织构复合水凝胶体系的假说

生物软组织可视为具有多层次结构的织构复合水凝胶体系(TCHS)、以水凝胶复合元件(HCE)为基本的构件(CP),通过一定的组合、排列方式构筑一系列多层次结构的不同软组织。软组织中任何层次的结构单元既可视为织构复合水凝胶体系又可视为构件。任何层次的TCHS中,构件的结构及其组合排列方式决定着该层次单元的功能。以织构复合水凝胶体系的观点考察了真核细胞、角膜和骨骼肌的多层次结构。双层网络水凝胶、皮芯复合水凝胶纤维人工肌肉模型、时空匹配可降解细胞支架等研究成果初步地证明了提出织构复合水凝胶体系观点的合理性。     

织构复合水化体系的假说 第四报:水复合方式初探

背景:人体组织中的水分子和生物大分子结合形成水复合物.不同类型的大分子与水分子复合的方式也不同.目的:讨论水分子和生物大分子进行复合的基本方式.方法:提出了织构复合水化体系(TCHS)的理论假说.通过计算机检索相关文献,对这些问题展开讨论.结果与结论:根据水在水复合体中的作用特点,可以分类为如下4种复合方式.①表面复合:球状蛋白质分子或DNA分子表面形成水复合膜层.水膜层显示水分子运动速度和水化密度由表及里逐渐减弱.水复合膜确保大分子的几何形态和物理状态稳定,而且在TCHS形成中发挥重要作用.②溶胀复合:由于糖胺聚糖的强烈水合作用,水复合的蛋白聚糖发生溶胀,显示高黏度和水凝胶特性.它在结缔组织中发挥重要的力学贡献,如赋予软骨以强大的抗变形能力.③疏水复合:在疏水作用下磷脂分子经结构重排形成脂双分子层结构(生物膜).该亲水-疏水-亲水的"三明治"结构,有助于自身的力学稳定、与膜蛋白的结合、跨膜运输等.④缝隙复合:细胞内外大量存在着纳米尺度的狭窄空间,位于其中的水溶液因水分子发生重排而物性异常,如黏度增高、冰点下降等.缝隙复合和表面复合两者具有某些共性,前者可以看作是后者的一种特例.上述的分类方法不具有绝对的涵义.但是合理运用这些水复合方式将有助于研究织构复合水化体系的理论.     

织构复合水化体系的假说(第三报):人体中的纳米缝隙水

极为狭窄缝隙中的水(水溶液)往往显示反常的物性.在细胞内部的微管及其织构复合水化体系、核膜以及在细胞外部的质膜内褶和细胞连接粘连之处都可以发现许多纳米尺度(100-109 nm)缝隙空间.这些缝隙空间里充满着不同类型的体液(纳米缝隙水),包括细胞外液、细胞内液及其他液体.某些球状蛋白质分子的内部空隙中也会存在纳米缝隙水.人体组织中的纳米缝隙水显示异常的物性(黏度剧增、冰点剧降等).     

pH敏感壳聚糖-海藻酸钠复合水凝胶的溶胀特性及应用

目的：研究pH敏感性壳聚糖海藻酸钠水凝胶体系的溶胀特性及在药物缓释中的应用。方法：在温和条件下制备壳聚糖-海藻酸钠复合水凝胶颗粒，研究其在胃的pH环境(pH=1．4)和肠道pH环境(pH=7．4)的溶胀动力学并考察各种因素对凝胶溶胀性能的影响，利用该凝胶的特性制备酮洛芬微囊，测定其在人工胃液和人工肠液中的缓释效果。结果：该凝胶颗粒在pH=1．4的盐酸缓冲溶液中溶胀度较小，而在pH=7．4的磷酸盐缓冲溶液中溶胀度很大，用它制备的酮洛芬微囊具有明显的缓释效果。结论：讨论了壳聚糖浓度，海藻酸钠浓度，钙离子浓度对凝胶溶胀性能的显著影响以及利用这些特性制备的酮洛芬微囊的缓释效果。     

