles consisting of single-wall nanotubes were easily phagocytosed by macrophages and transported to local lymph nodes.     

Mechanical properties and biocompatibility of functionalized carbon nanotubes/polypropylene composites

This study investigates the efficiency of carbon nanotubes (CNTs) as reinforcement for polypropylene (PP) for biocompatible application as a function of different surface functionalization of CNTs. PP composites were reinforced using various CNTs: single- and multi-walled carbon nanotubes (SWCNTs, MWCNTs), SWCNTs were covalently functionalized by plasma, for comparison, the MWCNTs were functionalized noncovalently. Different CNTs were incorporated into PP by solution blending. The type of CNTs and surface functionalization affects the mechanical and biocompatibility results significantly. Differences in nanostructure and the chemical compositions, number of functional groups, and structural defects for the CNTs may be the key factors affecting the mechanical properties and biocompatibility of PP nanocomposites compared to the neat PP. Finally, suitable CNTs and surface functionalization of CNTs were selected for making the PP/CNTs composites.     

Fatigue and biocompatibility properties of a poly(methyl methacrylate) bone cement with multi-walled carbon nanotubes

Composites of multi-walled carbon nanotubes (MWCNT) of varied functionality (unfunctionalised and carboxyl and amine functionalised) with polymethyl methacrylate (PMMA) were prepared for use as a bone cement. The MWCNT loadings ranged from 0.1 to 1.0 wt.%. The fatigue properties of these MWCNT-PMMA bone cements were characterised at MWCNT loading levels of 0.1 and 0.25 wt.% with the type and wt.% loading of MWCNT used having a strong influence on the number of cycles to failure. The morphology and degree of dispersion of the MWCNT in the PMMA matrix at different length scales were examined using field emission scanning electron microscopy. Improvements in the fatigue properties were attributed to the MWCNT arresting/retarding crack propagation through the cement through a bridging effect and hindering crack propagation. MWCNT agglomerates were evident within the cement microstructure and the degree of agglomeration was dependent on the level of loading and functionality of the MWCNT. The biocompatibility of the MWCNT-PMMA cements at MWCNT loading levels upto 1.0 wt.% was determined by means of established biological cell culture assays using MG-63 cells. Cell attachment after 4h was determined using the crystal violet staining assay. Cell viability was determined over 7 days in vitro using the standard colorimetric MTT assay. Confocal scanning laser microscopy and SEM analysis was also used to assess cell morphology on the various substrates.     

Preparation and evaluation of polyurethane surfaces containing immobilized plasminogen

Plasminogen has been immobilized onto a segmented polyurethane containing amino groups, using glutaraldehyde as coupling agent. It was also aspecifically adsorbed, for sake of comparison, onto polyurethane films containing different functional groups and, in particular, ε-amino caproic acid and lysine residues. The differently immobilized plasminogen has been converted to plasmin by activation with urokinase, and the percentage of active plasmin obtained for the various polymer films was determined using a tripeptide (S-2251) as a synthetic substrate. The biological behaviour of the differently treated polymer films has been evaluated in vitro by measurements of partial thromboplastin time (PTT) and platelet adhesion.     

低分子质量壳聚糖修饰多壁碳纳米管的制备及细胞毒性研究

目的 利用低分子质量壳聚糖(CS)制备可在水溶液中稳定分散的壳聚糖/多壁碳纳米管(CS/MWCNTs)材料,并观察其与人脐静脉内皮细胞(HUVEC)的相互作用.方法 以物理吸附法对MWCNTs进行CS修饰,利用透射电镜、纳米粒度及Zeta电位分析仪对其进行表征.将CS/MWCNT进行荧光标记,以不同浓度与细胞作用24 h,通过激光共聚焦显微镜观察细胞摄入情况,并检测细胞毒性及细胞内活性氧自由基含量.结果 当低分子质量CS与MWCNTs的质量比大于10∶1时,可很好地将MWCNTs进行分散,CS/MWCNTs可在水相中稳定存在.细胞摄入实验显示,进入细胞内的碳纳米管主要位于胞浆内.毒性检测结果显示,在较高质量浓度(10、20 μg/ml)时,CS分散后的MWCNTs毒性较小.而与2种碳纳米管(MWCNTs与CS/MWCNTs)作用的细胞内的活性氧含量均随着浓度升高而显著提高,差别无统计学意义(P＞0.05).结论 水溶性的CS/MWCNTs材料拥有极好的分散性,性状稳定,细胞毒性低,这对后期将其应用于以MWCNTs为载体的治疗研究具有重要意义.     

