等离子体聚合沉积聚烯丙胺薄膜改性聚酯及体外血小板粘附研究

采用脉冲和连续波方式沉积等离子体聚烯丙胺薄膜改性聚酯(PET)材料表面,并进一步在等离子体聚烯丙胺薄膜表面固定肝素分子.利用衰减全反射红外光谱、X射线光电子能谱和接触角测试等离子体聚烯丙胺薄膜的元素成分、组成和表面能,采用对三氟甲基苯甲醛衍生法和甲苯胺蓝法分别检测了等离子体聚烯丙胺薄膜表面的伯胺基浓度和固定肝素分子的聚烯丙胺薄膜表面的肝素浓度.实验结果表明,脉冲等离子体聚合薄膜PPAa-P表面的伯胺基浓度为1.4%,而连续波等离子体聚合薄膜PPAa-C表面伯胺基浓度只有0.71%.等离子体聚烯丙胺薄膜改性的PET的表面能增加,其中PPAa-P改性的PET表面的表面能的极性分量增加较大.脉冲等离子体聚烯丙胺薄膜表面固定的肝素浓度为4.07μg/cm2,为连续波等离子体聚烯丙胺薄膜表面固定肝素浓度2.23μg/cm2的1.8倍.体外血小板粘附实验结果表明,表面肝素化的PET表面有较低数量的血小板粘附和激活,尤其是在固定肝素分子的脉冲等离子体聚烯丙胺薄膜改性的PET表面表现出更好的抗凝血性.     

等离子体聚合沉积聚烯丙胺薄膜改性医用不锈钢及内皮细胞粘附行为研究

采用等离子体聚合沉积方法,通过调控占空比参数,在医用不锈钢表面合成含有伯胺基的聚烯丙胺薄膜,并进一步在聚烯丙胺薄膜表面固定了明胶分子.漫反射傅立叶红外光谱和X射线光电子能谱的分析结果表明聚烯丙胺薄膜表面含有伯胺基团,明胶分子有效地固定到了聚烯丙胺薄膜表面.静态接触角测试结果表明固定了明胶分子的聚烯丙胺薄膜表现出较好的亲水性,具有较高的表面能.体外内皮细胞粘附实验及Alamar Blue评价结果表明固定了明胶分子的聚烯丙胺薄膜表现出良好的促内皮细胞粘附性能,且固定明胶分子的脉冲等离子体聚烯丙胺薄膜表面表现出更高的内皮细胞活性.     

构筑生物分子微图案的研究进展

随着微加工技术的发展,在材料表面构筑功能化的纳微米级图案越来越成为关注的热点。在生物科学领域,光刻蚀、微接触印刷和蘸笔纳米平板印刷等微图案技术被广泛应用并实现了生物分子在几十纳米微区域上的固定。生物分子在微纳米区域内的成功固定大大推动了生物微分析、生物芯片、生物微器件等生物技术及相关领域的发展。本文从分析生物分子与材料表面的相互作用入手,较为系统地评述了构筑生物分子微图案的几种重要方法,并对生物分子微图案技术的发展做了展望。     

氨等离子体离子注入改性Ti-O薄膜表面

在Ti-O薄膜表面固定粘连可以使其内皮化。然而欲在Ti-O薄膜表面实现生物分子固定，必须对Ti-O薄膜表面进行活化改性，比如引入具有反应性的官能团。采用非平衡磁控溅射设备制备了Ti-O薄膜，随后用等离子体浸没离子注入（PⅢ）技术对Ti-O薄膜表面进行等离子体活化改性，处理气体为氨气。并分别用扫描电子显微镜（SEM）、X射线光电子能谱（XPS）对注入后的样品表面形貌、表面成分进行分析。结果表明，有一定量的氨基被引入到材料表面。     

