肝素结合改良医用聚氯乙烯材料的细胞毒性评价

目的评价肝素结合改良聚氯乙烯材料的细胞毒性及临床应用安全性.方法对肝素结合改良聚氯乙烯、改良聚氯乙烯等材料进行体外细胞培养,通过四甲基偶氮唑盐比色(MTT)实验观察细胞的活性和相对增殖率.结果改良聚氯乙烯及肝素结合的改良聚氯乙烯在吸光度及细胞的相对增殖率方面,结果优于传统聚氯乙烯材料;MTT实验表明肝素结合方法未改变材料的相对增殖率.结论改良聚氯乙烯及肝素结合的改良聚氯乙烯较传统材料相比,具有更优的细胞相容性,毒性轻微,可安全应用于临床.     

四甲基偶氮唑盐法评价牙体修复性纳米羟基磷灰石复合材料的体外细胞毒性

背景：越来越多的新型材料被纳入口腔领域应用的视野,对生物材料进行生物相容性评价是进入临床试验前的重点研究内容。 目的：通过体外细胞毒性实验评价自制牙体修复性纳米羟基磷灰石复合材料的生物相容性。 方法：根据ISO标准,采用四甲基偶氮唑盐比色法行体外细胞毒性实验,阴性对照组为DMEM培养液,阳性对照组为含有0.1%苯酚的DMEM培养液,实验组为受试材料的浸提液。测试人牙龈成纤维细胞在牙体修复性纳米羟基磷灰石复合材料浸提液中培养1,3,5 d的吸光度值,观察细胞形态变化,计算细胞相对增殖率,判断细胞毒性的级别。 结果与结论：实验组体外细胞毒性实验吸光度值均与阴性对照组差异无显著性意义(P > 0.05),与阳性对照组差异有显著性意义(P < 0.01),自制牙体修复性纳米羟基磷灰石复合材料体外细胞毒性级别为0~1级,初步认为其具有良好的生物相容性。     

牛磺酸对高温处理后神经上皮细胞存活和分化的影响

目的 探讨牛磺酸对高温处理后神经上皮细胞存活和分化的作用。 方法 取孕12.5d小鼠胚胎神经管上皮细胞进行原代培养，将其分为正常对照组、高温组和牛磺酸保护Ⅰ、Ⅱ组。显微镜下观察细胞的形态学变化，用四甲基偶氮唑盐(MTT)自动比色法测定细胞增殖活性，二脒基苯基吲哚(DAPI)染色法测定细胞凋亡率，免疫荧光法检测细胞中Caspase-3、微管相关蛋白-2(MAP-2)和胶质纤维酸性蛋白(GFAP)的表达。 结果 与正常对照组比较，高温组细胞增殖活性明显降低，细胞凋亡率明显升高，Caspase-3阳性细胞数明显增多，MAP-2阳性细胞数明显减少；与高温组比较，牛磺酸保护Ⅰ、Ⅱ组细胞活性显著升高，凋亡率显著降低，Caspase-3阳性细胞数明显减少，MAP-2表达明显增多；4个组比较，GFAP的表达差异无显著性。 结论 牛磺酸对高温处理后神经管上皮细胞的存活具有保护作用，并可能促进其向神经元方向分化。     

