Effects of Parenteral Lipid Infusion on DNA Damage in Very Low Birth Weight Infants

Very low birth weight (VLBW) infants are known to have poorly developed antioxidant system and may be at increased risk for radical damage. Previous studies have reported higher levels of lipid peroxide products in lipid emulsion used for parenteral nutrition. To examine the direct effects of parenteral lipid infusion on DNA damage in VLBW infants, we measured urinary 8-hydroxydeoxyguanosine (8-OHdG) levels in VLBW infants before, during, and after the parenteral lipid infusion. In both the lipid-infused and lipid-free groups, urinary 8-OHdG excretion levels at 14 days old were significantly ( p <0.01) lower than those at 2 and 7 days old. However, there were no significant differences in urinary 8-OHdG excretion levels between the lipid-infused and lipid-free groups at 2, 7, and 14 days old. Our results suggest that parenteral lipid infusion does not cause oxidative DNA damage, but irrespective of the infusion DNA damage during the first week of life is enhanced when compared with 14 days after birth in VLBW infants.     

乳液法神经生长因子（NGF）电纺纤维的体外研究

目的：使用乳液法制备含有神经生长因子（NGF）的电纺纤维,研究其外观形貌和机械强度等物理性能,以及制备过程中NGF活性的变化,纤维中NGF的担载量和纤维体外释放动力学,评价其能否成为理想的神经修复材料,为进一步将NGF电纺纤维应用于周围神经修复奠定基础。方法：将NGF水溶液分散于PLLA溶液,通过W／O乳液法制备静电纺丝缓释纤维,对纤维的外观形貌等物理性能等进行表征,使用Elisa方法测定制备过程中NGF活性的保持以及体外释放动力学。结果：NGF电纺纤维具备类似细胞外基质（ECM）的良好外观形貌和一定的机械强度,其中NGF活性保持19．58％士6．05％,体外有效释放11天。结论：本文制备的乳液法NGF电纺纤维具备良好的物理性能,能够持续缓释有效剂量的NGF,适合作为神经修复材料进行进一步研究。     

静电纺丝制备担载神经生长因子的聚乳酸纤维的工艺研究

目的:研究担载神经生长因子(NGF)的聚乳酸纤维乳液法静电纺丝的制备工艺,从电压、溶液浓度等工艺条件进行探索,通过扫描电镜对纤维的形态结构进行观察,旨在找到最佳纺丝制备条件,并观察该条件下纤维的体外释放行为和细胞活性。方法:将NGF水溶液分散于聚乳酸(PLLA)溶液中,通过W/O乳液法制备静电纺丝纤维。分别从电压8 k V、10 k V、12 k V,浓度梯度90mg/m L、100 mg/m L、110 mg/m L进行静电纺丝纤维的制备,对纤维的形态等进行表征。使用ELISA对NGF体外释放动力学进行检测,用Alamer Blue试剂考察纤维释放液对于PC12悬浮细胞增殖的影响。结果:浓度和电压对电纺纤维制备影响很大。当浓度过大时,易堵塞纺丝喷头且纤维弯曲,过小时纤维粗细差异较大。电压过大或过小时纤维弯曲情况严重,甚至出现缠绕现象。当浓度为100 mg/m L,电压为10 k V时制备的乳液法静电纺丝聚乳酸纤维直径粗细均匀,具有较好形态。在该条件下的制备的纤维NGF体外有效释放13天,释放液可以促进PC12细胞的增殖。结论:担载NGF的聚乳酸纤维乳液法最佳静电纺丝制备条件为:PLLA溶液浓度100 mg/m L、电压10 k V,该条件下制备的担载NGF的聚乳酸纤维体外释放可累计释放13天,其释放液可有效促进PC12细胞的增殖,为进一步研究担载NGF的聚乳酸纤维导管奠定了一定的工艺基础。     

乳液法静电纺丝PLGA组织工程缓释纤维的研究

目的：研究Dextran对蛋白药物的释放影响。方法：将模型蛋白BSA溶解于多糖溶液中,通过W/O乳液法静电纺丝制备缓释纤维。采用MicroBCA法测定该纤维体外释放行为,采用SEC-HPLC检测制备前后蛋白的聚集程度,并与不含多糖的BSA纤维做对照。结果：添加Dextran以后蛋白的包封率由52.68%提高到63.92%,第一天突释不大于药物载量的15%,对蛋白单体的保持达到85%以上。结论：Dextran可以改善一般组织工程纤维中蛋白药物的释放,提高蛋白药物在制剂、贮存、释放过程中的稳定性,增加纤维的载药量。     

Biogenic capsules made of proteins and lipids

Multilayer biogenic capsules with a micrometer scale were fabricated by self-assembly of proteins and lipids at the interface of emulsion droplets. The optical microscopy images demonstrate that spherical capsules at a fluid interface have uniform walls and the dried capsules possess a high mechanical strength. The hollow shells obtained provide a novel class of assembly with encapsulating drug molecules based on the layer-by-layer technique.     

