聚氨酯胶黏剂的医用研究进展

聚氨酯胶黏剂因其优异的粘合性能,在医学领域越来越受到关注。寻求具有良好生物相容性、良好粘合性、可降解、无不良反应、消毒灭菌、在存在水的环境下能继续保持粘合特性的聚氨酯胶黏剂已成为医学领域的重点。该文综述了医用聚氨酯胶黏剂在创伤敷料、骨粘合剂、压疮的预防与治疗、经皮给药系统、手术薄膜及医药包装等方面应用的研究进展,并对聚氨酯胶黏剂应用于医学中的发展前景作了评述。     

骨髓间质干细胞与纤维蛋白胶生物相容性的实验研究

目的 采用体外细胞培养法对纤维蛋白胶的生物相容性进行研究，探讨它作为骨组织工程的载体材料的可行性。方法 取2月龄新西兰兔，麻醉后无菌条件下自股骨大转子处抽取骨髓4～6ml，淋巴细胞分离液离心后取单核细胞层，D-Hanks液洗涤离心2遍，悬浮于含10％FBS的DMEM培养液中，行原代培养。传代的细胞分为2组，一组继续用完全培养基培养，一组用条件培养基培养。分别收集细胞接种于含纤维蛋白胶的培养板中。不含材料的培养板中接种细胞作为对照。于不同时间进行处理，用于相差显微镜与扫描电镜观察，行MTT及碱性磷酸酶的含量测定。结果 骨髓间质干细胞可以在纤维蛋白胶表面生长，逐渐粘附。对照组与实验组在细胞光吸收值(OD值)、碱性磷酸酶的含量方面相近，统计学分析无显著差异。结论 纤维蛋白胶对兔骨髓间质干细胞的形态学，细胞生长增殖、分化都无影响。具有良好的生物相容性，可作为骨髓间质干细胞的生物载体。     

骨髓间质干细胞与纤维蛋白胶生物相容性的实验研究

目的采用体外细胞培养法对纤维蛋白胶的生物相容性进行研究,探讨它作为骨组织工程的载体材料的可行性.方法取2月龄新西兰兔,麻醉后无菌条件下自股骨大转子处抽取骨髓4~6ml, 淋巴细胞分离液离心后取单核细胞层,D-Hanks液洗涤离心2遍,悬浮于含10%FBS的DMEM培养液中,行原代培养.传代的细胞分为2组,一组继续用完全培养基培养,一组用条件培养基培养.分别收集细胞接种于含纤维蛋白胶的培养板中.不含材料的培养板中接种细胞作为对照.于不同时间进行处理,用于相差显微镜与扫描电镜观察,行MTT及碱性磷酸酶的含量测定.结果骨髓间质干细胞可以在纤维蛋白胶表面生长,逐渐粘附.对照组与实验组在细胞光吸收值(OD值)、碱性磷酸酶的含量方面相近,统计学分析无显著差异.结论纤维蛋白胶对兔骨髓间质干细胞的形态学,细胞生长增殖、分化都无影响.具有良好的生物相容性,可作为骨髓间质干细胞的生物载体.     

可吸收止血材料的生物相容性研究进展

可吸收止血材料是指用于伤口止血的可在体内降解吸收的生物医用材料,目前其在手术中止血发挥着重要作用。国内外近年来主要使用的可吸收止血材料包括壳聚糖、纤维蛋白原、α-氰基丙烯酸酯、氧化纤维素和胶原蛋白等,除止血效果外,其生物相容性正成为评价止血材料优劣的重要指标。在生物相容性的安全性和功能性原则指导下,对比它们在实验中的生物相容性结果,综合评价各类可吸收止血材料的生物相容性,为进一步研发良好生物相容性的可吸收止血材料以及日后的使用提供参考意见。     

新型生物止血材料--医用生物蛋白胶临床应用的效果观察

通过对术中应用医用生物蛋白胶止血的效果进行比较观察 ,说明医用生物蛋白胶具有良好的止血作用。按照不同专科及病种对应用组与对照组进行止血效果的对比观察。对比后发现应用组的止血效果优于对照组 ,并有促进组织愈合的作用。医用生物蛋白胶是一种新型的、有效的生物止血新材料     

