植入用高分子材料表面改性抗细菌粘附的研究进展

以植入材料为中心的感染导致的手术失败，严重限制了临床生物医用材料的应用。本文介绍了有关细菌在材料表面粘附的理论，材料表面自由能与细菌材料表面粘附的关系，并综述了近年来生物医用材料的表面改性的多种方法。     

高分子义眼材料表面的粗糙度及硬度

背景：高分子义眼材料的物理性能,如密度、硬度、机械强度等都影响义眼的加工精度,影响义眼表面的粗糙度,最终影响义眼戴用的舒适度。 目的：比较不同高分子义眼材料气泡生成率、硬度及表面粗糙度的差别。  方法：将7种品牌的高分子义眼材料分别制作为30 mm×30 mm×2 mm的试件,分别为A、B、C、D、E、F、G 7组,每组5个。按照由粗到细的原则,分别对每一试件其中一个面进行抛光,并测量两个面的表面粗糙度值,抛光面硬度值,计算材料内部气泡生成率。 结果与结论：A-G组的粗糙度值分别为(0.078±0.016),(0.074±0.019),(0.075±0.022),(0.066±0.020),(0.075±0.017),(0.068±0.015),(0.067±0.017) μm,各组间比较差异无显著性意义;硬度值分别为766.92±3.71,771.84±14.51,791.20 ±9.64,804.50±4.49,779.00±17.92,772.20±19.18,704.00±7.23,D组和G组与其余各组间比较差异有显著性意义(P < 0.05),D组和G组之间比较差异有显著性意义        (P < 0.05),其余各组间比较差异无显著性意义;气泡生成率分别为(8.87±0.29)%,(8.29±1.02)%,(6.94±0.43)%,(4.83±0.20)%,(7.59±0.19)%,(8.61±0.25)%,(4.89±0.17)%,D组和G组与其余各组间比较差异有显著性意义(P < 0.05),D组和G组间比较差异无显著性意义,其余各组间比较差异无显著性意义。在一定程度上说明气泡生成率越小,硬度越大,表面粗糙度越小。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

介入治疗导管表面润滑处理研究

介绍了一种用于介入治疗导管表面润滑处理的方法。对润滑涂层的作用原理、涂覆工艺等进行了论述，并讨论了用于润滑处理的聚合物、溶剂的选择及润滑处理后介入治疗导管表面摩擦系数的变化情况。通过生物安全性试验和临床试用，证明了本方法是安全可靠的。     

高分子材料的表面菌膜

背景：医疗器械尤其是高分子介入性导管引起的导管相关型感染是院内感染的主要途径之一,而导致人体感染的真正原因是器械或导管表面形成了菌膜。 目的：对菌膜的形成机制,影响菌膜形成和发展的因素以及当前抑制菌膜形成的常用方法进行综述。 方法：以“菌膜,生物膜,生物被膜”,“高分子,塑料,橡胶”和“biofilm,polymer,plastics,rubber”为检索词在medline、life sciences、Toxline plus、Derwent drug file、CBMDisc、CMCC等数据库和www.ncbi.nlm.nih.gov、www.uspto.gov、www.patent.com.cn等网站进行检索,得到相关国内外文献214篇。排除陈旧和内容类似文献,选择43篇文献进行综述。 结果与结论：目前对菌膜在高分子器械表面形成过程和形成机制已经基本阐述清晰,但迄今为止,菌膜的研究多集中从微生物学、医学、基因角度进行,对菌膜的防治也是直接从利用抗生素的抑制方面考虑,文章着重从材料角度探讨抑制菌膜的可能途径及其在临床应用的可能性。     

人工心脏用高分子材料的表面形态特征—扫描电镜观察报告

为了制造出表面光滑的高质量人工心脏血泵内表面，获得更好的抗血栓,性能作者对几种目前血泵研制中实验应用和准备应用的高分子材料的表面形态特征作扫描电镜观察，观察对象为PU－BD，Jm80,Pellethane2363-80A，和Pellethane2363-80AE等四种聚氨酯，以及Dow Corning3140硅橡胶和Silastic734硅橡胶，研究结果表明：四种聚氨脂材料表面光滑，但也有少量微缺陷，征的影响不明显，DowCOrning3140硅橡胶表面光滑，很少表面缺陷，但用DowCorning3140其中Pellethane材料更少些，干燥温度对聚氨酯表面形态特稀释溶液涂层的表面上缺陷明显增多，其中30％溶液涂层的表面奶粗糙，缺陷已呈蜂窝状，缺陷直径约2u,SIlastic734硅橡胶表面较粗糙，不宜用于血液接触面材料，本研究结果将对血泵研制的质量控制具有实用价值。     