热休克蛋白40和热休克蛋白70抑制N2a细胞内突变亨廷顿蛋白聚积和毒性

目的 研究热休克蛋白40(HSP40)和热休克蛋白70(HSP70)对N2a细胞内突变亨廷顿蛋白(htt) 聚集物形成和毒性的影响. 方法 应用荧光显微镜术和免疫印迹技术检测单独或共同过表达HSP40和HSP70对N2a细胞内转染的突变htt(含有150个谷氨酰胺重复数,150Q)聚集物形成的影响;应用四甲基偶氮唑盐(MTT)法分析细胞活力和比色法检测细胞内活性氧(ROS)含量. 结果 单独过表达HSP40或HSP70,尤其是共同过表达HSP40和HSP70显著减少150Q htt在N2a细胞内的聚积,各组含有聚集物的细胞为(n=1 000):仅表达150Q htt 组约50%,过表达HSP40组约12%,过表达HSP70组约15%,共同过表达HSP40和HSP70组约5%.MTT分析结果显示,单独尤其是共同过表达HSP40和HSP70能显著增加150Q细胞的活力( P<0.01, n =3),同时减少ROS产生( P<0.01, n =3). 结论 HSP40和HSP70通过抑制细胞内突变htt聚积以及减少氧化应激而增加150Q N2a细胞活力.     

大黄素对人胃癌BGC-823细胞体外增殖和迁移的影响

目的 探讨大黄素对人胃癌BGC-823细胞增殖和迁移的影响。 方法 采用四甲基偶氮唑盐（MTT）比色法测定不同浓度大黄素对体外培养人胃癌BGC-823细胞增殖的影响;采用流式细胞术测定大黄素对人胃癌BGC-823细胞的细胞周期影响;采用划痕损伤实验测定大黄素对人胃癌BGC-823细胞迁移的影响。 结果 MTT法显示,大黄素能抑制人胃癌BGC-823细胞増殖,呈现浓度依赖性;流式细胞术显示,人胃癌BGC-823细胞的细胞周期主要停滞在G₀/G₁期;划痕损伤实验表明,人胃癌BGC-823细胞迁移受到明显的抑制。 结论 大黄素对人胃癌BGC-823细胞的增殖和迁移具有明显的抑制作用,且呈浓度依赖性,并可使人胃癌BGC-823细胞增殖周期停滞于G₀/G₁期。     

MC3T3-E1细胞与多组分纳米羟基磷灰石基三维复合支架材料的相容性

目的 观察MC3T3-E1细胞在复合支架材料上的黏附、增殖及形态,评价多组分纳米羟基磷灰石基三维复合支架材料的生物相容性.方法 采用仿生学方法,将壳聚糖、羟基磷灰石、明胶、果胶按照一定比例制作成多组分纳米羟基磷灰石基三维复合支架材料.在复合支架材料上接种MC3T3-E1细胞,通过倒置相差显微镜、HE染色、扫描电镜、四甲...     

血管生成靶向纳米粒子c(RGDyK)@SiO2@Fe3O4的合成及生物性能*

背景：SiO2含有较多的羟基官能团,可进一步功能化而与靶向性配体相偶联,从而拓展Fe3O4@SiO2纳米粒子在生物医药领域的应用。 目的：探讨靶向性纳米粒子c(RGDyK)@SiO2@Fe3O4)的合成方法,并对其性能进行测试。 方法：采用一壶化学共沉淀法合成油酸修饰的疏水性Fe3O4纳米粒子,采用反相微乳液法合成生物相容性Fe3O4@SiO2复合纳米粒子;以3-氨丙基三乙氧基硅烷为偶联剂将复合粒子中SiO2表面的羟基氨基化、醛基化,加入1.0 mg c(RGDyK)多肽,超声震荡下反应生成c(RGDyK)@SiO2@Fe3O4纳米粒子。将Fe3O4@SiO2或c(RGDyK)@SiO2@Fe3O4与人脐静脉细胞融合细胞(EA.hy926)共培养24,48,72 h进行检测。 结果与结论：实验合成的Fe3O4@SiO2复合纳米粒子的平均粒径为40 nm,应用3-氨丙基三乙氧基硅烷可将c(RGDyK)成功耦合于复合粒子的SiO2表面。Fe3O4@SiO2或c(RGDyK)@SiO2@Fe3O4与EA.hy926共培养24 h,EA.hy926细胞活性明显增高(P < 0.05),以c(RGDyK)@SiO2@Fe3O4的作用更明显;共培养72 h后,细胞活性在各组间差异无显著性意义    (P > 0.05)。电镜观察发现,EA.hy926细胞对靶向性c(RGDyK)@SiO2@Fe3O4粒子的吞噬能力明显强于非靶向性Fe3O4@SiO2粒子。说明实验合成的c(RGDyK)@SiO2@Fe3O4纳米粒子具有良好的生物相容性、超顺磁性及较高的血管内皮细胞靶向性,是一种优良的生物材料。       