氧化型琼脂糖凝胶基片结合酶免疫反应的蛋白质分子微阵列

目的 研制适于常规免疫学检查的蛋白质分子微阵列。方法 利用分子组装技术,以琼脂糖凝胶为基质,于玻片表面制成自组装膜,经过碘酸钠氧化后再与戊二醛分子偶联,而成为具有双功能分子层的薄膜。基片表面衍生的醛基可与各类抗原（如重组多肽,磷脂和DNA）,辣根过氧化物酶及抗体分子中的氨基形成Schiff's碱共价连接。结果 基于上述原理,制作生物分子微阵列,优选出IgG分子的最佳点样浓度为100μg/ml,点样量以50nl为宜。通过不同的实验模式,成功地在基片表面建立了酶免疫检测体系,可敏感特异地检出抗原,抗体分子及酶与底物之间的相互作用。结论 该法最突出的优点在于减少了样本和试剂用量,可对多种自身抗体实施高通量的平行分析,以酶－度物（HRP－DAWB－H2O2）作为芯片信号显示系统,结果较为直观,具有较大的实用性和应用前景。     

pH敏感壳聚糖-海藻酸钠复合水凝胶的溶胀特性及应用

目的研究pH敏感性壳聚糖海藻酸钠水凝胶体系的溶胀特性及在药物缓释中的应用.方法在温和条件下制备壳聚糖-海藻酸钠复合水凝胶颗粒,研究其在胃的pH环境(pH=1.4)和肠道pH环境(pH=7.4)的溶胀动力学并考察各种因素对凝胶溶胀性能的影响,利用该凝胶的特性制备酮洛芬微囊,测定其在人工胃液和人工肠液中的缓释效果.结果该凝胶颗粒在pH=1.4的盐酸缓冲溶液中溶胀度较小,而在pH=7.4的磷酸盐缓冲溶液中溶胀度很大,用它制备的酮洛芬微囊具有明显的缓释效果.结论讨论了壳聚糖浓度,海藻酸钠浓度,钙离子浓度对凝胶溶胀性能的显著影响以及利用这些特性制备的酮洛芬微囊的缓释效果.     

复合水凝胶人工角膜裙边支架材料的生物相容性评价

背景:β-磷酸三钙/聚乙烯醇复合水凝胶具有高含水量、良好柔软性优点,有利于成纤细胞生长及胶原沉积,适用于做人工角膜裙边支架材料。目的:评价β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料的生物相容性。方法:①迟发型超敏反应:在豚鼠脊柱两侧皮内由头到尾分别注射A液(完全弗氏佐剂与生理盐水等体积混合液)、B液(β-磷酸三钙/聚乙烯醇复合水凝胶浸提液或生理盐水或2-巯基苯并噻唑)、C液(A液与B液等体积混合稳定性乳化剂),并进行局部诱导及激发。②急性全身性毒性实验:由昆明小鼠尾静脉分别注射生理盐水与β-磷酸三钙/聚乙烯醇复合水凝胶浸提液。③体外细胞毒性实验:分别以β-磷酸三钙/聚乙烯醇复合水凝胶浸提液、细胞培养液及含苯酚的细胞培养液培养MRC-5细胞。④皮内反应:在兔脊柱皮内分别注射β-磷酸三钙/聚乙烯醇复合水凝胶生理盐水(或芝麻油)浸提液、生理盐水及芝麻油。结果与结论:β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料的迟发型超敏反应分级为0-1级,急性全身毒性实验结果为正常无症状,体外细胞毒性均为0级或1级,皮内反应为极轻微。表明β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料生物相容性指标达到生物植入医用材料的要求。     