基于等离子体技术改性纺织材料的研究进展

改性可改善纺织材料性能或赋予其新的性能.改性方法主要包括生物改性法、化学改性法和物理改性法.等离子体技术是物理改性法中的典型技术,主要基于电离产生的等离子体来实现各种改性目的.近年来,等离子体技术已成为一个非常活跃、发展迅速的研究领域,在纺织材料的表面改性中占有重要地位.相对于其他改性方法而言,等离子体技术具有化学药品使用少、污染小、可操作性强等优势.通过等离子体在材料表面的作用可实现材料改性而不影响材料的内部结构.基于等离子体技术处理纺织材料的研究主要集中在以下四个方面:(1)清洁效果;(2)改变表面形态;(3)引入自由基;(4)等离子体聚合.低温等离子体对材料的损伤较小,是目前纺织材料改性中应用较广泛的等离子体技术.通过等离子体技术的刻蚀活化、自由基改性、聚合覆膜三种途径可提升纺织材料的润湿性、耐摩擦性、生物相容性及可染色性能,还能赋予纺织材料抗菌、自清洁以及自修复等功能,从而提升纺织品的应用价值,拓展其应用范围.本文简述了等离子体技术的分类,总结了当前等离子体技术的发展现状,重点综述了等离子体技术在纺织材料领域的应用,详细阐述了基于等离子体技术对纺织纤维、织物和纤维膜进行改性的研究进展.最后,基于以上综述结果,对等离子体技术在纺织材料领域的研究前景进行了展望.     

基于局域表面等离子体共振效应生物传感器的制备方法及应用

金属纳米颗粒表现出来的局域表面等离子体共振效应被广泛应用于生物传感器领域.综述了局域表面等离子体共振效应的基本原理,对比了局域表面等离子体和表面等离子体的异同,详细介绍了胶体化学平板印刷术、电子束光刻法、聚焦离子束光刻法、纳米球光刻术等多种金属纳米颗粒阵列和图形制备技术、特点及应用,分析了局域表面等离子体共振生物传感器的应用前景、现存问题及其解决途径.     

用于食品安全检测的便携式表面等离子体共振生物传感器

针对食品安全检测,构建了一种角度扫描型便携式表面等离子体共振生物传感器。详细介绍了光学系统、硬件电路及软件设计。并以盐酸克伦特罗(瘦肉精的一种)为检测样品,通过在传感器芯片固定生物探针,对浓度分别为2 mg/L、4 mg/L、8 mg/L、16 mg/L和32 mg/L的盐酸克伦特罗抗体进行了连续检测实验。实验结果符合生物分子免疫反应规律,证明了该装置的可行性。该装置便携、易操作,在食品安全检测领域具有广泛应用前景。     

常压等离子体在尼龙染色中的应用分析

等离子体是一种优良的导电体,在印染工业中,等离子体印染设备通过放电能使周围气体分子吸收电能形成等离子体,其高能粒子通过辐射、离子流、中性分子流撞击纤维和高分子材料表面,引起材料表面的一系列物理、化学改性,是一种全新的全新制造手段。常压等离子体处理技术避免了低温等离子体和低压等离子体技术存在的技术缺陷,逐渐在工业印染中得到重视。本文对常压等离子体在尼龙染色中的应用进行了分析,结果发现该技术能有效提高尼龙纤维的染色性能,且有效解决了污染问题,具有良好的经济和社会价值。     

光纤传感器在生物医学中的应用进展

光纤在医学和生物学中得到了广泛的应用,从光管道和压力传感器到复杂的化学传感器都与光纤有关.相干光纤束可用于内窥镜成像,而单光纤可用于近红外分层成像和光学相干分层成像.采用光纤还能方便地将光辐射传输到组织内,以激活靶标化学治疗药物.利用平面光纤光导将光波传输到测定部位的化学传感技术可以进行光度和荧光分析.光纤化学传感器还具有表面分子识别位点或化学反应部位,可用于特定分子的检测.这些化学传感器基于表面等离子体共振、干涉、光谱测量或荧光测量等原理.酶的生物识别或抗原抗体结合使光纤传感器可以获得高的特异性.近年来,测定的靶标分子的范围已从简单的气体分子和离子发展到了DNA等大分子.     

利用微型生物光学传感器的竞争免疫检测法检测牛奶中氨苄青霉素

利用微型表面等离子体共振的生物传感器测量了残留在牛奶中的氨苄青霉素的浓度.采用竞争抑制试验的方法,即先将定量的单克隆抗氨苄青霉素抗体（3H295）和含氨苄青霉素的牛奶样品混合,样品中氨苄青霉素即与抗体结合,然后将该混合样品通入传感器表面,传感器的表面共价固定了氨苄青霉素分子,通过生物特异相互作用分析,检测样品中剩余的抗体,从而得到氨苄青霉素的浓度.样品的测量时间为10min,最低检测限为2.5 ng/mL,低于欧盟标准4 ng/mL.该检测方法的测量时间短、重复性好,批间测量的变异系数为5.4%,表明该方法能满足实际测量要求.     

