抗凝血纳米壳聚糖微球的合成、表征及生物安全性评价

 背景：有研究显示,壳聚糖等天然多糖经磺化改性后具有类似肝素的抗凝功能,因磺酸化后的壳聚糖其形成的磺酸根基团与肝素的活性基团相似,具有良好的抗凝血性。 目的：制备具有抗凝血功能的纳米壳聚糖微球,检测其形态结构、理化性能及生物安全性。 方法：利用乳相法合成纳米壳聚糖微球,通过磺化反应合成磺酸化壳聚糖微球,通过透射电镜描述其形态特征,红外光谱观察其特异基团峰值变化。①凝血实验：分别将肝素、纳米壳聚糖微球及10,30,50 mg磺酸化壳聚糖微球加入SD大鼠血中,检测凝血指标。②溶血实验：分别将去离子水、生理盐水及10,30,50 g/L磺酸化壳聚糖微球浸提液加入兔2%红细胞悬液中,检测溶血率。③细胞毒性实验：分别采用含体积分数10%胎牛血清的DMEM培养基及10,30,50 g/L磺酸化壳聚糖微球的浸提液培养人脐静脉血管内皮细胞,72 h后检测细胞相对增殖率及毒性分级。 结果与结论：扫描电镜显示磺酸化壳聚糖微球具有良好的形态结构,粒径大小50 nm,红外图谱提示存在磺化取代。体外凝血实验表明磺酸化壳聚糖微球具有显著抗凝血作用,抗凝血效果呈剂量效应关系。磺酸化壳聚糖微球符合国标关于溶血率小于5%的安全标准,无致溶血性。细胞毒性实验表明磺酸化壳聚糖微球浸提液无明显细胞毒性,其生物安全性符合国家标准。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

壳聚糖载氟喹诺酮类药物缓释微球的研究进展

壳聚糖载氟喹诺酮类药物微球是一类新型的抗菌缓释剂,它既具有壳聚糖的抗菌、抑菌性能,又能发挥氟喹诺酮类药物良好的杀菌作用.将氟喹诺酮类药物负载于壳聚糖微球,可大幅提升其抗菌、杀菌及消炎抗感染性能.综述了近几年壳聚糖载氟喹诺酮类药物缓释微球的制备方法及其应用研究进展.     

接种缓释霍乱微球疫苗的试验研究

把霍乱弧菌Ｉｎａｂａ５６９Ｂ株的外膜蛋白（ＯＭＰ）包入可生物降解的聚乳酸－聚乙二醇共聚体内，制备成缓释微球疫苗。对微球在动物体内的靶向分布研究，表明口服微球后主要分布在肝、脾和肠系膜淋巴结等部位。采用微球疫苗免疫ＢＡＬＢ／ｃ小鼠后，收集其唾液、血清和粪便，采用ＢＡ－ＥＬＩＳＡ法检测了ｓＩｇＡ和ＩｇＧ抗体滴度。在第６周，口服微球疫苗组的小鼠粪便ｓＩｇＡ滴度比口服游离ＯＭＰ对照组高５倍；在第１２周时ｓＩｇＡ高达１０倍（２２４／２２），同时小鼠血清ＩｇＧ滴度也比对照组高１４倍（１９２０／１４０）。采用霍乱弧菌经腹腔攻击免疫小鼠后，发现口服微球疫苗组保护率为５０％～７０％，皮下注射微球疫苗组保护率为８０％～１００％，而口服游离ＯＭＰ组保护率仅为１０％。     

