肝素涂层医用聚氯乙烯的细胞毒性研究

本研究通过肝素—氯烃基二甲基代苯甲胺复合物(A组)、肝素—苯扎溴胺复合物(B组)和肝素—聚乙烯亚胺复合物对医用聚氯乙烯体外循环管道进行了肝素涂层,同时采用材料直接接触细胞培养法和四唑盐(MTT)比色试验评价各种涂层材料的细胞毒性。结果显示A、B组材料直接接触L-929细胞后24h即引起细胞大量死亡,而C组材料直接接触后具有良好的细胞相容性。MTT比色试验也表明A、B两种涂层材料具有较低的OD值。A、B两种涂层材料具有较强的细胞毒性,而C方法处理的聚氯乙烯材料不引起细胞死亡,具有进一步临床应用前景。     

肝素涂层体外循环管道抗凝血性能的研究

目的 评测3种离子键肝素涂层体外循环管道的抗凝血性能和稳定性。方法 用PT和APTT对不同浓度肝素—氯烃基二甲基代苯甲胺(HBC)复合物涂层体外循环管道的凝血性能进行评测，同时测试体外转流对3种肝素涂层管道抗凝血性能的影响。结果 3种肝素涂层方法均能够将肝素分子结合于材料表面并具有抗凝活性，其中HBC复合物和肝素—聚乙烯亚胺复合物处理的体外循环管道经体外转流96h后仍具有较佳的抗凝血活性。结论 离子键肝素涂层因结合物质不同其稳定性也不同；HBC复合物和肝素—聚乙烯亚胺复合物处理的体外循环管道肝素分子结合较牢固，能够满足临床短期使用需要。     

肝素涂层体外循环管道的制备及生物学性能评价

通过离子键方式将肝素分子结合于体外循环医用聚氯乙烯管道中 ,进行了体外转流抗凝血性能测定和细胞毒性、肌肉植入等生物学性能评价 ,结果显示肝素分子结合于聚氯乙烯材料表面 ,同时筛选出具有抗凝血活性和良好生物相容性的聚乙烯亚胺 肝素涂层方法。     

新型无镍ZrCuFeAlAg非晶态合金的体外细胞毒性

通过检测一种新型无镍Zr-基非晶态合金Zr60.14Cu22.31Fe4.85Al9.7Ag3的体外细胞毒性,并与常用生物医用合金Ti6Al4V的细胞毒性进行比较,以评价该材料的生物相容性。按照ISO 10993-5:1999及GB/T 16886.5-1997标准,将Zr60.14Cu22.31Fe4.85Al9.7Ag3、纯Zr及Ti6Al4V材料按试件表面积与培养液体积比为1cm2/mL和0.5cm2/mL分别提取浸提液,再用Cell Counting Kit-8(CCK-8)试剂分别检测以浸提液培养的人骨肉瘤MG-63细胞1、3、5d后的光密度(OD)值并计算细胞相对增殖率(RGR)以评价其细胞毒性。将人骨肉瘤MG-63细胞培养于合金样本表面3d后固定并分别采用激光共聚焦显微镜(LSCM)及扫描电镜(SEM)观察各组材料表面细胞生长形态。间接细胞毒性试验CCK-8结果提示,Zr60.14Cu22.31Fe4.85Al9.7Ag3组及纯Zr组与Ti6Al4V组相同,其1、3、5d的细胞相对增殖率均大于85%,经细胞毒性分级均为0或1级,符合国家医用材料合格标准;直接细胞毒性试验LSCM观察人骨肉瘤MG-63细胞在各组材料样本表面生长形态相似,并且各组与阴性对照组细胞数量之间无明显差别;SEM观察到人骨肉瘤MG-63细胞于各组材料表面贴壁生长及细胞形态均良好,基本符合医用材料标准,表明该材料具有良好的细胞生物相容性。因此,我们初步认为它可成为潜在的生物医用替代材料,尤其用于骨科植入材料。     

氟涂层镁铝合金的体外生物相容性研究

目的研究氟涂层镁铝合金的体外生物相容性。方法实验分为空白对照组(N组)、镁铝合金组(M组)、氟涂层镁铝合金组(F组)和阳性对照组(P组)4组。细胞毒性实验:将L929细胞在各组的DMEM浸提液中培养,光学显微镜下观察细胞生长状况,应用WST-1法测量光密度(OD)值。溶血实验:按GB-T 16175-2008《医用有机硅材料生物学评价实验方法》第13部分《溶血试验》进行实验。测量各样本的OD值,计算溶血率。豚鼠最大剂量致敏实验,按照GB-T 16886.10-2005《医疗器械生物学评价》第10部分《刺激与迟发型超敏反应试验》进行实验。观察激发阶段去除贴附片后24、48、72h豚鼠皮肤致敏情况。结果各观察期F组的形态分级为0级,M组为4级。各组各观察期内OD值差异均有统计学意义(F=312.96,P=0.000)。第3天,实验组OD值均高于P组(1.050±0.065 vs 0.292±0.010)(P0.05)。第5天、第7天,F组与N组OD值(1.429±0.096 vs 1.622±0.156,0.928±0.040 vs 0.995±0.070)处于同一水平(P0.05),均高于P组(0.270±0.015,0.281±0.006)(P0.05)。M组溶血率为68.3%,F组为0.8%。24 h、48 h和72 h后N组、M组、F组皮肤均无红斑。结论氟涂层镁铝合金体外实验显示具有良好的生物相容性。     