大鼠子宫内膜炎模型复制及其中西药复方乳剂治疗

目的人工复制大鼠子宫内膜炎模型;应用自制中西药复方乳剂对子宫内膜炎模型大鼠进行治疗。方法对实验大鼠子宫眼观病变、子宫内容物及单侧子宫指数进行检查,对实验大鼠子宫进行病理组织学检查。结果应用3％冰乙酸对大鼠子宫进行刺激,第4天对大鼠子宫接种混合病原菌,能够稳定复制大鼠子宫内膜炎模型;中西药复方乳剂能明显降低大鼠子宫内细菌浓度、种类及单侧子宫系数,能明显减轻子宫的病理变化。结论中西药复方乳剂对子宫内膜炎模型大鼠有良好的治疗作用。     

Generation of lipase-containing static emulsions in silicone spheres for synthesis in organic media

Because of the broad versatility of lipases as biocatalysts, interest has for some years been focused on the improvement of the economy of processes using these enzymes, especially by appropriate immobilisation. In this study, a method was developed to emulsify aqueous solutions of lipase A of Candida antarctica (CALA) and lipase of Thermomyces lanuginosa (TLL) in silicone elastomers yielding elastic beads. The persistent water-organic interface created by this static emulsion enabled an improved performance of the immobilised lipases due to the well known fact that from a kinetic point of view these enzymes show a higher efficiency in biphasic than in monophasic systems. The entrapped lipases catalysed the esterification of octanol and caprylic acid in hexane with an activity that, related to the free enzyme, was enhanced about 31-fold for CALA and 250-fold for TLL. Comparison to the activity of the same enzymes in sol–gels revealed that for CALA immobilisation in static emulsion was the only method yielding active biocatalysts, whereas activation of TLL was in the same range in static emulsion and sol–gels. However, apparent activity of TLL in static emulsion was considerably higher than in sol–gels due to the feasible high enzyme loading. The results indicate that immobilising lipases as static emulsion is a technique suitable for biotechnological application. Moreover, a transfer to enzymes of other classes seems possible.     

A Proposed Mode of Action of Oil-Based Formulations of a Microbial Herbicide

Formulation of some microbial herbicides in emulsions of vegetable oil can significantly reduce their dependency on long dew periods to allow infection and control of the host weed. Examination of leaves of Viola arvensis , by a range of microscopy techniques, after spraying with an oilin-water emulsion formulation of the potential microbial herbicide Mycocentrospora acerina , suggests that the effect arises as a result of inversion of water into both oil droplets on the leaf surface and oil that penetrates into the leaf tissue. This oil probably mixes with aqueous components from the leaf tissue and, in doing so, forms an invert emulsion. Wesuggest that this supplies the water required by the fungus to initiate and sustain growth so that infection can result.     

担载血管生长因子的乳液法纤维用于血管再生的研究

目的:制备担载血管生长因子(VEGF)的乳液法静电纺丝纤维膜,对其开展一系列表征,从而研究其血管再生的潜能。方法:通过W/O乳液法制备担载VEGF的静电纺丝纤维膜,并对其形态、力学性质进行表征。用VEGF ELISA分析方法对其体外释放动力学进行研究。运用CCK-8法检测乳液法静电纺丝纤维膜中VEGF的活性变化。结果:乳液法静电纺丝纤维膜呈现连通的三维网状结构,平均直径为1μm,模拟了细胞外基质(ECM),最大拉伸应力为3.03±0.66 M Pa,具有良好的抗拉伸能力,能够支持细胞的生长。乳液法纤维膜中VEGF在体外累积释放了14天,总释放量超过20000 pg,达到血管再生的有效浓度。CCK-8结果显示,乳液法纤维膜中的VEGF仍然保持较高的蛋白活性。结论:担载VEGF的乳液法静电纺丝纤维膜能够缓释出活性的蛋白,具有血管再生的潜能。