强的松龙纳米微球缓释膜制备及缓释特性

背景:近年来将强的松龙应用于促进周围神经损伤后功能恢复取得了良好效果,但因半衰期短、局部应用血药浓度不稳定及较大的不良反应限制了其临床应用。目的:制备强的松龙纳米微球缓释膜并对其药物缓释特性进行检测。方法:采用反胶束乳化溶剂挥发法制备强的松龙纳米微球,对载药纳米微球的形态、粒径、载药量、包封率和体外释药行为等性质进行研究;同时将纳米微球与胶原、壳聚糖、大豆卵磷脂等膜材相结合,制得复合药膜,考察复合药膜的形貌、膜中材料的相互作用及药膜的体外释药行为。结果与结论:强的松龙纳米微球具有良好的微观结构,药物均匀分布于纳米微球中,纳米微球粒径均一,表面光滑,平均粒径500 nm,包封率达90%以上,体外缓释实验药物释放良好,存在一定的药物突释现象。观察球膜结合方法制得的复合膜,可见纳米微球均匀分散于复合膜中,复合膜微观结构良好,体外缓释实验见复合膜药物释放更加稳定,无明显药物突释现象出现,显示了良好的药物释放效果。表明通过反胶束乳化溶剂挥发法和球膜结合方法制备出的强的松龙缓释膜剂具有良好的药物缓释特性。     

注射用雌二醇聚乳酸羟基乙酸缓释微球生物相容性研究

目的：以整体动物为研究对象，考察注射用雌二醇聚乳酸羟基乙酸缓释微球动物体内的生物降解和生物相容性。方法：肌注给药，显微镜观察组织切片，研究空白PLGA微球及载雌二醇PLGA微球的生物降解和相容性。结果：28d内，微球从规则球形降解为不规则微小颗粒，组织学观察空白微球和载雌二醇微球均未见病理改变。结论：注射用雌二醇聚乳酸羟基乙酸缓释微球具有良好的生物降解和相容性。     

两性霉素B缓释微球的制备及缓释性能研究

为了更好地研究药物载体材料对药物微球缓释性能的影响,本研究将可完全生物降解的共聚物作为壁材以相分离法制备含抗真菌药物两性霉素B的微球,研究了不同溶剂/非溶剂、不同分子量共聚物、不同配比共聚物、不同表面活性剂及其不同用量等因素对微球的粒径大小、分布、药物包封率和药物体外释放等性能的影响。使用透射电镜（TEM）和原子力显微镜（AFM）观察微球的表面形貌,使用激光粒度分析仪测试微球的粒径大小及分布,使用紫外分光光度计测定药物的包封率。研究发现,聚合物特性粘度和分子量越大,聚合物中LA：PEG的配比越大,微球粒径越大,分布越宽;微球粒径越大,包封率也较大;AmB/PLA-PEG微球具有缓释性能,且含药微球的释放性能与微球的粒径,包封率等因素有关。     

纳米微球负载抗生素/羟基磷灰石复合支架的缓释性能及治疗感染性骨缺损的研究

目的 评价新型纳米微球负载抗生素/羟基磷灰石复合支架材料的体外缓释性能及治疗感染性骨缺损的疗效。方法 运用HPLC法检测不同时间点药物的体外释放量。建立兔胫骨感染性骨缺损动物模型24只,共分为4组：a组动物仅单纯清创;b组植入1 mg Lev/PMMA;c组植入n-HA/PU;d组植入1 mg Lev/n-HA/PU。在植入材料术后6周、12周观察放射学、组织病理学,Micro CT评价新骨生成。评价新型复合材料控制感染、诱导成骨能力、治疗感染性骨缺损的效果。结果 1 mg Lev/n-HA/PU组比1 mg Lev/PMMA组释放的抗生素更多（P<0.05）,缓释性能表现更好。单纯清创组X线表现出局部骨破坏、死骨形成。1 mg Lev/n-HA/PU组无明显骨破坏。Micro CT发现1 mg Lev/n-HA/PU组材料周围新生骨小梁数量与其余三组比较,差异有统计学意义（P<0.05）,结论 新型载抗生素复合支架材料具有良好的缓释性能、抗感染能力、骨诱导能力,可有效治疗胫骨感染性骨缺损。     