Molecular modeling of biomaterial surfaces

Molecular modeling has become widely recognized and accepted as an extremely valuable research tool for understanding and predicting molecular behavior. Recently reported papers utilizing molecular modeling to address biomaterial surface issues have centered upon the design of surfaces that are either resistant to protein adsorption or that specifically bind targeted biomolecules. Other applications include investigations of biomaterials and biological materials surface structure, surface hydrolysis and tribological behavior.     

Current trends in biomaterial surface functionalization—nitrogen-containing plasma assisted processes with enhanced selectivity

Low-pressure gas-discharge plasmas are widely used for polymer surface functionalization on industrial scale. For biomaterial applications, the density and selectivity of the functionalization are of particular importance, because functional groups control the immobilization of biomolecules. Therefore, surface modification of biomaterials is a challenging task for low-pressure plasma technique. Plasma processes have been successfully applied to various polymer types in order to generate multifunctional surfaces. This paper discusses the present state and the prospects of non-coating plasma processes to generate mono functional surfaces of controlled amino group density. Such surfaces appear most desirable for many applications. The results of various microwave- and radio-frequency- excited plasma processes reported in the literature are reviewed and compared to a sequence of experiments that was conducted in a UHV reaction environment. Non-thermal plasmas are especially well suited for thermally damageable polymers. The effect of hydrogen admixture to discharges in nitrogen and ammonia is discussed in detail. The optimization of process parameters lead to highly selective amino functionalization of high density. The selectivity reached 100% -NH₂/N at a surface density of amino groups of 3% -NH₂/C.     

Control of fibronectin displacement on polymer substrates to influence endothelial cell behaviour

Thin layered biomaterial surfaces of maleic anhydride copolymers are provided as a versatile platform for biomaterial applications. The provided comonomers define the character of the surface and its behaviour towards biomolecules and biosystems, such as proteins and cells. The kinetics of adsorption, desorption, and exchange of fibronectin and human serum albumin were investigated on different copolymer surfaces. Two different species of adsorbed proteins were found, a fast and a slow desorbing one. Furthermore, the exchange process depends on the kind of pre-adsorbed protein and the kind of exchange protein, as well as of the hydrophobicity of the copolymer surface. In this context adhesion, proliferation, and differentiation of endothelial cells from the umbilical cord vein onto fibronectin pre-coated surfaces were studied. Strong correlation between fibronectin exchange characteristics and the formation of focal adhesions, reorganisation of fibronectin, and generation of vascular-like structures by the cells was observed.     

低温等离子体技术在生物材料表面改性中的应用

综述了低温等离子体技术在生物材料表面改性中的应用.概述了低温等离子体分类、特征及其与生物材料表面作用的机理;介绍了低温等离子体聚合、低温等离子体处理、低温等离子体接枝聚合对生物材料表面改性的原理以及它们在生物材料领域中的最新应用进展和应用前景.     

In situ Endothelialization: Bioengineering Considerations to Translation

Improving patency rates of current cardiovascular implants remains a major challenge. It is widely accepted that regeneration of a healthy endothelium layer on biomaterials could yield the perfect blood‐contacting surface. Earlier efforts in pre‐seeding endothelial cells in vitro demonstrated success in enhancing patency, but translation to the clinic is largely hampered due to its impracticality. In situ endothelialization, which aims to create biomaterial surfaces capable of self‐endothelializing upon implantation, appears to be an extremely promising solution, particularly with the utilization of endothelial progenitor cells (EPCs). Nevertheless, controlling cell behavior in situ using immobilized biomolecules or physical patterning can be complex, thus warranting careful consideration. This review aims to provide valuable insight into the rationale and recent developments in biomaterial strategies to enhance in situ endothelialization. In particular, a discussion on the important bio‐/nanoengineering considerations and lessons learnt from clinical trials are presented to aid the future translation of this exciting paradigm.     