复合水凝胶人工角膜裙边支架材料的生物相容性评价

背景：β-磷酸三钙/聚乙烯醇复合水凝胶具有高含水量、良好柔软性优点,有利于成纤细胞生长及胶原沉积,适用于做人工角膜裙边支架材料。目的：评价β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料的生物相容性。方法：①迟发型超敏反应：在豚鼠脊柱两侧皮内由头到尾分别注射A液（完全弗氏佐剂与生理盐水等体积混合液）、B液（β-磷酸三钙/聚乙烯醇复合水凝胶浸提液或生理盐水或2-巯基苯并噻唑）、C液（A液与B液等体积混合稳定性乳化剂）,并进行局部诱导及激发。②急性全身性毒性实验：由昆明小鼠尾静脉分别注射生理盐水与β-磷酸三钙/聚乙烯醇复合水凝胶浸提液。③体外细胞毒性实验：分别以β-磷酸三钙/聚乙烯醇复合水凝胶浸提液、细胞培养液及含苯酚的细胞培养液培养MRC-5细胞。④皮内反应：在兔脊柱皮内分别注射β-磷酸三钙/聚乙烯醇复合水凝胶生理盐水（或芝麻油）浸提液、生理盐水及芝麻油。结果与结论：β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料的迟发型超敏反应分级为0-1级,急性全身毒性实验结果为正常无症状,体外细胞毒性均为0级或1级,皮内反应为极轻微。表明β-磷酸三钙/聚乙烯醇复合水凝胶人工角膜裙边支架材料生物相容性指标达到生物植入医用材料的要求。     

高分子水凝胶复合材料的分类学研究

目的 探讨以复合材料学方法所得高分子水凝胶的分类。方法 根据多尺度设计的观点将现有的研究结果进行综合和分析，并依据复合方式及其结构层次对水凝胶复合材料进行了分类。结果和结论 提出了复合水凝胶材料的一种分类体系，其中引入了分子间复合及织构复合等新概念。运用这些概念和方法有助于生物复合材料的研究。     

聚乙烯醇-海藻酸钙-透明质酸复合水凝胶材料的含水特性

背景：聚乙烯醇和海藻酸钠均为亲水性的聚合物，互溶性好，但其单独使用在材料的弹性和含水率等性能方面不理想。 目的：制备聚乙烯醇-海藻酸钠-透明质酸组织工程支架，分析不同重均分子质量和醇解度的聚乙烯醇、不同质量分数的海藻酸钠、不同用量的透明质酸对材料含水率和膨胀率的影响。 设计、时间及地点：对比观察实验，于2006—10／2008—03在广州暨南大学生物材料省重点实验室，教育部再生医学研究中心重点实验室完成。 材料：聚乙烯醇，Mw14500，61500，为BS Chemical Technology产品，聚乙烯醇，Mw 88000，95000，为ACROS ORGANICS产品，聚乙烯醇-124，Mw24000，为广州市医药公司产品，透明质酸为美国Sigma公司产品，NaOH、CaCl2、海藻酸钠为国产分析纯。 方法：将不同重均分子质量和醇解度的聚乙烯醇与不同质量分数的海藻酸钠、不同用量的透明质酸复合。 主要观察指标：测定其复合材料的含水率和膨胀率，用扫描电镜观察材料内部的组织形态。 结果：制备的聚乙烯醇-海藻酸钙-透明质酸复合材料平滑、柔韧，具有弹性。含水率为62．66％～86．64％，膨胀率为145．74％～324．45％。含水率和膨胀率随着聚乙烯醇重均分子质量和醇解度的增加而减小，随着海藻酸钠增加而增加，随着透明质酸的增加变化不太明显。扫描电镜结果提示材料随聚乙烯醇重均分子质量增加，材料中孔数减少。随醇解度增加，材料中孔数增多，分布均匀。随海藻酸钠增加，材料由片状结构变为蓬松的层状结构，孔洞逐渐增多。随透明质酸增加，材料孔洞数量增加，且孔径大小更均一，孔分布更均匀，材料由蓬松多孔结构转变为网状交织多孔结构。 结论：聚乙烯醇Mw14500，醇解度98％形成的孔形态结构最好，含水率高，随海藻酸钠和透明质酸的加入，材料具有丰富的网状孔洞结构。     

Self-healing composite hydrogel with antibacterial and reversible restorability conductive properties

