长效避孕皮下埋植剂体外缓释行为研究

本文对以加成型硅橡胶为基质的左旋18—甲基炔诺酮长效避孕埋植剂的体外释放行为及对可能影响其释放量的诸因素,进行了观察与研究,结果表明:此长效避孕皮下埋植剂的体外释药行为,符合零级释药动力学规律。释药量受控释膜厚度,控释膜交联密度及释药面积的影响。体外释放药物曲线无明显爆破峰。     

Fas及FasL和Caspase-3在青蒿琥酯诱导人胚肺成纤维细胞凋亡中的表达

背景:青蒿琥酯具有减轻肺纤维化的作用,但相关机制的研究罕见报道。 目的：探讨青蒿琥酯对人胚肺成纤维细胞凋亡的作用及其与Fas,FasL,Caspase-3表达的关系。 方法：用1,10,100 mg/L青蒿琥酯分别干预体外培养的人胚肺成纤维细胞。采用CCK-8法检测青蒿琥酯对人胚肺成纤维细胞增殖的影响,流式细胞术测定细胞凋亡率,RT-PCR法测定Fas,FasL,Caspase-3 的mRNA的表达。 结果与结论：青蒿琥酯呈浓度依赖性抑制人胚肺成纤维细胞增殖,细胞经青蒿琥酯作用后凋亡率明显增加(P  < 0.05或P  < 0.01),Fas,FasL,Caspase-3 mRNA的表达显著高于对照组(P < 0.05)。结果证实,青蒿琥酯可通过上调Fas,FasL,Caspase-3 mRNA的表达抑制人胚肺成纤维细胞增殖、并促进细胞凋亡,发挥抗肺纤维化作用。     

青蒿琥酯对曼氏血吸虫雌虫生殖作用的影响

目的 :通过观察青蒿琥酯对曼氏血吸虫雌虫产卵的影响 ,分析药物的抗生殖作用。方法 :小鼠尾部接触感染曼氏血吸虫尾蚴后口服不同剂量青蒿琥酯 ,灌流后收集虫体 ,记数。解剖小鼠取出肝、肠 ,组织溶解后计数虫卵 ,分析药物作用后雌虫平均产卵量的变化 ;收集无损虫体进行体外培养 ,计数雌虫体外产卵并观察虫卵形态。结果 :在 30 0mg kg和 5 0 0mg kg给药组小鼠的肝、肠中未查到虫卵 ,10 0mg kg给药组小鼠的雌虫平均产卵量与对照组存在极显著性差异 ;体外培养结果中 ,30 0mg kg和 5 0 0mg kg给药组的虫体未见产卵 ,10 0mg kg给药组雌虫平均产卵量与对照组存在显著差异。显微观察发现 10 0mg kg给药组雌虫体外培养所产的虫卵多外附泡状物 ,侧棘受损 ,虫卵结构异常。结论 :青蒿琥酯能降低或完全抑制存活雌虫的平均产卵量、导致雌虫异常卵的产生 ,具有抗曼氏血吸虫雌虫生殖的作用 ,能有效预防曼氏血吸虫病的发生和传播     

青蒿琥酯通过调控PI3K/Akt信号通路抑制肝癌细胞增殖促进凋亡

目的 探讨青蒿琥酯对人肝癌细胞系HepG2的增殖和凋亡的影响及可能机制.方法 体外培养人肝癌细胞系HepG2,分别用浓度为12.5、25、50、100mg/L青蒿琥酯作用不同时间后,采用CCK-8实验检测细胞增殖情况;随后选择最佳浓度的青蒿琥酯作用HepG2细胞24h后,流式细胞术检测细胞凋亡,Western blot检测Bax、Bcl-2、PI3K、p-PI3K、Akt和p-Akt的水平.结果 不同浓度的青蒿琥酯处理细胞24h后,青蒿琥酯均能显著抑制肝癌细胞HepG2的增殖,且该作用呈现剂量依赖性.流式细胞仪检测发现青蒿琥酯能显著促进肝癌细胞HepG2的凋亡,同时Western blot也进一步证实,青蒿琥酯处理后HepG2细胞中的抑凋亡蛋白Bcl-2显著下调,促凋亡蛋白Bax表达显著上调;同时发现青蒿琥酯能够降低p-PI3K和p-Akt的水平,但未磷酸化的PI3K和未磷酸化的Akt含量变化无显著性差异.结论 青蒿琥酯可以抑制肝癌细胞HepG2的增殖,促进细胞凋亡,该作用与调控PI3K和Akt的磷酸化水平密切相关.     