色钉菇乙酸乙酯相对SH-SY5Y细胞的保护作用

目的探讨色钉菇乙酸乙酯提取物对1-甲基-4-苯基吡啶离子(MPP+)诱导损伤的多巴胺能神经元的保护作用。方法以SH-SY5Y细胞系为对象,首先测定MPP+孵育48 h时的半致死量(IC50)。然后用25mg/L、50mg/L、100mg/L等剂量的乙酸乙酯提取物预先孵育4 h,随后加入1.0mmol/L(IC50值)MPP+孵育48 h。通过MTT法检测细胞活性;Hoechst染色法、AnnexinⅤ-FITC/PI双染法流式细胞术检测法观察细胞凋亡情况。利用DCFHDA检测色钉菇乙酸乙酯提取物对细胞内活性氧(ROS)水平的影响。结果 1.0mmol/L MPP+孵育48 h时达到半致死剂量,MPP+的损伤浓度确定为1.0mmol/L。预先经色钉菇乙酸乙酯相(50mg/L)孵育,可显著提高SH-SY5Y细胞的活力,降低细胞凋亡率。MPP+损伤后ROS水平急剧升高,而25mg/L、50mg/L、100mg/L乙酸乙酯提取物干预后ROS水平下降。结论 50mg/L色钉菇乙酸乙酯相可显著减轻MPP+对SH-SY5Y细胞的毒性损伤,具有显著的保护作用。     

人脂肪源性干细胞的分离及生物学性状的鉴定

目的 建立从人脂肪抽吸物中分离培养脂肪来源干细胞(ASCs)的方法,并从形态学、生长动力学、表面标记物和分化能力等方面进行鉴定.方法从4例行腹部脂肪抽吸术的健康成年女性患者获得脂肪组织,通过酶消化法分离和培养脂肪干细胞,并传代培养至20代,观察细胞形态;四甲基偶氮唑盐(MTT)法测定和比较第3、9、15和20代细胞生长...     

纳米羟基磷灰石和氢氧化钙对成牙本质细胞活性影响的比较

背景：将纳米羟基磷灰石与成牙本质细胞共同培养能更直观反映羟基磷灰石作为齿科盖髓材料的细胞相容性,但体外培养成牙本质细胞较困难。 目的：观察纳米羟基磷灰石和氢氧化钙对小鼠成牙本质细胞的活性的影响。 方法：取胎鼠下颌第一磨牙牙胚,采用组织块培养法对小鼠牙乳头细胞进行原代培养,倒置显微镜下挑选具有成牙本质样细胞形态的细胞观察细胞形态及生长情况。采用RT-PCR法对细胞牙本质涎磷蛋白的表达进行鉴定,确定为成牙本质样细胞。取对数生长期的第4代成牙本质样细胞,分别用含有100 mg/L纳米羟磷灰石和100 mg/L氢氧化钙的培养基培养1,3,5,7天,并设置空白对照组。 结果与结论：CCK-8法检测结果显示,培养1,3,5,7 d,纳米羟基磷灰石组的细胞生长良好。培养3,5,7 d,氢氧化钙组细胞活性低于空白对照组(P < 0.01)。碱性磷酸酶测定法检测结果显示,羟基磷灰石和氢氧化钙均对碱性磷酸酶活性无明显影响。结果证实,纳米羟基磷灰石对成牙本质细胞活性无影响,氢氧化钙对其细胞活性有抑制作用。     