丝素蛋白纳米羟基磷灰石复合材料的生物安全性

BACKGROUND: Silk fibroin has excellent biocompatibility, biodegradability and unique mechanical properties. Its composite, silk fibroin/nano-hydroxyapatite, can simulate the composition and structure of nature bone tissue, contributing to remedying the insufficient mechanical properties of nano-hydroxyapatites. OBJECTIVE: To observe the biological safety of silk fibroin/nano-hydroxyapatite composites. METHODS: Silk fibroin/nano-hydroxyapetite composite biomaterial was synthesized by the coprecipitation method using silk fibroin, calcium chloride and diammonium phosphate as raw materials. According to the demands of International Standard Organization (ISO10993) and Technical Evaluation Standards of Biomedical Materials and Medical Instruments promulgated by Chinese Board of Health (GB/T 16886), experiments of cell toxicity in vitro, acute toxicity and hemolysis were investigated to evaluate the biocompatibility of silk fibroin/nano-hydroxyapetite composite. RESULTS AND CONCLUSION: L929 cells co-cultured with silk fibroin/nano-hydroxyapatite composite leaching liquor had good cell morphology, metabolism and proliferation. The leaching extract of silk fibroin/nano-hydroxyapatite composite injected into mice intraperitoneally had no significant adverse reactions. And silk fibroin/nano-hydroxyapatite composite extracts caused 2.39% blood hemolysis, less than the international standards 5%. These experimental results on cell toxicity test in vitro, acute toxicity and hemolysis met the demands of ISO10993 and GB/T, which show the biological safety of the silk fibroin/nano-hydroxyapatite composite for clinical application.     

评价纳米生物材料安全性的研究进展

由于纳米生物材料独特的物理化学性质，将被人们广泛应用于材料、化妆品、医药等众多领域。使研究者、生产者和消费者今后将有许多机会接触纳米生物材料。特别是在医药卫生领域应用时与人体密切相关，纳米生物材料的安全性格外引起了各方面的关注和争论。文中综述了国内外对纳米生物材料安全性评价的研究进展，并综述了纳米生物材料在体内转移的途径，最后提出在纳米技术形成产业之前，人类应有机会了解其对环境和人类健康的影响，因此对纳米生物材料的安全性评价进行深入研究已经成为当务之急。     

纳米羟基磷灰石生物安全性评价与研究进展

国内外大多数研究显示羟基磷灰石具有良好的生物相容性和生物活性,医学领域的运用中,普通羟基磷灰石的缺点是脆性大,有很多研究显示纳米羟基磷灰石有更高的强度和韧性,纳米羟基磷灰石晶体在形态、尺寸、组成、结构和结晶度上与人骨羟基磷灰石晶体高度类似,因此纳米羟皋磷灰石在医学领域的应用也日益广泛。对纳米羟基磷灰石生物安全性的评价不断取得进展,大量研究认为纳米羟苯磷灰石具备生物安全性,但是作为一种新型生物材料,纳米羟基磷灰石在评价标准方面有一些问题。     

D,L-聚乳酸基形状记忆聚合物的生物安全性和细胞相容性

背景：课题组前期实验研制了输卵管避孕器材料D, L-聚乳酸基形状记忆聚合物,依据国内《生物材料和医疗器材生物学评价技术要求》规定,植入体内的组织工程材料必须进行生物安全评价和细胞相容性实验。 目的：观察D, L-聚乳酸基形状记忆聚合物的生物安全性。 方法：①内毒素实验：在鲎试剂中分别加入聚合物浸提液、内毒素工作标准品溶液和细菌内毒素检查用水。②致敏实验：在昆明小鼠肩胛骨内侧分别注射聚合物浸提液+弗氏完全佐剂+生理盐水、弗氏完全佐剂+生理盐水,通过皮内诱导、局部诱导和激发阶段,观察动物激发部位皮肤红斑和水肿反应程度。③急性毒性实验：分别在昆明小鼠腹腔注射100%,50%,25%聚合物浸提液及生理盐水。④细胞增殖MTT实验：直接法为将人脐静脉内皮细胞分别接种于聚合物膜、聚乳酸与玻璃片上;间接法为将人脐静脉内皮细胞分别接种于聚合物浸提液、丙烯酰胺溶液及1640培养液。 结果与结论：D, L-聚乳酸基形状记忆聚合物材料无细菌污染状况,符合生物安全标准,无致敏性及毒性,并且具有较好的细胞相容性。     