野生型PTEN基因增强青蒿琥酯抑制K562细胞的作用

 目的: 探讨野生型PTEN转染人白血病K562细胞系对青蒿琥酯敏感性的影响及其分子作用机制。方法: 将野生型PTEN以腺病毒为载体转染(感染复数为200)人白血病K562细胞(Ad-WT-PTEN),同时以转染空载体腺病毒(Ad)及未转染细胞为对照组,与青蒿琥酯(ART)联合作用,观察野生型PTEN增强青蒿琥酯抑制K562细胞的作用。根据IC₅₀计算PTEN对青蒿琥酯的增敏倍数。以四甲基偶氮唑蓝(MTT)法检测细胞活力,流式细胞术检测细胞凋亡率,real-time PCR检测PTEN 的mRNA水平,Western blot检测PTEN、蛋白激酶B(Akt)及磷酸化Akt(p-Akt)的蛋白水平;caspase活性检测试剂盒检测caspase-3/7的活性。结果: Ad-WT-PTEN转染K562细胞后,对青蒿琥酯敏感性明显增加,依据IC₅₀计算增敏倍数为2.25倍。至第3天,Ad-WT-PTEN +ART组较Ad+ART组细胞活力下降、凋亡率升高。Ad-WT-PTEN转染K562细胞后PTEN 的mRNA及蛋白表达明显增加,p-Akt水平及caspase-3/7活性下调,以PTEN及青蒿琥酯联合作用组下调尤为明显。结论: 野生型PTEN可能通过降低K562细胞Akt磷酸化的水平,并增加caspase-3/7活性,增强细胞对青蒿琥酯的敏感性。     

青蒿琥酯抑制红系造血的机理研究

本研究从血红素生物合成途径探讨了青蒿琥酯抑制红系造血的机理。用荧光分光光度测定了犬和大鼠口服青蒿琥酯后外周血红细胞游离原卟啉(FEP)含量变化,并对犬外周血及骨髓涂片进行铁染色细胞化学观察,对犬骨髓幼红细胞还进行了超微结构观察和X射线微区元素分析,此外还测定了青蒿琥酯钠对离体大鼠肝线粒体亚铁螫合酶活性的影响。结果表明,青蒿琥酯可使犬和大鼠外周血红细胞游离原卟啉含     