羧基化单壁碳纳米管的制备及其血液相容性研究

目的：本研究旨在对单壁碳纳米管（SWCNT）进行羧基化改性并对改性前后的SWCNT进行血液相容性研究。方法利用浓硫酸与浓硝酸(3：1,v/v)将SWCNT氧化成羧基化单壁碳纳米管(SWCNT-COOH),采用红外光谱仪（FTIR）、马尔文激光粒径仪进行材料表征。采用扫描电子显微镜（TEM）观察修饰前后的SWCNT对红细胞聚集和形貌的影响。采用血栓弹力图仪(TEG)检测修饰前后的SWCNT对凝血功能的影响。结果利用化学氧化法成功地将SWCNT表面进行羧基化处理。10 mg/ml的SWCNT-COOH引起红细胞聚集和形貌变化。0.01 mg/ml SWCNT和0.001 mg/ml SWCNT-COOH促进了凝血因子的活化。结论用浓硫酸和浓硝酸氧化法可有效地制备SWCNT-COOH。通过红细胞形态观察和凝血实验,揭示了SWCNT和SWCNT-COOH的血液相容性,为SWCNT-COOH的优化设计和生物医学应用提供了重要的依据。     

多孔聚乙烯醇/明胶软骨组织工程支架复合材料的制备及其生物相容性

背景：以明胶为基体制备的组织工程支架材料具有良好的生物相容性和生物降解性能,但存在力学性能低,降解速率难以控制的缺陷。 目的：制备一种软骨组织工程支架材料多孔聚乙烯醇/明胶复合物,并检测其理化性能和生物相容性。 方法：采用乳化发泡法制备聚乙烯醇/明胶多孔支架,并通过电镜分析、力学测试、皮下植入实验,检测材料孔径和孔隙率、IR光谱、力学性能和生物相容性。 结果与结论：多孔材料内部呈三维网状多孔结构,孔径均匀,有相似的孔隙率61.8%,含水率44.6%,抗拉强度为(5.01±0.03) MPa,抗压强度为(1.47±0.36) MPa,有较好的力学性能,IR光谱分析表明材料内部结构均匀。皮下植入后,炎症反应逐渐减轻,囊壁逐渐变薄,并趋于稳定,提示多孔聚乙烯醇/明胶支架材料具有较好的生物相容性和力学性能。     

Synthesis and in vitro biocompatibility of injectable polyurethane foam scaffolds

The development of therapeutics for orthopedic clinical indications exploiting minimally invasive surgical techniques has substantial benefits, especially for treatment of fragility fractures in the distal radius of osteoporotics and vertebral compression fractures. We have designed six formulations of injectable polyurethane foams to address these clinical indications. The polyurethanes were prepared by mixing two liquid components and injecting the reactive liquid mixture into a mold where it hardens in situ. Porous polyurethane foams were synthesized from lysine methyl ester diisocyanate, a poly(epsilon-caprolactone-co-glycolide) triol, a tertiary amine catalyst, anionic and non-ionic stabilizers, and a fatty acid pore opener. The rise time of the foams varied from 8-20 min. The porosity was approximately 95% and the pores varied in size from 100-1000 microm. The polyurethane foams supported attachment of viable (>95%) MG-63 cells under dynamic seeding conditions. We anticipate compelling opportunities will be available as a consequence of the favorable biological and physical properties of the injectable polyurethane foams.     

Enhanced biocompatibility and antibacterial property of polyurethane materials modified with citric acid and chitosan

Citric acid (CA) and chitosan (CS) were covalently immobilized on polyurethane (PU) materials to improve the biocompatibility and antibacterial property. The polyurethane pre-polymer with isocyanate group was synthesized by one pot method, and then grafted with citric acid, followed by blending with polyethersulfone (PES) to prepare the blend membrane by phase-inversion method so that chitosan can be grafted from the membrane via esterification and acylation reactions eventually. The native and modified membranes were characterized by attenuated total reflectance-Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurement, and tensile strength test. Protein adsorption, platelet adhesion, hemolysis assay, activated partial thromboplastin time, prothrombin time, thrombin time, and adsorption of Ca²⁺ were executed to evaluate the blood compatibility of the membranes decorated by CA and CS. Particularly, the antibacterial activities on the modified membranes were evaluated based on a vitro antibacterial test. It could be concluded that the modified membrane had good anticoagulant property and antibacterial property.     

In vitro biocompatibility assessment of sulfonated polyrotaxane-immobilized polyurethane surfaces

Sulfonated polyrotaxanes (PRx-SO(3)'s), in which sulfonated alpha-cyclodextrins (alpha-CDs) were threaded onto the poly(ethylene glycol) (PEG) segments in a PEG-b-poly(propylene glycol) (PPG)-b-PEG triblock copolymer (Pluronic) capped with benzyloxycarbonyl (Z)-L-phenylalanine (Z-L-Phe), were prepared as a novel surface-modifying biomaterial. Surface modification of the polyurethane (PU) was carried out by blending the PRx-SO(3)'s with a PU solution, followed by solution casting. The incorporated PRx-SO(3)'s led to the enhanced hydrophilicity by changing the surface properties of the PU matrix. Modified PUs showed the stable entrapment of the PRx-SO(3)'s with little extraction into water and enhanced mechanical properties after exposure to water compared to the PU control. The incorporated PRx-SO(3)'s repelled the proteins and kept them from closely approaching the surface areas, prevented platelet activation by thrombin, and effectively repelled bacteria. These results suggest that both the supramolecular structure of the polyrotaxanes and exposure of the sulfonated groups onto the surfaces contribute to these phenomena. Thus, surface modification with PRx-SO(3)'s is suggested to be useful for the fabrication of biocompatible medical devices.