Self-healable PAA/PPy–Fe composite hydrogels have been simply synthesized in one step and utilized for antibacterial and electrical conductivity application. The network of hydrogel is composed of polyacrylic acid (PAA) and Fe³⁺ ions with interlacing of the second polymeric chain of polypyrrole (PPy). In this study, ammonium persulfate (APS) was utilized to initiate the polymerization of both acrylic acid and pyrrole. Such hydrogels exhibited good mechanical properties and remarkable self-healing efficiency as well. The self-healing ability of the hydrogels was facilitated by ionic interaction between carboxylic anion groups (COO–) from polyacrylic acid (PAA) and Fe³⁺ ions. Moreover, the antibacterial activity of the composite hydrogels was examined on Escherichia coli via the disk diffusion method and the zone of inhibition was obtained in the range of 1.26–1.56 cm after incubation for 12 h. In addition, demonstration of the PAA/PPy–Fe composite hydrogels in electrical conductivity applications was performed in which the composite hydrogel was set up in an electrical circuit consisting of an LED and powered by 3 V batteries. The results showed that the electricity could light-up the LED through the PAA/PPy–Fe composite hydrogels and possessed reversible restorability, as indicated by the healed hydrogel consistently lighting-up the LED in the electrical circuit.

Self-healable PAA/PPy–Fe composite hydrogels have been simply synthesized in one step and utilized for antibacterial and electrical conductivity application.     

复合成骨细胞藻酸盐凝胶的体内成骨效应

目的:为使骨缺损的治疗简便可行,又要保证可靠的骨修复效果,实验将成骨细胞复合于藻酸钙水凝胶中,直接经皮注射动物体内了解其成骨情况.方法:实验于2006-01/2007-07在十堰市太和医院生命科学研究所实验室完成.将培养的兔骨髓基质成骨细胞复合于1.5%藻酸钠溶液,再加入葡萄糖酸钙,制备成骨细胞密度为1×1010 L-1、钙离子浓度为50 mmol/L的藻酸钙水凝胶.将20只健康成年新西兰大白兔左侧背部经皮注射成骨细胞-藻酸钙水凝胶复合物(实验侧),右侧注射单纯藻酸钙水凝胶(对照侧).于术后4,8,12周分别行X射线检查及组织学观察成骨情况.结果:20只健康成年新西兰大白兔均进入结果分析.X射线和组织学观察表明,实验侧成骨活跃,骨再生迅速,12周内,新生骨组织明显增多,且新生骨组织趋向成熟,X线片显示高密度影;而对照侧未见骨组织出现.结论:复合成骨细胞的藻酸钙凝胶经皮注射植入在动物体内异位成骨可靠、确切.     

On-off transport through a thermoresponsive hydrogel composite membrane.

A novel thermoresponsive composite membrane is described through which the permeation of molecules is dependent on the temperature of the milieu. The thermoresponsive composite membranes utilise a thermosensitive crosslinked polymeric hydrogel, which possesses a volume phase transition temperature (VPTT). The hydrogel was polymerised in situ within the pores of a sintered glass filter, through which significant permeation of molecules only occurred at temperatures above the VPTT of the hydrogel. It was found that the permeation of molecules through the thermoresponsive composite membranes could be modulated by changing the environmental temperature.     

复合成骨细胞藻酸盐凝胶的体内成骨效应

目的：为使骨缺损的治疗简便可行，又要保证可靠的骨修复效果，实验将成骨细胞复合于藻酸钙水凝胶中，直接经皮注射动物体内了解其成骨情况。方法：实验于2006—01／2007—07在十堰市太和医院生命科学研究所实验室完成。将培养的兔骨髓基质成骨细胞复合于1．5％藻酸钠溶液，再加入葡萄糖酸钙，制备成骨细胞密度为1×10^10L^-1、钙离子浓度为50mmol／L的藻酸钙水凝胶。将20只健康成年新西兰大白兔左侧背部经皮注射成骨细胞-藻酸钙水凝胶复合物（实验侧），右侧注射单纯藻酸钙水凝胶（对照侧）。于术后4，8，12周分别行X射线检查及组织学观察成骨情况。结果：20只健康成年新西兰大白兔均进入结果分析。X射线和组织学观察表明，实验侧成骨活跃．骨再生迅速．12周内，新生骨组织明显增多，且新生骨组织趋向成熟，X线片显示高密度影；而对照侧未见骨组织出现。结论：复合成骨细胞的藻酸钙凝胶经皮注射植入在动物体内异位成骨可靠、确切。     

Efficient artificial light-harvesting system constructed from supramolecular polymers with AIE property