青蒿琥酯调节PERK/ATF4/CHOP信号通路对OGD/R诱导的心肌细胞铁死亡的影响

目的:探讨青蒿琥酯调节蛋白激酶R样内质网激酶(PERK)/激活转录因子-4(ATF4)/C/EBP同源蛋白(CHOP)信号通路对氧糖剥夺/复氧(OGD/R)诱导的心肌细胞铁死亡的影响。方法:体外培养大鼠心肌细胞H9c2构建OGD/R模型,通过CCK-8法检测0、1.0、2.5、5、10、20μmol/L青蒿琥酯处理24h后各组细胞活力,筛选合适的青蒿琥酯作用浓度。将体外培养H9c2细胞随机分为对照组、模型组、青蒿琥酯低剂量组、青蒿琥酯高剂量组、MK-28(PERK激活剂)组、青蒿琥酯高剂量+MK-28组,除对照组外的其余各组细胞构建OGD/R模型,然后马上使用青蒿琥酯和MK-28分组处理,采用CCK-8法和流式细胞术分别检测各组H9c2细胞活力和凋亡率;ELISA检测各组H9c2细胞培养基上清中心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)、肌红蛋白(MB)、炎性因子[前列腺素E2(PGE2)、环氧化酶-2(COX-2)、白细胞介素(IL)-1β]水平;化学荧光法检测活性氧(ROS)水平,微量法检测铁含量、丙二醛(MDA)水平,微板法检测谷胱甘肽(GSH)水平;免疫印迹实验检测各组H9c2细胞PERK/ATF4/CHOP通路相关蛋白表达。结果:与对照组比较,模型组细胞活力、GSH水平降低(P<0.05),凋亡率、细胞培养基上清中cTnI、CK-MB、MB、PGE2、COX-2及IL-1β水平、细胞ROS相对水平、铁含量、MDA水平、p-PERK/PERK及ATF4、CHOP蛋白表达升高(P<0.05)。与模型组比较,青蒿琥酯低剂量组、青蒿琥酯高剂量组细胞活力、GSH水平均升高(P<0.05),凋亡率、细胞培养基上清中cTnI、CK-MB、MB、PGE2、COX-2及IL-1β水平、细胞ROS相对水平、铁含量、MDA水平、p-PERK/PERK及ATF4、CHOP蛋白表达均降低(P<0.05);青蒿琥酯高剂量组细胞活力、GSH水平相较青蒿琥酯低剂量组进一步升高(P<0.05),凋亡率、细胞培养基上清中cTnI、CK-MB、MB、PGE2、COX-2及IL-1β水平、细胞ROS相对水平、铁含量、MDA水平、p-PERK/PERK及ATF4、CHOP蛋白表达较青蒿琥酯低剂量组进一步降低(P<0.05);MK-28组细胞活力、GSH水平降低(P<0.05),凋亡率、细胞培养基上清中cTnI、CK-MB、MB、PGE2、COX-2及IL-1β水平、细胞ROS相对水平、铁含量、MDA水平、p-PERK/PERK及ATF4、CHOP蛋白表达升高(P<0.05)。与青蒿琥酯高剂量组比较,青蒿琥酯高剂量+MK-28组细胞活力、GSH水平降低(P<0.05),凋亡率、细胞培养基上清中cTnI、CK-MB、MB、PGE2、COX-2及IL-1β水平、细胞ROS相对水平、铁含量、MDA水平、p-PERK/PERK及ATF4、CHOP蛋白表达升高(P<0.05)。结论:青蒿琥酯可通过抑制PERK/ATF4/CHOP信号激活而抑制OGD/R诱导的心肌细胞炎症、铁蓄积和脂质过氧化,减轻铁死亡,增强其细胞活力,缓解细胞损伤。     

青蒿琥酯对人骨髓瘤细胞抗血管生成的作用

目的:研究青蒿琥酯对人RPMI-8226细胞诱导血管新生的抑制作用。方法:采用MTT法检测青蒿琥酯对RPMI-8226细胞增殖抑制作用;通过鸡胚绒毛尿囊膜体内血管生长实验,观察青蒿琥酯对RPMI-8226细胞诱导体内血管生成的影响;免疫蛋白印迹检测鸡胚绒毛尿囊膜内血管内皮生长因子(VEGF)和血管紧张素1(Ang-1)含量的表达变化。结果:青蒿琥酯以时间、剂量依赖方式抑制RPMI-8226细胞增殖;24h和48h后,其IC50值分别为(36.33±2.65)μmol/L和(14.31±3.28)μmol/L。在鸡胚绒毛尿囊膜体内血管生长实验中,经3、6、12μmol/L青蒿琥酯处理后,与单纯RPMI-8226细胞组比较,新生血管数目分别减少21.9%、38.2%和76.9%,差异有统计学意义;同时鸡胚绒毛尿囊膜内VEGF含量分别显著下降22.2%、34.2%和52.6%;Ang-1蛋白表达量分别显著下降15.6%、24.2%和39.6%。结论:青蒿琥酯具有抑制RPMI-8226细胞诱导血管新生的作用,其作用机制与下调RPMI-8226细胞的VEGF和Ang-1表达有关。     