介入治疗导管表面润滑处理研究

介绍了一种用于介入治疗导管表面润滑处理的方法。对润滑涂层的作用原理、涂覆工艺等进行了论述，并讨论了用于润滑处理的聚合物、溶剂的选择及润滑处理后介入治疗导管表面摩擦系数的变化情况。通过生物安全性试验和临床试用，证明了本方法是安全可靠的。     

光化学固定法--医用高分子材料表面改性的一种新方法

简述了医用高分子材料表面改性的一种新方法－－光化学固定法,指出该方法优于其它化学和物理的表面改性方法。简要叙述了光化学固定法的原理和光活性基团的分类,并对光化学固定法在医用高分子材料表面改性中的应用和前景作了介绍。     

人工软骨材料——聚乙烯醇水凝胶的研制

聚乙烯醇溶液于－２０℃左右的温度下冷冻６－１２ｈ,室温下颌化１－２ｈ,上述过程反复进行１－３次,然后对试样进行真空脱水处理,制得一种人工软骨材料－ＰＶＡ水凝胶。     

三嵌段高分子骨组织工程支架材料的表面多肽修饰与细胞粘附性研究

目的用甘氨酸-精氨酸-甘氨酸-天冬氨酸-丝氨酸-脯氨酸-半胱氨酸对三嵌段高分子骨组织工程支架材料进行表面修饰，并检测其细胞粘附性。方法利用异双官能交联剂将甘氨酸-精氨酸-甘氨酸-天冬氨酸-丝氨酸-脯氨酸-半胱氨酸多肽固定在聚丙交酯／乙交酯／天冬氨酸-聚乙二醇材料表面，并进行X线光电子分光镜检测和表面接触角测定；体外培养骨髓基质细胞，接种至表面修饰的材料上，测定细胞粘附力，并和未修饰材料对比。结果固定交联剂和多肽后X线光电子分光镜检测示硫元素的含量分别为0．3％和0．2％；硫元素的结合能是164eV和163．9eV；表面接触角为60．2±2．364度；细胞粘附力为（521．45±134．98）×10^-10牛顿。结论甘氨酸-精氨酸-甘氨酸-天冬氨酸-丝氨酸-脯氨酸-半胱氨酸能共价固定在聚丙交酯／乙交酯／天冬氨酸-聚乙二醇材料表面；多肽修饰后的材料能特异性的介导骨髓基质细胞粘附，增强其粘附力。     

介入导管材料的表面紫外光接枝润滑改性

研究了用紫外光直接引发亲水性单体在聚氨酯 ( PU)表面进行接枝反应。以改善 PU表面的润滑性。实验测定了单体浓度对接枝密度、吸水率、摩擦系数的影响 ,对不同反应方法得到的结果进行了比较 ,找到了获得最佳润滑表面的条件 ,并对接枝聚合物的表面进行了扫描电镜 ( SEM)观察。实验结果表明 :接枝亲水性单体可大大地改善聚氨酯表面的润滑性     

Release of Hydrophilic Drug from Biodegradable Polymer Blends

This paper reports on the release behavior of the drug lidocaine-HCl from a immiscible polymeric blend. Biodegradable polymer blends of poly(L-lactic acid)/poly(lactic-co-glycolic acid) (PLLA/PLGA) were loaded with lidocaine-HCl, and the release of lidocaine-HCl from these blends was monitored. It was found that the release profiles were significantly affected by the affinity and subsequent partitioning of the drug into one of the two phases in the blends. It was hypothesized that the hydrophilic lidocaine-HCl seems to have a tendency to reside in the PLGA component of the PLLA/PLGA blend. This resulted in a release very much controlled by the degradation of PLGA, even when PLLA is the major phase of the blend. A mathematical model was further employed to quantify the partitioning, as well as model the lidocaine-HCl release profiles of different blend compositions.     

Polymer of Controlled Chain Length Carrying Hydrophilic Galactose Moieties for Immobilization of DNA Probes

The synthesis and the “living” cationic polymerization of a new saccharidic monomer namely the 1,2 : 3,4‐di‐O‐isopropylidene‐6‐O‐(2‐vinyloxy ethyl)‐D ‐galactopyranose have been investigated. The monomer structure has been characterized by ¹H and ¹³C NMR, elemental analysis and mass spectrometry. It has been polymerized with acetaldehyde diethyl acetal/trimethylsilyl iodide as initiating system in presence of ZnCl₂ as co‐initiator. Macromolecules of controlled chain length (from 2 500 g·mol^–1 to 7 500 g·mol^–1) were obtained, bearing protected saccharidic moieties as side‐groups, and aldehyde as ω‐end‐groups which could be turned into amine ω‐end‐groups. Finally, the saccharidic residues were deprotected in order to perform the binding of DNA probes (oligonucleotides) onto the hydrophilic polymer chains through the anomeric site of the galactose moieties.     

