气相色谱法检测交联透明质酸中交联剂残留量

目的建立一种二乙烯基砜交联透明质酸中交联剂二乙烯基砜残留量的检测方法.方法采用气相色谱法检测二乙烯基砜残留量,色谱柱为HP-5毛细管色谱柱(Agilent 19091J-413:325℃:30m×320μm×0.25 μm),程序升温,采用FID检测器,载气为氮气.结果二乙烯基砜在1μg～50μg/g线性关系良好,线性相关系数r=0.9999,平均回收率为97.8%(RSD为2.6%,n=5).结论气相检测交联透明质酸中交联剂含量,结果准确,方法简单可靠,可用于交联透明质酸水凝胶产品质量控制.     

《整形手术用交联透明质酸钠凝胶》行业标准中交联剂含量的检测方法研究

目的 改进和优化YY/T 0962—2014《整形手术用交联透明质酸钠凝胶》行业标准中交联剂1,4-丁二醇二缩水甘油醚(1,4-butanediol diglycidyl ether,BDDE)含量的标准检测方法,为该标准的修订提供技术依据.方法 在气相色谱法中,为使BDDE更好地从凝胶内部释放出来,在测定之前增加样品的酶解处理步骤,并用乙酸乙酯对BDDE进行萃取.此外,在酶标仪检测法中研究透明质酸酶的影响,将透明质酸酶添加到标准溶液中,从而去除透明质酸酶对测定结果的影响.最后委托M、Q、X三家实验室对该方法进行验证,对同一批次样品进行BDDE含量测定,对数据结果进行双因子方差分析,以检验该方法是否具有可行性.结果 气相法专属性、精密度以及重复性良好,平均回收率为105.02％,相对标准偏差(relative standard deviation,RSD)为9.15％(n=6).酶标仪检测法精密度、重复性良好,BDDE浓度0.5～8μg/mL范围内,BDDE浓度和荧光强度有良好的线性关系,线性方程为y=36.89x+2.135(r=0.9989),检出限为0.106μg/mL,平均回收率为97.43％,RSD为8.22％;采用双因子方差分析,对M、Q和本课题组(Z)三家实验室的验证结果进行统计(P>0.05),认为不同实验室采用同一方法对同批次样品的交联剂含量测定结果不存在显著性差异.结论 对于整形手术用交联透明质酸钠凝胶中交联剂BDDE含量的测定,气相法操作简单快捷,可作为BDDE的日常测定方法;酶标仪检测法特异性更高,数据更为真实精确,可作为整形手术用交联透明质酸钠凝胶产品中交联剂含量的仲裁方法.     

荧光分光光度法检测交联透明质酸中交联剂残留量

目的 建立一种1,4丁二醇二缩水甘油醚(1,4-Butanediol diglycidyl ether,BDDE)透明质酸中交联剂BDDE的残留量的检测方法.方法 采用荧光分光光度法测定BDDE的残留量.BDDE与烟碱反应在激发光380nm作用下产生荧光,其荧光强度与BDDE的置成正比,用荧光分光光度计在波长为435nm处检测其强度.结果 BDDE在0.25ug/g ～ 8ug/g线性关系良好,线性相关系数r=0.9999,平均回收率为101.5％(RSD为0.9％).结论 测量结果准确,方法简单可靠,可用于交联透明质酸水凝胶产品质量控制.     

注射用聚乳酸和交联透明质酸钠凝胶的制备及性能研究

本研究对交联透明质酸钠凝胶的交联工艺以及和自制的聚乳酸微球的不同配比进行研究,成功制备了注射用美容凝胶。对不同交联度和不同配比的溶胀度、流变学、渗透压、动力粘度、稳定性等性能指标进行研究,并对本产品的灭菌稳定性进行了考察。结果表明本产品灭菌后较稳定,均匀细腻,其弹性模量、动力粘度和溶胀度均较好,具有很好的临床应用前景。     

交联透明质酸凝胶膜的制备及其生物相容性的研究

制备交联透明质酸凝胶膜并评价其生物相容性.本研究采用己二酸二酰肼作为交联剂制备交联透明质酸凝胶膜,并采用GB/T16886医疗器械生物学评价标准规定的方法,对凝胶膜进行体外溶血试验、细胞毒性试验、急性毒性试验、眼刺激试验、皮内反应试验、致敏试验以及鼠伤寒沙门氏菌回复突变试验、哺乳动物培养细胞染色体畸变试验和小鼠骨髓嗜多染红细胞微核试验等三项遗传毒性试验.结果表明交联透明质酸凝胶膜无溶血性、无眼刺激作用、无皮内刺激和致敏作用,未见急性毒性反应,细胞毒性0～1级;三项遗传毒性试验均为阴性.交联透明质酸凝胶膜具有良好的生物相容性,是一种理想的医用生物材料.     

交联透明质酸钠凝胶对近距离放射治疗中危及器官的隔离防护作用

背景：交联透明质酸钠凝胶具备良好的力学性能、生物相容性与降解性,可作为肿瘤放射治疗中的隔离防护材料,用于保护危及器官免受多余辐照剂量的损伤。目的：探究交联透明质酸钠凝胶在近距离放射治疗中减少危及器官受照剂量等方面的安全性及有效性。方法：取周龄相同、体质量相近的无特定病原体级昆明小鼠作为实验对象,共16只,采用随机数字表法分为实验组与对照组,每组8只。在实验组小鼠背部皮下植入¹²⁵I放射性粒子,随后环绕放射性粒子周边注射交联透明质酸钠凝胶,在对照组小鼠背部皮下仅植入¹²⁵I放射性粒子。注射完成后,采用螺旋CT扫描测量放射性粒子与表皮的距离,采用辐射剂量仪检测体表辐射剂量;注射后10周内,观察小鼠生长状态及存活率、皮肤放射损伤情况及凝胶存留量。结果与结论：(1)螺旋CT扫描显示植入的凝胶相对集中,并且使放射性粒子与表皮之间产生有效的间隔距离。实验组小鼠体表辐射剂量明显低于对照组(P <0.01)。(2)在实验观察期内,两组小鼠均存活,对照组小鼠在实验观察后期出现明显烦躁等不稳定表现,部分实验组小鼠出现类似行为;两组小鼠日摄食量无明显变化,体...     