新型生物止血材料——医用生物蛋白胶临床应用的效果观察

通过对术中应用医用生物蛋白胶止血的效果进行比较观察，说明医用生物蛋白胶具有良好的止血作用。按照不同专科及病种对应用组与对照组进行止血效果的对比观察。对比后发现应用组的止血效果优于对照组，并有促进组织愈合的作用。医用生物蛋白胶是一种新型的、有效的生物止血新材料。     

壳聚糖的生物相容性*

背景：壳聚糖是惟一一种被广泛应用于生物医学工程领域的碱性、带有正电荷的天然多糖,其生物相容性是决定这些应用价值的关键。 目的：综述了壳聚糖的生物相容性,包括组织相容性、血液相容性和力学相容性。 方法：由第一作者检索1990/2011 PubMed数据库、中国知网数据库及万方数据库有关壳聚糖及其衍生物在生物医学上的应用和生物相容性等方面的文献。 结果与结论：壳聚糖作为可生物降解高分子材料具有良好的组织相容性及与人体组织相匹配所需要的力学相容性,被逐渐应用于人工皮肤、手术缝合线、眼科修复、人工骨骼、牙齿修复、肿瘤治疗等方面。但壳聚糖的促凝血作用使其血液相容性很差,目前很多研究关注于寻找解决这一问题的方法,改善其血液相容性,扩展其在生物医学工程上的应用领域,使其更加安全有效地与人体心血管系统直接接触。 关键词：壳聚糖;组织相容性;血液相容性;力学相容性;生物材料 doi:10.3969/j.issn.1673-8225.2012.12.034     

止血防粘连生物纸的生物相容性研究

止血防粘连生物纸是一种采用天然多糖交链制成的新型可降解止血防粘连材料，具有纤维蛋白原活性增强作用和吸水后呈水凝胶结构起到隔离防粘连作用。本研究采用GB／T16886医疗器械生物学评价标准规定的全身急性毒性试验、皮内刺激试验、致敏试验、细胞毒性试验、植入试验和基因毒性试验方法评价生物纸的生物相容性，以验证其安全性和有效性。试验结果显示生物纸无全身急性毒性、无皮内刺激作用、无致敏作用，细胞毒性0～1级；植入肌肉内2周、4周和8周有轻度炎症反应，可见异物巨细胞，细胞内可见材料吞噬体；基因毒性采用鼠伤寒沙门氏菌回复突变试验（Ames试验），哺乳动物培养细胞染色体畸变试验和小鼠骨髓嗜多染红细胞微核试验均为阴性，说明生物纸无基因毒性。结论：生物纸具有良好的生物相容性，没有观察到不良反应，符合临床使用要求。     

生物可降解医用材料的应用和生物相容性

生物可降解医用材料的应用和生物相容性四川省生物医学材料监测中心王定国，吴增树可降解性材料的发展许多聚合生物材料进入机体后，可释放不同分子量和物理化学性质的分子。但这种释放不是真正的降解，而更多是聚合物添加剂的滤出或单体的解聚。早在６０年代，Ｒｏｂｅｒ...     

负压吸附式止血敷贴的制备及其生物相容性

背景：部分止血材料存在有毒性及价格昂贵的缺陷。 目的：观察负压吸附式止血敷贴在动物体内的生物相容性。 方法：健康家猪6只在肝及肾划出长约1 cm,深约0.5 cm的条形切口,用负压吸附式止血敷贴覆盖。移植前观察检测血常规、肝肾功能及体液免疫学指标;移植后第14天观察再次检测血常规、肝肾功能及体液免疫学指标,并观察局部组织形态学变化。 结果与结论：植入前后血生化和免疫学等指标差异无显著性意义(P > 0.05),肝肾组织切片显示无明显炎症反应,未见明显纤维细胞包膜。动物体内实验提示,负压吸附式止血敷贴无毒性、无排斥反应、无免疫反应、无过敏反应,具有良好的生物相容性。     