海藻酸钠交联肝素涂层在体外循环及人工心肺支持装置管路中的应用

背景：目前国内体外循环心脏手术使用的非肝素涂层管路和插管对血液破坏大、炎性反应重,影响心脏手术后患者的恢复和生存。 目的：采用生物医用高分子材料研制新型体外循环管道肝素涂层技术,并对其稳定性及抗凝血性能进行研究。 方法：利用CaCl₂将活化医用聚氯乙烯体外循环管道内表面修饰形成Ca2+膜,并与海藻酸钠和肝素交联;其中Ca²⁺与海藻酸钠、肝素钠中的Na+反应,从而使线型聚合物分子发生交联,形成化学交联海藻酸钠-肝素复合物的网状结构,实现生物型材料肝素化涂层。 结果与结论：CaCl₂修饰活化医用聚氯乙烯体外循环管道并与海藻酸钠和肝素交联反应,形成生物型高分子材料肝素化涂层管道,试验证明肝素化涂层管道具有良好的血液相容性、稳定性、抗凝血性能,可满足体外循环中短期转流的要求。     

肝素涂层插管生物相容性评价

对肝素涂层插管和未涂层插管设计了抗凝血、血栓形成观察以及溶血、细胞毒性、炎性和免疫反应等多种试验，从多角度综合对肝素涂层插管材料进行生物相容性评价。通过活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、纤维蛋白原降解产物(FIB)、凝血酶时间(TT)、血小板活化因子、纤维蛋白吸附等试验，测定样品的体外抗凝血性，然后通过半体内血栓形成试验，模拟插管在动物体内的使用环境和过程，观察样品引起血栓形成的状况。同时，通过溶血试验和细胞毒性试验以及炎症反应、补体激活、免疫球蛋白等检测，进一步对样品进行血液相容性评价。结果显示，肝素涂层实验组APTT和TT得到有效延长，而其他体外抗凝指标未见显著变化；在动物半体内模型试验和检测中，肝素涂层实验组6 h血栓形成的各项指标均低于未涂层对照组，表明肝素涂层通过抑制内源性凝血途径达到了预期的抗凝效果；而溶血率、细胞毒性、炎症反应、补体激活、免疫球蛋白等方面的试验结果与未涂层对照组无差异，表明肝素涂层对材料的血液相容性无不良影响。结果表明，肝素涂层显著提高了动静脉插管的体内外抗凝血性，具有良好的生物相容性，可提高临床应用的安全性。     

人工髓核材料-聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性研究*

目的评估人工髓核材料聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性。方法根据ISO10993-1标准,采用细胞毒性试验(琼脂扩散法)、皮内刺激试验、Ame's致突变试验、微核试验和体内植入(360天)试验对聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性进行评估。结果聚乙烯醇水凝胶/聚乙烯纤维复合物的细胞毒性评分小于Ⅰ级,细胞生长无明显抑制现象,对皮内无刺激作用,Ames致突变试验为阴性,微核出现率为3.48‰,无致突变反应。体内植入符合植入材料生物学评价要求。结论聚乙烯醇水凝胶/聚乙烯纤维复合物具有良好的生物安全性,是一种无毒、对皮肤及肌肉、椎间隙无刺激作用的生物医用材料,在动物体内不引起排异反应,可应用于临床。     