青蒿琥酯对人肝癌HepG2细胞增殖和凋亡的影响及联合化疗药物的抗肝癌效应

目的: 研究青蒿琥酯对人肝癌HepG2细胞增殖和凋亡的作用,并检测其是否影响HepG2细胞对化疗药物的敏感性。方法: 采用CCK-8法观察不同浓度青蒿琥酯对HepG2细胞生长增殖的影响;克隆形成实验检测青蒿琥酯对HepG2细胞克隆形成的影响;Hoechst 33258染色观察青蒿琥酯作用HepG2细胞后细胞形态的变化;PI单染流式细胞术检测青蒿琥酯对HepG2细胞周期以及亚二倍体率的影响;Annexin V-PI双染测定青蒿琥酯对HepG2细胞凋亡的影响;CCK-8法检测青蒿琥酯对HepG2细胞化疗药物敏感性的影响。结果: (1)青蒿琥酯作用于HepG2细胞48 h后,能有效抑制其增殖,随着浓度的升高,增殖抑制率越高,IC₅₀值为19.2 μmol/L。(2)青蒿琥酯作用HepG2细胞7 d后,能有效抑制HepG2细胞形成的克隆数。(3)青蒿琥酯作用于HepG2细胞48 h后,Hoechst 33258染色可见实验组细胞胞核固缩、边聚和裂解、凋亡小体形成等凋亡形态学变化。(4)青蒿琥酯作用于HepG2细胞48 h后,PI单染流式细胞术检测细胞周期发现实验组细胞明显阻滞于G₂期。(5)青蒿琥酯作用于HepG2细胞48 h后,PI单染实验检测实验组出现明显的亚二倍体凋亡峰;Annexin V-PI 双染实验检测实验组细胞出现明显的早期凋亡细胞群。(6)青蒿琥酯分别联合化疗药物5-氟尿嘧啶、卡铂和表柔比星作用于HepG2细胞48 h后,能明显增强化疗药物对肿瘤细胞的抑制作用,增敏倍数分别为3.33、2.02和1.71。结论: (1)青蒿琥酯对人肝癌HepG2细胞有增殖抑制作用,并诱导其凋亡。(2)青蒿琥酯能提高人肝癌HepG2细胞对5-氟尿嘧啶、卡铂和表柔比星的敏感性。     

诱导细胞凋亡青蒿琥酯抗食管癌作用机制研究

 [摘要] 目的 研究青蒿琥酯诱导食管癌细胞凋亡作用及探讨青蒿琥酯抗食管癌作用机制。方法 不同浓度的青蒿琥酯(Artesunate, Art)(0、10、20、40μg/ml) 作用Eca109细胞24h,流式细胞术（Flow cytometry, FCM）方法检测细胞凋亡、周期及细胞中bcl-2和bax蛋白的表达量。结果 青蒿琥酯作用Eca109细胞24h后,与对照组相比,细胞凋亡率显著增高P<0.05,且具有剂量依赖性。青蒿琥酯组与对照组相比,Eca109细胞中bcl-2蛋白表达水平及细胞增殖指数显著降低P<0.05,而bax蛋白表达量显著增高P<0.05,且具有剂量依赖性。结论 青蒿琥酯可以通过调节Eca109细胞中bcl-2、bax蛋白表达水平和细胞增殖,从而诱导Eca109细胞产生凋亡,起到抗食管癌作用。     

In vitro and in vivo antimicrobial activity of covalently coupled quaternary ammonium silane coatings on silicone rubber

Biomaterial-centered infection is a dreaded complication associated with the use of biomedical implants. In this paper, the antimicrobial activity of silicone rubber with a covalently coupled 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) coating was studied in vitro and in vivo. Gram-positive Staphylococcus aureus ATCC 12600, Staphylococcus epidermidis HBH, 102, and Gram-negative Esherichia coli O2K2 and Pseudomonas aeruginos AK1 were seeded on silicone rubber with and without QAS-coating, in the absence or presence of adsorbed human plasma proteins. The viability of the adherent bacteria was determined using a live/dead fluorescent stain and a confocal laser scanning microscope. The coating reduced the viability of adherent staphylococci from 90% to 0%), and of Gram-negative bacteria from 90% to 25% while the presencc of adsorbed plasma proteins had little influence. The biomaterials were also subcutaneously implanted in rats for 3 or 7 days, while pre- or postoperatively seeded with S. aureus ATCC 12600. Preoperative seeding resulted in infection of 7 out of 8 silicone rubber implants against 1 out of 8 QAS-coated silicone rubber implants. Postoperative seeding resulted in similar infection incidences on both implant types, but the numbers of adhering bacteria were 70% lower on QAS-coated silicone rubber. In conclusion, QAS-coated silicone rubber shows antimicrobial properties against adhering bacteria, both in vitro and in vivo.     