Supramolecular luminescent materials in water have attracted much interest due to their excellent tunability, multi-color emission, and environment-friendly behavior. However, hydrophobic chromophores are often affected by poor solubility and aggregation-caused quenching effects in aqueous media. Herein, we report a water-phase artificial light-harvesting system based on an AIE-type supramolecular polymer. Specifically, dispersed nanoparticles in water were prepared from an AIE chromophore-bridged ditopic ureidopyrimidinone (M) based supramolecular polymer with the assistance of surfactants. By co-assembling the hydrophobic chromophores NDI as energy acceptor into the nanocarriers, artificial light-harvesting systems (M–NDI) could be successfully constructed, exhibiting efficient energy transfer and high antenna effects. Furthermore, the spectral emission of the system could be continuously tuned with a relatively small number of acceptors. This work develops an efficient supramolecular light-harvesting system in water, which has potential applications in dynamic luminescent materials.

An artificial light-harvesting system based on supramolecular polymers has been successfully constructed in aqueous media, which displays tunable emission with efficient energy transfer and high antenna effect.     

Thermosensitive chitosan-based hydrogel containing liposomes for the delivery of hydrophilic molecules.

A novel injectable in situ gelling thermosensitive chitosan-beta-glycerophosphate (C-GP) formulation has been recently proposed for tissue repair and drug delivery. The system can sustain the release of macromolecules over a period of several hours to a few days. However, with low-molecular-weight hydrophilic compounds, the release is generally completed within 24 h. In this study, liposomes were added to the C-GP solution and their effect on the viscoelastic properties of the system and release kinetics of encapsulated carboxyfluorescein was investigated. The gelation rate and gel strength were slightly increased by the presence of the liposomes. The in vitro release profiles demonstrated controlled delivery over at least 2 weeks. The release rate strongly depended on the liposome size and composition (i.e. addition of cholesterol), and on the presence of phospholipase in the release medium. The kinetics was not substantially modified when using liposomes prepared with a negatively-charged lipid or a lipid having a high phase transition temperature. These results indicate that the liposome-C-GP system rapidly gels at body temperature, and can sustain the delivery of low-molecular-weight hydrophilic compounds. A mathematical model was proposed to characterize the release kinetics.     

聚乙烯醇水凝胶弹性体复合物修复关节软骨缺损的实验研究

目的：研究应用聚乙烯醇水凝胶弹性体复合物作为关节软骨替代物修复成年犬的关节软骨缺损。方法：取8只成年犬随机均分为A、B两组，每组4只。在犬双后肢膝关节股骨内髁负重面制造软骨缺损区，在缺损区植入同等大小的聚乙烯醇水凝胶弹性体复合物。手术后8周和24周分别将A、B两组实验动物处死取材。在肉眼和光镜下观察植入物周围的软骨和软骨下骨，对应的半月板和胫骨面的软骨组织。结果：大体观察，实验动物术后关节功能良好，植入物在8周和24周均未见松动和脱落，与软骨下骨牢固结合。植入物周围软骨和对应部位的半月板和胫骨面软骨未见退变表现。光镜下观察8周和24周植入物周围未见软骨组织退变表现；软骨下骨组织长入钛纤维网孔隙中，形成生物力学固定；植入物周围无淋巴细胞浸润。结论：聚乙烯醇水凝胶弹性体具有与关节软骨类似的物理特性和良好的生物相容性，能作为关节软骨替代物修复关节软骨的缺损，恢复关节面的完整，维持关节功能。     

Visualizing and manipulating individual protein molecules

Single-molecule imaging and manipulation techniques have evolved in the past decade from mere jaw-dropping attractions to essential laboratory tools. By applying single-molecule methods important insights otherwise unavailable have been obtained on various biomolecular systems. Constantly improving single-molecule imaging techniques keep expanding the scale of the explorable spatial detail, thereby providing possible solutions to getting around the debilitating diffraction limit present in physiological-condition structural investigations. In some areas, such as motor protein studies, single-molecule methods have become part of the routine and essential research toolkit. Entire research fields, such as single-molecule force spectroscopy, have been born. In the present review single-molecule visualization and manipulation methods are reviewed with a focus on proteins. Relevant signals and prominent applications are discussed along with experimental examples and recent important results. Finally, the perspectives of the single-molecule field are explored.