Results of tests for micronuclei and chromosomal aberrations in mouse bone marrow cells with the human carcinogens 4-aminobiphenyl, treosulphan, and melphalan

Three human carcinogens, 4-aminobiphenyl, treosulphan, and melphalan, were tested for the induction of micronuclei or chromosomal aberrations in the bone marrow cells of male B6C3F1 mice. These studies were conducted to provide further information on the in vivo genetic toxicity of compounds known to cause cancer in humans. All three compounds gave positive results in the mouse bone marrow micronucleus test, and melphalan, the only compound tested for aberration induction, was positive in this assay. These results extend the evidence that nearly all known human carcinogens are detected in relatively simple and widely employed short-term in vivo tests.     

Surgical Removal of lipoma from an area with tattooed skin

The presence of tattoos on the skin of people of all ages is on the rise. On occasion, the tattoo is in close proximity to an area which has to undergo a surgical operation, therefore why not using the tattoo itself to cover the cicatrix?The case we treated was that of a 39 year old female who, for a couple of years, had a large lipoma on her right shoulder which she never treated because it was beneath a large tattoo. During the surgical treatment of the lipoma, we followed the exact lines of the tattoo itself thus obtaining precise access for lipoma removal which minimized visible post operative cicatrix while maintaining the original tattoo design.No similar case was found in literature.     

Cyclosporine A disposition,hepatic and renal tolerance in Wistar rat

Cyclosporine A, a potent calcineurin inhibitor, has been widely used in organ transplantation and in the treatment of autoimmune diseases. It has, however, been shown to induce serious renal and hepatic side effects. The drug is also used in preclinical studies, but with little published information on the optimal dose and route of administration in rodents. Objectives of this study were to identify efficient and safe doses of cyclosporine A in rodent and to assess its effects on hepatic and renal functions. For this purpose, we tested the effects of different doses and administration routes of cyclosporine A (5, 2.5 and 1?mg/kg) administered during 28 days intraperitoneally, or by gastric feeding on Wistar rats. Our data indicate that rats injected intraperitoneally with 5?mg/kg/2d (every two days) exhibited trough cyclosporine A levels within known therapeutic range in human, but were subject to blood cyclosporine A accumulation, whereas the 5?mg/kg/d gavage resulted in only a small cyclosporine A accumulation over time. In both cases this accumulation was not deleterious to renal and hepatic functions, as shown by transaminase, urea, creatinine and bilirubin measurements.     

Use of bilidase for the treatment of experimental hypertrophic postburn cicatrices

The efficiency of bilidase (hyaluronidase preparation) was studied in guinea pigs with experimental postburn cicatrices. Bilidase promoted normalization of the structure and histochemical picture of new cicatricial tissue. The drug can be used for the treatment of hypertrophic postburn cicatrices.__________This revised version was published online in July 2005 with the addition of the issue titleTranslated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 1, pp. 113–115, January, 2005     