In vivo tissue reactivity of radiation-cured silicone rubber implants.

Silicone rubber implants are clinically used in large numbers and elicit a milk tissue reaction. An occasional patient develops an accentuated reaction, an observation which has stimulated clinicians to try to understand this process more fully. The chemistry of medical silicone implants, including quantitative composition, is reviewed. This in vitro laboratory study show less tissue reaction-cured silicone with SiO2 filler. A proposed system for fabrication and curing of a silicone implant, with the qualities of strength and diminished tissue reactivity, is discussed.     

Utilization of the platelet release reaction in the blood compatibility assessment of polymers

The release reaction is directly associated with platelet adhesion and aggregation, which are primary events leading to thrombus formation following contact of blood with artificial surfaces. This investigation examined the release reaction from the alpha granules of platelets after blood-polymer interaction, and utilized the measurement of beta-thromboglobulin (BTG), a platelet-specific protein, in the assessment of the in vitro blood compatibility of polymers. A radioimmunoassay was used, to determine the release of BTG following contact of blood with tubes of siliconized glass and polypropylene and flat sheets of poly(vinyl chloride) and silicone rubber. Polypropylene tubes caused less release of BTG than those of siliconized glass and silicone rubber induced less BTG release than poly(vinyl chloride). The investigation indicates a role for BTG measurement in blood compatibility assessment.     

引导组织生长硅橡胶人工颅骨的研制及皮下植入试验

为减少颅骨修补术后皮下积液及响颅综合症的发生 ,研制一种新型引导组织生长硅橡胶人工颅骨。通过模压方法制备硅橡胶颅骨 ,采用硅橡胶粘合剂在颅骨的外表面复合聚酯无纺布 ,并进行了物理、化学性能和生物安全性评价。家兔皮下种植实验表明 ,聚酯无纺布具有显著诱生组织细胞爬生作用 ,引导组织生长硅橡胶人工颅骨是一种安全、可靠的颅骨修复用品     

Histological biocompatibility of new, non-absorbable glaucoma deep sclerectomy implant

We performed this study to compare the intrascleral biocompatibility of three materials: non-absorbable hydrogel contact lens polymer, non-absorbable silicone rubber, and absorbable cross-linked sodium hyaluronate. Intrascleral implantation of three different materials was performed in 13 healthy, pigmented rabbits. Implants of methacrylic hydrogel, silicone rubber, and cross-linked sodium hyaluronate were implanted in 10, 8, and 8 eyes, respectively. The animals were euthanized at 7, 30, 180, and 360 days post implantation. The eyes were enucleated and immediately fixed in 10% buffered formalin. Semithin sections were cut and stained with hematoxylin-eosin. Light microscope analysis of the specimens was performed. The least severe inflammatory reaction was observed with cross-linked sodium hyaluronate implants. The number of inflammatory cells in proximity to methacrylic hydrogel and silicone implants at all periods of follow up was similar. The thickest fibrous capsule was observed with silicone implants (average, 28.38 +/- 11.17 microm). This area was thinner with methacrylic hydrogel implants (average, 14.90 +/- 5.57 microm) and was thinnest around sodium hyaluronate implants (average, 7.21 +/- 2.33 microm). For each type of implant, the wall on the conjunctival side of the fibrous capsule was significantly thicker than the wall on the choiroidal side. The space between the implant, scleral flap, and bed was filled soon after surgery with connective tissue rich in vessels. In our study, cross-linked sodium hyaluronate had the highest intrascleral biocompatibility. Although the inflammatory responses of the sclera to methacrylic hydrogel and silicone rubber were similar in nature, a thicker fibrous capsule was generated around silicone implants.     