HA涂层对3D打印钛合金材料安全性的影响

目的 探究羟基磷灰石（HA）涂层对3D打印钛合金材料生物安全性的影响。方法 将3D打印钛合金材料分为有HA涂层材料和无HA涂层材料两个样品组。分别进行细胞毒性、刺激、急性毒性、溶血、回复突变、小鼠淋巴瘤试验和细胞致癌试验,将两种材料的生物安全性评价进行对比,观察羟基磷灰石（HA）涂层对3D打印钛合金髋臼杯材料的生物安全性的影响。结果 在细胞毒性试验中,有HA涂层组的细胞存活率为（117±6）%,无HA涂层组的细胞存活率为（106±14）%,均大于75%;在刺激试验中,两种材料生理盐水浸提液组的积分均为0,玉米油浸提液组的积分均为0.06;在急性毒性试验中,各组小鼠体重均稳步增长;在溶血试验中,有HA涂层材料的溶血率为0.125%,无HA涂层材料的溶血率为-0.257%;在Ames试验中,两种材料的回复突变菌落数均在正常值范围内;在小鼠淋巴瘤试验中,各剂量组的突变频率MF均大于或小于阴性对照组,且稍微高于阴性对照组的剂量组均不超过126×10-6。结论 两种材料均不具有细胞毒性、急性毒性、刺激和遗传毒性,同时也证明了两种材料都不具有溶血作用。有HA涂层材料和无HA涂层材料均表现出良好的生物安全性,证明HA涂层材料是安全可靠的,这也为未来开钛合金材料通过添加涂层改性提供了安全依据。     

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.     

体外循环聚氯乙烯管路地塞米松涂层的性能

背景：将地塞米松以某种涂层方式固定到体外循环管道表面,既可持续地起到抗炎作用,又不至于由于血药浓度过大而产生不良反应,最大限度地发挥地塞米松的抗炎作用。 目的：研制新型抗凝血活性的地塞米松磷酸钠涂层管路,评价涂层管道稳定性、抗凝活性及抗血小板等性能。 方法：用浓硫酸、聚乙烯亚胺依次预处理聚氯乙烯体外循环管路表面。分别通过预混、离子键两种方式制备地塞米松磷酸钠涂层聚氯乙烯体外循环管道,对涂层管道进行涂层物定量分析,以未涂层的聚氯乙烯体外循环管路为空白对照,评价3组抗凝血、抗血小板、抗蛋白黏附等性能及涂层聚氯乙烯体外循环管道的体外释放特性。 结果与结论：预混及离子键制备的地塞米松磷酸钠涂层聚氯乙烯管道表面固定地塞米松磷酸钠的最大固定量分别为(2.06±0.68),(3.33±0.75) μg/cm²。预混制备的地塞米松磷酸钠涂层聚氯乙烯管道抗凝血、抗血小板及蛋白黏附效果优于离子键制备的地塞米松磷酸钠涂层聚氯乙烯管道和空白对照组(P < 0.05),且体外释放效果优于离子键制备的地塞米松磷酸钠涂层聚氯乙烯管道。表明通过预混方式制备的地塞米松磷酸钠涂层缓释及抗凝性能良好,有抗血小板黏附及血栓形成的功能,能满足体外循环中短期转流的要求。     

溴代呋喃酮对聚氯乙烯材料表面表皮葡萄球菌生物膜形成的影响

BACKGROUND: Quorum sensing system plays a very important role in the formation of bacterial biofilm. Most of brominated furanones blocked the quorum sensing of bacteria after combining with the receptors of autoinductors in sensing system, however, some brominated furanones play a role of bacterial autoinductors and promote the formation of bacterial biofilm. OBJECTIVE: To investigate the influence of different types of brominated furanones on the biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride materials. METHODS: Polyvinyl chloride materials were divided into control group and furanone 1-3 groups. The polyvinyl chloride materials in the control group were soaked with ethanol for 5 minutes. Three kinds of brominated furanones with representative chemical structure were taken as furanone 1-3 groups which were respectively 3,4-dibromo-5-hydroxyl-furanone,4-bromo-5-(4-methoxypheny)-3-(methylamino)- furanone and 3,4-dibromo-5,5-dimethoxypheny-2(5H)-furanone. The surface coating of the polyvinyl chloride materials in these four groups all underwent modification and then were co-cultivated with Staphylococcus epidermidis together. RESULTS AND CONCLUSION: Compared with the control group, Staphylococcus epidermidis bacterium community quantity on the surface of polyvinyl chloride material was smaller, and the thickness of bacterium biofilm in furanone-2 group was thinner. There was no obvious bacterial biofilm structure formation on the surface of polyvinyl chloride material at the 18th hour of culture. The Staphylococcus epidermidis bacterium community quantity and the thickness of bacterium biofilm in furanone 1 and furanone 3 groups were closer to the control group. These results show that the impact of different types of brominated furanones on biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride materials is different, among them, 4-bromo-5-(4-methoxypheny)-3-(methylamino)-furanone can inhibit the growth of Staphylococcus epidermidis and the bacterial biofilm formation on the surface of polyvinyl chloride materials.      

Colonization of bacteria on polyvinyl chloride and Teflon intravascular catheters in hospitalized patients.