Programmable Polymer Memory Device Based on Hydrophilic Polythiophene and Poly(ionic liquid) Electrolyte

A three‐terminal non‐volatile memory device with the configuration of an organic thin‐film transistor (OTFT) is constructed from two polymeric layers by using the conventional solution‐coating process. It consists of a hydrophilic polythiophene, regioregular poly(3‐carboxypentylthiophene) (P3CPT) as the active layer and a poly(ionic liquid), poly[1‐(4‐vinylbenzyl)‐3‐butyl imidazolium tetrafluoroborate] (PVBIT) as a polyelectrolyte layer. The conductivity of the polythiophene layer can be reversibly switched between high and low conductance states with “write” and “erase” bias at +3 and ?3 V, respectively. The retention time of the ON state is up to 1.6 × 10⁴ s and the write–read–erase–read switching is stable over 100 cycles. In addition, an instantaneous response and a fast switching speed are observed by simultaneous monitoring of both the “write” and “read” operations. All these results indicate that the device developed possesses potential applications as alternative solid‐state non‐volatile memory devices.

     

Double‐Hydrophilic Polymer Brushes: Synthesis and Application for Crystallization Modification of Calcium Carbonate

Summary: A water‐soluble diblock copolymer composed of poly(ethylene glycol) (PEG) and a cylindrical poly(acrylic acid) (PAA) brush is reported. It is prepared by a ‘grafting from’ approach using stepwise atom transfer radical polymerization combined with group transformation. Uniform molecular brushes, PEG₁₁₃‐b‐P(MA‐g‐PAA₂₆)₁₆₉, are thus prepared as indicated by atom force microscopy analysis. This PAA densely grafted polymer is used to induce the crystallization of calcium carbonate in aqueous solution. Different experimental conditions, fast mixing reactions and static diffusion methods, are applied to explore the effect of polymer brushes on the crystallization, which is characterized by scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis.

AFM image of the polymer brushes on mica and an SEM image of CaCO₃ particles prepared in its presence.     

Hydrophilic polymers derived from vitamin E

Vitamin E containing copolymers for biomedical applications was obtained by copolymerization reaction of vitamin E methacrylate (VEMA) with 2-hydroxyethyl methacrylate (HEMA), N,N-dimethyl acrylamide (DMA) or vinyl pyrrolidone (VP), in different experiments. High molecular weight copolymers prepared by free radical reactions initiated by azobisisobutironitrilo, AIBN, present a random distribution of vitamin E derivatives along the macromolecular chains, and the average composition depends on the initial composition of the reaction medium. The relative flexibility of the polymeric systems was analyzed measuring the glass transition temperature of copolymeric sequences and that of the pure alternating diad (Tg12) obtained by the application of the treatments proposed by Johnston and Barton to all the systems. Tg12 was higher than the average T of both homopolymers (Tg) for the VEMA-HEMA system, Tg12 was lower than Tg for the VEMA-DMA system and Tg12 was similar to Tg for the VEMA-VP system. VEMA-HEMA copolymers gave rise to hydrogels in water, acidic and alkaline media. VEMA-DMA copolymers gave rise to hydrogels in acidic medium and dissolved in water and alkaline medium. VEMA-VP copolymers were soluble in all media. The swelling of all the hydrogels fit a second order kinetics. A VEMA-HEMA hydrogel was selected for in vivo experiments in order to study the influence of vitamin E on the regeneration process of Achilles tendon. The polymeric derivatives of vitamin E stimulated the regenerative process as a consequence of the antiaging effect in the local area of application.     