抗肿瘤药物长春新碱控制释放剂型的研究

肿瘤是危害人体生命健康的常见病,多发病。目前,化疗仍为治疗肿瘤的主要方法。全身用药有一定疗效,但存在患病部位抗肿瘤药物浓度不高,全身副作用较大等弊端。我们采用生物可降解材料胶原作为载体制备可控制抗肿瘤药物释放系统,然后植入患者体内,可以达到提高局部药物浓度,减轻毒副作用,并可使药物达到缓解的目的,为治疗肿瘤提供了一个新的途径[1]。1　材料及方法1.1　原料长春新碱(VCR),杭州民生制药厂;胶原溶胀液(固含量1.39%),中国医学科学院生物医学工程研究所;丙二酸,中国上海南翔试剂厂;阿拉伯胶,上海化学试剂采购供应站试剂厂;明胶…     

纳米铁显影增强硅橡胶的制备及影像可视性评价

目的 探讨纳米铁微粒作为显影标记物对医用硅橡胶改性的可行性并评价复合材料的影像可视性.方法 硅油与纯铁粉、碳包铁粉混合,按预定的配方比分别与甲基乙烯基硅橡胶共混、密炼、模压、硫化,得到纳米纯铁粉增强硅橡胶（第1组）、纳米碳包铁粉增强硅橡胶（第2组）,空白对照组为医用硅橡胶.CT扫描体外各组材料试件,获取图像并测得CT值,比较组间CT值均值的差异性;将2组材料试件植入犬皮下,获得标准X-线图像;X射线衍射技术分析材料内铁微粒的组分稳定性.结果 分别制备出铁粉显影增强硅橡胶和碳包铁粉显影增强硅橡胶,新材料在体内外的X-线图像清晰可见,复合材料的CT值随金属纳米粉体量和纳米微粒原子量的增加而增加,2组材料的CT值均值、组间配方比相同的材料的CT值均值差异显著（P＜0.001）;材料放置180 d后,单质铁出现衍射峰的位置基本没有变化,分散在硅橡胶中的纳米纯铁微粒、碳包铁微粒较为稳定.结论 金属纳米铁粉、碳包铁粉可作为硅橡胶显影性改良的标记物.     

The effect of self-assembled layers on the release behavior of rifampicin-loaded silicone

Providing a long period of sustained antibiotic release is one of the important challenges in the development of clinical shunts for long-term implantation. A cast-molding approach was used to load rifampicin into the silicone precursor before curing. Sustained in vitro release from rifampicin-loaded silicone for upwards of 110 days at a level of approximately 2-4 microg/cm2 per day was achieved. Quantitative comparisons of Staphylococcus epidermidis adhesion on untreated and rifampicin-loaded silicone surfaces were carried out to demonstrate the effect of rifampicin to discourage the bacterial adhesion. It was shown that the fresh 8.3% rifampicin-loaded silicone decreased bacterial adherence by 99.8%. Bacterial adherence on rifampicin-loaded silicone surfaces after 90 days release (eluted silicone) was decreased by 94.8%. A new approach was used to tune the initial burst effect and prolong long lasting release by introducing self-assembled perfluorodecyltrichlorosilane (FAS) and octadecyltrichlorosilane (OTS) layers. FAS layered structures can tune the burst effect and prolong the subsequent continuous release to achieve the long-term delivery. Significant decreases in initial burst effect (70.3% for multi-FAS layers and 39.7% for FAS monolayer) and enhanced long-term release (approx. 10 microg/cm2 per day for FAS monolayer for 110 days and approx. 15 microg/cm2 per day for multi-FAS layers for 60 days) were observed.     

Silicone rubber-hydrogel composites as polymeric biomaterials. I. Biological properties of the silicone rubber-p(HEMA) composite

A composite material was prepared consisting of silicone rubber matrix and particulate lightly cross-linked poly(2-hydroxyethyl methacrylate) (p(HEMA] hydrogel. The material resembling common silicone rubber is hydrophilic and swells in water like hydrogels. The effects of the implanted composite on tissues of the living organism were tested in rats by methods assessing local acute and chronic inflammatory reactions and calcification by means of radioactive indicators and by histological examination. Results of a 6 month implant study indicated no difference in reactions of the animal body on the silicone rubber-p(HEMA) composite and a non-toxic, non-irritant pure solid p(HEMA) control.