During an 8-month period all intravascular catheters were removed by sterile technique upon completion of use and submitted to the hospital microbiology laboratory. All catheters were routinely cultured by the semiquantitative culture technique, with greater than or equal to 15 colonies being defined as a positive result. Of the 687 Teflon catheters cultured, 6.9% were positive by culture, compared with 24.6% of 77 polyvinyl chloride catheters (P less than 0.001). Also, colonization of coagulase-negative staphylococci on polyvinyl chloride was more than on Teflon. These data suggest that polyvinyl chloride catheters are colonized more frequently with organisms than are Teflon catheters; additionally, there is an increased affinity of coagulase-negative staphylococci for polyvinyl chloride as compared with Teflon, substantiating our previous observations with an in vitro system. We conclude that the type of catheter material may be important in determining the incidence of catheter-related infections and in selective colonization by coagulase-negative staphylococci.     

Endothelial cell response to polyvinyl chloride-packaged GORETEX: effect of surface contamination

A Fourier transform infrared spectroscopic study of polyvinyl chloride packaged GORETEX vascular prostheses indicated that their internal and external surfaces were coated with an additive layer presumed to be derived from the polyvinyl chloride packaging. This layer was not removed by washing in phosphate buffered saline but was soluble in trimethyl pentane and hexane. Some other treatments of GORETEX and the packaging were shown to remove the contaminant from the surface and this correlated with an inferior in vitro aortic endothelial cell response. Analyses of materials extracted from both the polyvinyl chloride and the GORETEX surface indicated that the major surface component was a long chain aliphatic ester, either a plasticizer or a lubricant constituent.     

Heparinized styrene-butadiene-styrene elastomers.

A heparinized high-strength elastomer has been developed which is potentially useful as a nonthrombogenic vascular prosthesis. A surface hydroxylated styrene-butadiene-styrene (SBS) block copolymer with at least 40% extent of reaction after glow-discharge cleaning was coated with a 20% acetylated polyvinyl alcohol/heparin mixture containing glutaraldehyde and magnesium chloride. After curing at 80 degrees C for 100 min, the polyvinyl alcohol, heparin, and hydroxylated SBS were covalently bound to each other by acetal bridges. The effects of the various substrate and coating parameters were optimized to achieve very strong adhesion between the coating layer and the surface hydroxylated SBS. Heparin was not leached from the surface of the new material using 3M saline at pH 7.4 despite a detection limit of 10(-5) micrograms heparin/cm2 min. Prolonged partial thromboplastin times of greater than 1200 sec were observed (control: PTT = 120 sec). Preliminary ex vivo testing using a simple arteriovenous shunt in the leg of a rabbit showed good thromboresistance. The heparinized SBS shunt chamber remained patent for more than two hours without desorption of heparin. It was concluded that surface hydroxylated SBS heparinized by acetal coupling owed its thromboresistance to the heparin covalently bound to the surface and not to a microenvironment of heparin in solution at the blood/material interface.     

Efficient Inhibition of Ovarian Cancer by Gelonin Toxin Gene Delivered by Biodegradable Cationic Heparin-polyethyleneimine Nanogels

The use of toxins for cancer therapy has great promise. Gelonin, a potent plant toxin, causes cell death by inactivating the 60S ribosomal subunit. Recently, we developed a novel gene delivery system using biodegradable cationic heparin-polyethyleneimine (HPEI) nanogels. In the current study, the antitumor activity of a recombinant plasmid expressing gelonin (pGelonin) on human ovarian cancer was assessed. The application of HPEI nanogels, was also evaluated. Gelonin-cDNA was cloned into the pVAX1 plasmid vector and transfected into SKOV3 human ovarian cancer cells using biodegradable cationic HPEI nanogels. The expression of gelonin in vitro and in vivo was confirmed using RT-PCR and western blot analysis. Cell viability and apoptosis were examined using an MTT assay and flow cytometric analysis. For the in vivo study, an SKOV3 intraperitoneal ovarian carcinomatosis model was established, and nude mice were randomly assigned into four groups receiving i.p. administration of pGelonin/HPEI complexes, pVAX/HPEI complexes, HPEI alone and 5% glucose solution. The tumor weight was monitored, and a TUNEL assay and Ki-67 immunohistochemistry were performed to evaluate apoptosis and cell proliferation in the tumor tissue sections, respectively. Gelonin was efficiently expressed in SKOV3 cancer cells in vitro and in vivo using pGelonin incorporated with HPEI nanogels. The pGelonin/HPEI complexes inhibited cell viability and induced apoptosis in the cell culture. Treatment for intraperitoneal carcinomatosis with pGelonin/HPEI complexes reduced the tumor weight by ~58.55% compared to the control groups (P<0.05). The antitumor effect was accompanied by increased apoptosis and reduced cell proliferation (P<0.05). No significant side effects were observed with i.p. administration of the pGelonin/HPEI complexes. Our data indicate that HPEI nanogel-delivered pGelonin may have promising applications against human ovarian cancer.