Hydrophilic polymers derived from vitamin E

Vitamin E containing copolymers for biomedical applications were obtained by copolymerization reaction of vitamin E methacrylate (VEMA) with 2-hydroxyethyl methacrylate (HEMA), N,N-dimethyl acrylamide (DMA) or vinyl pyrrolidone (VP), in different experiments. High molecular weight copolymers prepared by free radical reactions initiated by azobisisobutironitrilo, AIBN, present a random distribution of vitamin E derivatives along the macromolecular chains, and the average composition depends on the initial composition of the reaction medium. The relative flexibility of the polymeric systems was analyzed measuring the glass transition temperature of copolymeric sequences and that of the pure alternating diad (Tg12) obtained by the application of the treatments proposed by Johnston and Barton to all the systems. Tg12 was higher than the average Tg of both homopolymers (Tg) for the VEMA-HEMA system, Tg12 was lower than Tg for the VEMA-DMA system and Tg12 was similar to Tg for the VEMA-VP system. VEMA-HEMA copolymers gave rise to hydrogels in water, acidic and alkaline media. VEMA-DMA copolymers gave rise to hydrogels in acidic medium and dissolved in water and alkaline medium. VEMA-VP copolymers were soluble in all media. The swelling of all the hydrogels fit a second-order kinetics. A VEMA-HEMA hydrogel was selected for in vivo experiments in order to study the influence of vitamin E on the regeneration process of Achilles tendon. The polymeric derivatives of vitamin E stimulated the regenerative process as a consequence of the antiaging effect in the local area of application.     

脂肪族聚酯类生物材料亲水性改性的研究进展

主要综述了丙交酯、乙交酯或ε-己内酯与亲水性的聚乙二醇、氨基酸、N-乙烯基吡咯烷酮和聚乙烯醇等亲水性物质进行嵌段或接枝共聚合反应,制备具有亲水性、温敏性或PH敏感性的共聚物.为缓控释药物、组织工程和体内植入器械提供组织相容性好、保持蛋白药物活性、无毒的生物医用材料.     

Hydrophilic molecularly imprinted poly(hydroxyethyl-methacrylate) polymers

Highly cross-linked 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) dimethacrylate with poly(ethylene glycol) of molecular weight 600 (PEG600DMA) were molecularly imprinted with hydrophilic templates glucose and proxyphylline using water as a solvent. Glucose-imprinted polymers showed increased recognitive capacity compared to nonimprinted polymers as well as increased glucose uptake compared to structurally similar galactose and methylglucopyranoside. Increasing glucose concentration in the imprinting mixture resulted in higher capacity and selective binding. Similar results were obtained for proxyphylline-imprinted P(HEMA-co-PEG600DMA) polymers, where the proxyphylline uptake was higher than structurally similar theophylline. Glucose-imprinted networks also showed diffusion coefficients on the order of 10(-6) cm2/s, conducive to applications in drug delivery and tissue engineering. This work showed that using pairs of hydrogen-bonding monomers and templates, selective, high-affinity sites could be created despite nonspecific binding.     

Synthesis and Properties of Hydrophilic Polymers, 10

Water‐soluble poly[(N‐maleoylglycine)‐co‐(hydroxyethyl methacrylate)] was employed for the separation of a series of metal ions in the aqueous phase using the liquid‐phase polymer‐based retention method. The method is based on the retention of inorganic ions by this polymer in conjunction with membrane filtration and subsequent separation of low‐molecular‐mass species from the polymer complex formed. It is shown that the polymer can bind several metal ions in aqueous solution at pH 3, 5, and 7, for example Cr(II), Co(II), Zn(II), Ni(II), Cu(II), Cd(II), Pb(II) inorganic ions. The interaction of the inorganic ions with the hydrophilic polymer was determined as a function of pH and filtration factor. The water‐soluble polymeric reagent with strong metal‐complexing properties was synthesized and used to separate complexed from non‐complexed ions in the homogeneous phase. The polymer exhibited high retention capability at pH 5 and 7. It was characterized by elemental analysis, FT‐IR, ¹H NMR, and ¹³C NMR spectroscopy, as well as by thermogravimetry. Additionally, viscosimetric measurements of the copolymer were performed at different pH values.

     

Micellar Structures of Hydrophilic/Lipophilic and Hydrophilic/Fluorophilic Poly(2‐oxazoline) Diblock Copolymers in Water

Amphiphilic poly(2‐alkyl‐2‐oxazoline) diblock copolymers of 2‐methyl‐2‐oxazoline (MOx) building the hydrophilic block and either 2‐nonyl‐2‐oxazoline (NOx) for the hydrophobic or 2‐(1H,1H′,2H,2H′‐perfluorohexyl)‐2‐oxazoline (FOx) for the fluorophilic block were synthesized by sequential living cationic polymerization. The polymer amphiphiles form core/shell micelles in aqueous solution as evidenced using small‐angle neutron scattering (SANS). Whereas the diblock copolymer micelles with a hydrophobic NOx_n block are spherical, the micelles with the fluorophilic FOx_n are slightly elongated, as observed by SANS and TEM. In water, the micelles with fluorophilic and lipophilic cores do not mix, but coexist.