Gentamicin-releasing urethral catheter for short-term catheterization

Urethral catheters, widely used for the drainage of the bladder, are associated with most urinary tract infections (UTIs) that account for 40% of all episodes occurring in acute-care hospitals. This study aimed to develop a gentamicin-releasing catheter that effectively prevents UTIs for short-term catheterization. For physical loading of gentamicin, the urethral catheters were coated by the simple dipping method with poly(ethylene-co-vinyl acetate) (EVA) and EVA/poly(ethylene oxide) (PEO) blends containing gentamicin. By varying the molecular weight (MW) and contents of PEO in the blends, various catheter surfaces were produced. In vitro drug release studies demonstrated that all the coated catheters exhibited sustained release up to 7 days; however, the release pattern was significantly dependant on the coating layers. Of the coated catheters, EVA/PEO (MW = 100k)-coated catheters were utilized to evaluate the antibacterial activity using an inhibition zone test, since they showed a promising drug release behavior and had PEO-rich biocompatible surfaces. In accordance with drug release behavior, EVA/PEO-coated catheters exhibited antibacterial activities for 7 days against Proteus vulgaris, Staphylococcus aureus and Staphylococcus epidermidis. These results imply that the catheters coated with EVA/PEO have a potential for short-term catheterization.     

Norfloxacin-releasing urethral catheter for long-term catheterization

Norfloxacin-releasing urethral catheters were prepared for the purpose of preventing urinary tract infections during long-term catheterization. The outer and inner surfaces of the catheters were coated with poly(ethylene-co-vinyl acetate) (EVA) and an amphiphilic multiblock co-polymer (PEO2kPDMS), composed of poly(ethylene oxide) and poly(dimethyl siloxane). Norfloxacin, a fluoroquinolone synthetic antibiotic, was impregnated into a coating layer. The in vitro drug release behavior was monitored for 30 days, the surface topography was investigated using scanning electron microscopy (SEM) and the antibacterial activity against different bacteria implicated in urinary tract infection was evaluated by the in vitro inhibition zone test. All the coated catheters showed continuous delivery of norfloxacin for up to 30 days owing to hydrophobic natures of norfloxacin and EVA. PEO2kPDMS incorporated in a coating layer produced a smooth and uniform surface. The coated catheters created considerable inhibition zones for 10 days against Escherichia coli. Klebsiella pneumoniae and Proteus vulgaris, indicating the continuous release of norfloxacin. Overall, it was evident that the catheters coated with EVA/PEO2kPDMS blends containing norfloxacin have a promising potential for the clinical use in patients undergoing long-term catheterization.     

Norfloxacin-releasing urethral catheter for long-term catheterization

Norfloxacin-releasing urethral catheters were prepared for the purpose of preventing urinary tract infections during long-term catheterization. The outer and inner surfaces of the catheters were coated with poly(ethylene-co-vinyl acetate) (EVA) and an amphiphilic multiblock co-polymer (PEO_2kPDMS), composed of poly(ethylene oxide) and poly(dimethyl siloxane). Norfloxacin, a fluoroquinolone synthetic antibiotic, was impregnated into a coating layer. The in vitro drug release behavior was monitored for 30 days, the surface topography was investigated using scanning electron microscopy (SEM) and the antibacterial activity against different bacteria implicated in urinary tract infection was evaluated by the in vitro inhibition zone test. All the coated catheters showed continuous delivery of norfloxacin for up to 30 days owing to hydrophobic natures of norfloxacin and EVA. PEO_2kPDMS incorporated in a coating layer produced a smooth and uniform surface. The coated catheters created considerable inhibition zones for 10 days against Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris, indicating the continuous release of norfloxacin. Overall, it was evident that the catheters coated with EVA/PEO_2kPDMS blends containing norfloxacin have a promising potential for the clinical use in patients undergoing long-term catheterization.     