体外循环与血液生物相容性

行心外科手术的患者可因体外循环 ( CPB)中的血液激活而引发一系列术后严重并发症。认识并改善 CPB中的血液生物相容性可有效控制并消除 CPB后的不良反应     

Implant biocompatibility

The current ‘understanding’ of implant/tissue interactions is described in terms of implant form and implant chemistry for both ‘connective tissue’ and ‘blood contacting’ implants, and the importance of plasma protein adsorption in providing a possible rationalization of this understanding is explained. It is also suggested that the current view may be more relevant to hydrophobic materials than to implants in general, and may have to be modified as more hydrophilic materials are gradually introduced.     

The Influence of the Shape of Phagocytes on their Adhesiveness

Glucose is known to depress the adhesiveness to glass as well as the phagocytic activity of neutrophils and macrophages. Contact angle measurements indicate that this is not due to any decrease in cell surface free energy. The decreased adhesiveness to glass and depressed phagocytic activity under the influence of glucose are instead found to be due to the fact that glucose causes the phagocytes to retract their pseudopods and to become spherical in shape. It can be shown that a spherical shape tends to enhance the electrostatic repulsion between cells and between cells and other surfaces, while pseudopods help to overcome that electrostatic repulsion.

It is also shown that heparin does not interfere with the normal bizarre shape of neutrophils, while other anticoagulants such as ADP, CPD, and EDTA(for explanation of the symbols, see below) cause the neutrophils to become spherical. This explains why only when heparin is used as an anticoagulant, neutrophils will adhere to glass or nylon surfaces, and thus can be removed from whole blood by filtration through these media.

Finally, it could be demonstrated that platelet adhesiveness is also caused by the induction of a spiculated cell shape, rather than by a change in cell surface free energy.

It was previously noted by one of us (1) that human neutrophils, under in vitro conditions of high (4 and 8mg/ml) glucose levels, manifested a significant depression of their phagocytic activity as well as a decreased adhesiveness to glass surfaces. A similar effect of glucose on guinea pig macrophages has also been observed (2). We have since established that the depressed phagocytic activity and the decreased adhesiveness to glass at high glucose levels are not due to changes in the surface free energy of the phagocytes (see belaw). In view of the important role played by pseudopodic protrusions of the electro-negatively charged cells in their adhesion to other negatively charged surfaces (3), we proceeded to investigate the influence of glucose and a number of other additives on the shape of phagocytic cells.     

Adhesiveness and invasiveness of staphylococcal species in a cell culture model

A model was established for the study of adhesiveness and invasiveness of staphylococcal species. Five collection strains from each of the species Staphylococcus aureus, S. epidermidis, and S. saprophyticus and 26 fresh isolates from patients with urinary tract infections were tested for adhesiveness and invasiveness in HEp-2 cell cultures. All the strains of S. saprophyticus were able to invade the cells and localize intracellularly in the cultures, whereas the invasive potential among the strains of S. aureus and S. epidermidis was lower. The number of adhesive bacteria was also highest among the S. saprophyticus strains, whereas S. epidermidis was the least adhesive. The model may be suitable for further study of urinary tract infection strains.     

The Influence of the Shape of Phagocytes on their Adhesiveness

Glucose is known to depress the adhesiveness to glass as well as the phagocytic activity of neutrophils and macrophages. Contact angle measurements indicate that this is not due to any decrease in cell surface free energy. The decreased adhesiveness to glass and depressed phagocytic activity under the influence of glucose are instead found to be due to the fact that glucose causes the phagocytes to retract their pseudopods and to become spherical in shape. It can be shown that a spherical shape tends to enhance the electrostatic repulsion between cells and between cells and other surfaces, while pseudopods help to overcome that electrostatic repulsion.

It is also shown that heparin does not interfere with the normal bizarre shape of neutrophils, while other anticoagulants such as ADP, CPD, and EDTA(for explanation of the symbols, see below) cause the neutrophils to become spherical. This explains why only when heparin is used as an anticoagulant, neutrophils will adhere to glass or nylon surfaces, and thus can be removed from whole blood by filtration through these media.