两种寰椎侧块螺钉固定方法的可行性比较

背景：寰椎侧块螺钉固定技术按其入钉点的不同可分为寰椎后弓下侧块螺钉固定和经寰椎后弓侧块螺钉固定(又称寰椎椎弓根螺钉固定),这2种固定方法各有优缺点,以往缺乏关于2种寰椎侧块螺钉固定方法骨性解剖可行性的比较研究, 目的：以测量国人寰椎相关骨性解剖数据为依据,比较2种寰椎侧块螺钉固定方法的可行性。 方法：收集30例(60侧)成人颈椎病患者的寰椎螺旋CT扫描数据,利用CT工作站对数据重建,分别测量寰椎侧块螺钉固定的关键骨性解剖数据,适合行经寰椎后弓侧块螺钉固定的标准为寰椎椎动脉沟处后弓高度和宽度≥ 4 mm;适合行经寰椎后弓下侧块螺钉固定的标准为寰椎后弓下侧块高度≥ 4 mm。 结果与结论：寰椎椎动脉沟处后弓高度为(4.54±1.17) mm,椎动脉沟处后弓宽度为(8.69±1.12) mm,寰椎后弓下侧块高度为(4.98±1.07) mm。寰椎后弓椎动脉沟高度大于4 mm(适合经寰椎后弓螺钉固定组)有41侧,占68%;寰椎后弓下侧块高度大于4 mm(适合经寰椎后弓下侧块螺钉固定)有52侧,占87%,2组差异有显著性意义(P < 0.05)。提示经寰椎后弓下侧块螺钉固定较经寰椎椎弓根螺钉更具可行性。术前利用CT测量寰椎关键解剖结构数据对制定个性化手术方案具有重要意义。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

Skin Morphology at the Site of Postoperative Cicatrix Formed after the Use of Different Surgical Cutting Instruments

Experimental morphological study of the postoperative cicatrix forming after the use of scalpel made from a crystal material was carried out. The skin healed much sooner and the resultant cicatrix was more fine in comparison with the wound inflicted by a common metal scalpel. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 146, No. 12, pp. 701–703, December, 2008     

Flow microfluorometric analysis of murine spermatozoa fails to detect H-2 antigens

The presence of class 1 and class 2 histocompatibility antigens on murine sperm was investigated by flow microfluorometry. Monoclonal anti-H-2Kk (class 1), anti-Iak (specificity 2, class 2) and allo-anti-Iak (class 2) antisera were used in direct or indirect fluorescence labelling experiments to probe the expression of class 1 and class 2 antigens on epididymal mouse spermatozoa. Sperm-specific antibodies were generated by intraperitoneal immunization of both male and female C3H/HeN mice with syngeneic spermatozoa. Sperm-specific antigens were detected in 68-85% of syngeneic mouse sperm and 65-90% of allogeneic mouse sperm examined. Conversely, these antibodies did not stain syngeneic or allogeneic lymphocytes above the background of the negative control. Mouse sperm samples failed to exhibit specific fluorescence above the background of negative control values with antibodies against either class 1 or class 2 MHC antigens. We have established the sensitive, objective and economical assay of sperm membrane antigens with fluorochrome-labelled antibodies by flow microfluorometry. By use of this sensitive and objective technique we have not detected MHC antigens on murine sperm. We conclude that these MHC antigens are not expressed on sperm at a level to be practically detectable.     

Adult onset spinocerebellar ataxia linked to HLA in a South African kindred of mixed ancestry

Hereditary spinocerebellar ataxia (SCA) is a relatively common disorder in the Western Cape region of South Africa. At present there are no genetic markers available for prenatal or presymptomatic diagnosis. A large kindred of mixed ancestry with late onset SCA was studied in which the disorder segregated in an autosomal dominant fashion. HLA typing was undertaken on 44 family members, and the HLA haplotypes were assigned on the basis of segregation. The LIPED computer program, with a correction factor allowing for the age of onset, was used to analyze the pedigree for linkage to HLA. Of 22 individuals in whom disease status could be definitely assessed, only one recombinant between HLA and the SCA locus occurred. The lod score reached a maximum of 4.13 at a recombination fraction of 0.05, indicating the odds to be approximately 13,500 to 1 in favor of linkage between HLA and the putative disease allele for SCA. A possible recombination within the HLA region suggested that the disease allele lies telomeric of the HLA region. In view of the recent demonstration of tight linkage between SCA1 and D6S89, however, HLA should not be used for presymptomatic diagnosis or genetic counselling.     

Conditions of differentiation of original memory cells and of enriched precursors of secondary cytotoxic T lymphocytes specific for the class I histocompatibility molecule

Laboratory of Immunochemistry, All-Union Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Trapeznikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 109, No. 3, pp. 278–280, March, 1990.