Gentamicin-releasing urethral catheter for short-term catheterization

Urethral catheters, widely used for the drainage of the bladder, are associated with most urinary tract infections (UTIs) that account for 40% of all episodes occurring in acute-care hospitals. This study aimed to develop a gentamicin-releasing catheter that effectively prevents UTIs for short-term catheterization. For physical loading of gentamicin, the urethral catheters were coated by the simple dipping method with poly(ethylene-co-vinyl acetate) (EVA) and EVA/poly(ethylene oxide) (PEO) blends containing gentamicin. By varying the molecular weight (MW) and contents of PEO in the blends, various catheter surfaces were produced. In vitro drug release studies demonstrated that all the coated catheters exhibited sustained release up to 7 days; however, the release pattern was significantly dependant on the coating layers. Of the coated catheters, EVA/PEO (MW = 100k)-coated catheters were utilized to evaluate the antibacterial activity using an inhibition zone test, since they showed a promising drug release behavior and had PEO-rich biocompatible surfaces. In accordance with drug release behavior, EVA/PEO-coated catheters exhibited antibacterial activities for 7 days against Proteus vulgaris, Staphylococcus aureus and Staphylococcus epidermidis. These results imply that the catheters coated with EVA/PEO have a potential for short-term catheterization.     

Cytotoxicity of alkyl-2-cyanoacrylate adhesives

The cytotoxicity of methyl- and isobutyl-2-cyanoacrylate adhesives was determined using a rat polymorphonuclear leukocyte suspension. Cell degranulation increased and migration decreased on addition of the alkyl-2-cyanoacrylates to the suspension in a concentration-dependent manner. When acetylsalicylic acid or indomethacin, inhibitors of prostaglandin H synthase, were present, the cytotoxicity observed on addition of the adhesives to the leukocytes decreased up to eightfold in a dose-dependent manner as detected by trypan blue exclusion. Likewise, glutathione peroxidase and superoxide dismutase lowered such cytotoxicity resulting from the cyanoacrylates up to eight- and sevenfold, respectively. The data suggested that the adhesives may have generated lipid hydroperoxides that activated prostaglandin and thromboxane biosynthesis, and participated in membranal oxidation and lysis. Such a mechanism may contribute to understanding the thrombotic events associated with the necrosis observed on application of these adhesives to tissues in vivo.     

留置尿管致尿道狭窄原因分析及护理防范

目的:探讨临床中工作中留置尿管对尿道的影响及防范措施。方法:回顾性分析24例病人由于留置尿管后造成尿道狭窄的原因,根据其发生原因了解相应的防范措施,以减少临床工作中留置尿管的并发症的发生。结果:24例尿道狭窄病人中尿道损伤14例,尿道感染8例,导尿管选择和使用不当2例。结论:留置尿管过程中如操作不当可能会导致尿道狭窄,其中尿道损伤发生率最高,是导致尿道狭窄的主要原因,其次为尿道感染,临床工作中应尽可能减少上述原因的发生,防止尿道狭窄的发生。     

Cytotoxicity evaluation of ceramic particles of different sizes and shapes

When artificial hip or knee joints are implanted in the human body, they release metallic, ceramic, and polymeric debris into the surrounding tissues. The toxicity of the released particles is of two types: chemical, caused by the released soluble ions and monomers, and mechanical, a result of mechanical stimulation produced by the insoluble particles. In this study, the cytotoxicity of particles of TiO2, Al2O3, ZrO2, Si3N4, and SiC for murine fibroblasts and macrophages were examined to evaluate just their mechanical toxicity because these particles are not expected to release soluble metal ions. Different sizes and shapes of TiO2 particles were used to evaluate the effect of size and shape on particle cytotoxicity. The results suggest that the cytotoxicity of ceramic particles does not depend on their chemical species. Cytotoxicity levels were lower than those of corresponding metal ions, indicating that the mechanical toxicity of particles is lower than the chemical toxicity of released soluble ions and monomers. The differences in size did not affect the mechanical toxicity of these particles. The dendritic particles had a higher cytotoxicity level for macrophages than did spindle and spheric particles.