Finally, it could be demonstrated that platelet adhesiveness is also caused by the induction of a spiculated cell shape, rather than by a change in cell surface free energy.

It was previously noted by one of us (1) that human neutrophils, under in vitro conditions of high (4 and 8mg/ml) glucose levels, manifested a significant depression of their phagocytic activity as well as a decreased adhesiveness to glass surfaces. A similar effect of glucose on guinea pig macrophages has also been observed (2). We have since established that the depressed phagocytic activity and the decreased adhesiveness to glass at high glucose levels are not due to changes in the surface free energy of the phagocytes (see belaw). In view of the important role played by pseudopodic protrusions of the electro-negatively charged cells in their adhesion to other negatively charged surfaces (3), we proceeded to investigate the influence of glucose and a number of other additives on the shape of phagocytic cells.     

Biomaterial biocompatibility and the macrophage

The biocompatibility of biomaterials at implant sites is controlled by the tissue/material interaction. A major cell in the tissue reaction is the macrophage. A summary is presented on macrophage mediation of cellular and humoral regulatory pathways in inflammatory and immune responses.     

The biocompatibility evaluation of mPEG-PLGA-PLL copolymer and different LA/GA ratio effects for biocompatibility

Biomaterial poly(lactic-co-glycolic acid) (PLGA), a FDA-approved material for clinical application, showed broad prospects in the past, but gradually can no longer meet present clinical developments and requirements, which we synthesized monomethoxy(polyethylene glycol)-poly(d,l-lactic-co-glycolic acid)-poly(l-lysine) (mPEG-PLGA-PLL) (PEAL) and have had some relevant reports. But studies on biocompatibility and the impacts of LA and GA ratio (LA/GA?=?60/40, 70/30, and 80/20) in main material have not yet been reported. Hemolysis experiment indicates that the hemolysis rate of PEAL extraction medium is less than 5%. Whole blood clotting time (CT), plasma recalcification time, activated partial thromboplastin time, prothrombin time evaluations, and dynamic CT assay show that the anticoagulant time of PEAL copolymer for blood is longer than that under negative and positive control. Protein adsorption assay indicates that PEAL films adsorb less protein than PLGA films (p?p?>?0.05). Complement activation test shows that PEAL surface does not induce complement activation. CCK8 measurement shows that the relative growth rates of Huh7, L02, and L929 cells co-incubated with PEAL nanoparticles (NPs) are more than 90%. PEAL NPs co-incubated with 5% foetal bovine serum or 2% bovine serum albumin, through dynamic light scattering assay, remain stable. Different concentrations of PEAL NPs co-incubated with zebrafish embryos at 6–72?h post fertilization show that comparing with negative control, 10, 100, or 500?μM of NPs for embryos development has no significant effects (p?>?0.05), only 1000 or 2000?μM of NPs has some effects (p?in vivo.     

Adhesiveness of dental resin-based restorative materials investigated with atomic force microscopy

This study aimed to show that the polymerization contraction of dental methacrylate-based materials, when used as adhesives on hard substrate, produces voids at the material-substrate interface. This phenomenology is closely related with the nanoleakage and the sealing ability of these materials. One prime/bond system, three restorative composite resins, and one orthodontic bonding system were cured by using mirror-like glass slides as a compliance-free reference substrate. The adhesive surface was analyzed by atomic force microscopy, and the polymerization contraction of bulk material was tested by laser beam-scanning method. Nanoperiodic structure of three-dimensional (3D) images, section analysis, and roughness characteristics (R(a) and R(z)) indicated that polymerization contraction produced voids at the interface. When the adhesive surface was exposed to oral simulating fluids (water, ethanol, and lactic acid solutions), hydrolytic degradation involved some hundreds of nanometers in depth. In visible light-cured (VLC) materials, the interface porosity decreased when an irradiation pause ( approximately 2 min) was carried out during gelation.