Plasma-based surface modification of polystyrene microtiter plates for covalent immobilization of biomolecules

In recent years, polymer surfaces have become increasingly popular for biomolecule attachment because of their relatively low cost and desirable bulk physicochemical characteristics. However, the chemical inertness of some polymer surfaces poses an obstacle to more expansive implementation of polymer materials in bioanalytical applications. We describe use of argon plasma to generate reactive hydroxyl moieties at the surface of polystyrene microtiter plates. The plates are then selectively functionalized with silanes and cross-linkers suitable for the covalent immobilization of biomolecules. This plasma-based method for microtiter plate functionalization was evaluated after each step by X-ray photoelectron spectroscopy, water contact angle analysis, atomic force microscopy, and bioimmobilization efficacy. We further demonstrate that the plasma treatment followed by silane derivatization supports direct, covalent immobilization of biomolecules on microtiter plates and thus overcomes challenging issues typically associated with simple physisorption. Importantly, biomolecules covalently immobilized onto microtiter plates using this plasma-based method retained functionality and demonstrated attachment efficiency comparable to commercial preactivated microtiter plates.     

Clay: New Opportunities for Tissue Regeneration and Biomaterial Design

Seminal recent studies that have shed new light on the remarkable properties of clay interactions suggest unexplored opportunities for biomaterial design and regenerative medicine. Here, recent conceptual and technological developments in the science of clay interactions with biomolecules, polymers, and cells are examined, focusing on the implications for tissue engineering and regenerative strategies. Pioneering studies demonstrating the utility of clay for drug‐delivery and scaffold design are reviewed and areas for future research and development highlighted.     

Gold nanoparticle-coated biomaterial as SERS micro-probes

We report for the first time, on the utility of plant-based biomaterial as enhanced-Raman scattering probes. The bio-substrate used in this study are commonly found in plant extracts, and are cost-effective, mechanically robust, flexible and easily transportable. The probe was fabricated by coating the plant extract with gold nanoparticles and characterized. By employing a ‘single-touch contact’ method, we reveal the ability of these probes to detect routinely used Raman markers such as 2-napthalenethiol and rhodamine B, at nano-molar concentrations, in dry and liquid forms, respectively. Reproducibility of the signals with variation <5%, and the ability to detect biomolecules are demonstrated herein. We envision these bio-probes as potential candidates for enhanced Raman sensing in chemical, environmental, and archaeological applications. By further engineering the shape, morphology, and surface chemistry of these micro-probes, we foresee their utility as miniaturized, natural SERS substrates.     

Surface and bioproperties of nanocrystalline diamond/amorphous carbon nanocomposite films

Nanocrystalline diamond/amorphous carbon (NCD/a-C) nanocomposite films have been deposited by microwave plasma chemical vapour deposition from CH₄/N₂ mixtures. In order to investigate their suitability as templates for the immobilization of biomolecules, e.g. for applications in biosensors, four differently prepared surfaces, namely as-grown, hydrogen plasma treated, oxygen plasma treated, and chemically treated with aqua regia, have been thoroughly characterized by methods such as XPS, TOF-SIMS, AFM, and contact angle measurements. In addition, in order to investigate the affinity of these surface to non-specific bonding of biomolecules, they have been exposed to bovine serum albumin (BSA). It turned out that already the as-grown surface is hydrogen terminated; the degree of the termination is even slightly improved by the hydrogen plasma treatment. Reaction with aqua regia, on the other hand, led to a partial destruction of the H-termination. The oxygen plasma treatment, finally, causes a termination by O and OH, rather than by carboxylic acid groups. In addition, an increase of sp² bonded carbon is observed. All surfaces were found to be susceptible to attachment of BSA proteins, but the coverage of the hydrogen terminated was lower than that of the O-terminated film. The highest BSA concentrations were found for the aqua regia sample where the H-termination has been removed partially. Finally, our results show that even minor surface contaminations have a great influence on the BSA coverage.     

丝素蛋白膜上vWf抗体的固定化及其体外抗凝血性能

用凝血因子的抗体对生物材料进行表面改性以提高其抗凝血性能。以丝素蛋白膜为基质，利用等离子体处理辅助的共价交联方法对vWf因子（von Wilebrand factor)抗体进行了固定化。用酶联免疫法和抗体过剩法对固定化效果进行了评价，固定化抗体的活性采用体外凝血时间（APPT，TT和PT）测定进行检测。结果显示，通过这种方法可以有效地将vWf抗体固定化，丝素蛋白膜固定化vWf抗体后，其抗凝血性能有了一定的改善。本研究结果拓宽了抗体固定化技术的应用范围，同时为抗凝血材料的设计提供了一种新的思路。