透明质酸与京尼平的交联研究

对透明质酸与京尼平的交联反应进行初步的探索。透明质酸溶液中加入京尼平进行反应,采用UV 法和粘度法测定交联程度。考察反应时间、京尼平的量、透明质酸的浓度等因素对交联反应的影响。透明质酸与京尼平反应在48 h 时吸光度达到最大值,粘度变化不大。反应时间、京尼平的量及透明质酸的浓度是影响交联的因素,其中反应时间是主要影响因素,为进一步研究透明质酸的交联提供依据。     

透明质酸和EDC的轻度交联研究

我们用水溶性的碳化二亚胺(EDC)作为交联剂对透明质酸(HA)进行轻度交联,得到溶于水的产物.通过控制交联剂的使用量和反应时间,不同分子量的HA,其轻度交联的条件也不一样.对HA和碳化二亚胺的轻度交联作了初步的研究.     

原子荧光光谱法测定注射用透明质酸钠凝胶中砷和汞

目的建立利用原子荧光光谱法检测注射用透明质酸钠凝胶中砷和汞含量的方法。方法首先采用微波消解仪使样品完全消解,将样品消解液定容后,利用原子荧光光谱仪分析样品检验液中砷和汞的含量。通过标准曲线、检出限、精密度和加标回收率证明该方法的有效性。结果此方法中砷和汞的浓度分别在1~50 ng/m L和0.1~10 ng/m L范围内与荧光强度成良好的线性关系,相关系数分别是0.9999%和0.9997%。砷和汞的检出限分别是0.0105 ng/m L和0.0032 ng/m L,精密度RSD均5%,平均加标回收率分别是95.2%和100.2%。此面部注射用透明质酸钠凝胶样品中砷含量低于检出限(0.49 ng/g),汞含量为7.22 ng/g。结论用于测定注射用透明质酸钠凝胶中砷和汞含量的微波消解-原子荧光光谱法具有良好的线性范围、高灵敏度和准确度、重复性好等优点。     

MAPH: from gels to microarrays

The development of accurate and sensitive methodologies to detect small chromosomal imbalances (<3 Mb) is extremely important in clinical diagnostics and research in human genetics. The technique of array-comparative genomic hybridization (CGH) using BAC and PAC clones is very sensitive methodology and is rapidly becoming the method of choice for high-resolution screening of genomic copy-number changes. An alternative methodology to CGH is the multiplex amplifiable probe hybridization (MAPH) methodology, a DNA based method that allows the accurate and reliable determination of changes in copy number in "known" or "unknown locations" in the human genome. MAPH uses probes of 100-500 bp in size, that can be specifically designed for any gene or locus in the genome and cover any gene exons, the subtelomeric or subcentromeric regions, any chromosomal segment, a whole chromosome or the total human genome. MAPH can provide extremely high resolution and enable the sensitive detection of loss or gain of genomic DNA sequences as small as 150 bp. Very recently we succeeded in the advancement of MAPH from gel and capillary analyses to microarrays. The array-MAPH methodology offers an alternative methodology to array-CGH and provides a new sensitive microarray-based method including several advantages for the detection of copy number changes in the human genome.     

Cross-linked double-stranded RNA from a defective vesicular stomatitis virus particle

A class of vesicular stomatitis defective interfering virus particles isolated in this laboratory contains mostly double-stranded RNA of approximately 0.7–0.9 × 10⁶ daltons molecular weight. This RNA “snaps-back” or reanneals independently of concentration after heat denaturation but remains denatured if first nicked with ribonuclease. The nicked denatured products are about half the size of the double-stranded RNA and approximately half of them anneal to infectious virion single-stranded RNA. It is proposed that the complementary strands of this double-stranded RNA are cross-linked to each other, probably covalently. The structure can be viewed best as a hairpin or a closed circle base-paired along most of its length.     

Convective Patterns in Solution‐Casted Films from Acylated Hyaluronan

The evaporation of thin solution layers is an important process taking place in fields such as distillation, coating, or thin film manufacturing. Under suitable conditions, evaporation can induce convective flow by creating gradients in surface tension (Bénard–Marangoni instability) or density. These phenomena have been studied by many authors, but detailed and illustrative visualizations of real experiments are surprisingly scarce compared to simulation results and drawn schemes. Therefore, detailed and representative visualizations of regular Bénard–Marangoni convective cell patterns are provided in solution‐casted films from acylated hyaluronan. The visualizations agree with predictions made in the literature, thus providing important experimental validation. Most importantly, structures resulting from both horizontal and vertical convective flow are clearly visible. In a subsequent parametric study, the effects of selected parameters on the size of the convective cells are elucidated. The results suggest that the cell size increases with increasing solution layer height and increasing polymer concentration, while no statistically significant effect is observed for the degree of hyaluronan substitution.     

Molecular Control of the Hyaluronan Biosynthesis

Hyaluronan (HA) is the only unsulfated glycosaminoglycan (GAG) composed of repeating units of D-glucuronic acid and N-acetylglucosamine. The amount and the molecular weight of HA are important factors that regulate the physiology and pathology in several mammalian tissues. In fact hydrated HA makes ECM an ideal environment in which cells can move and proliferate. HA interacting with several receptors at the cellular level plays a critical role in signal transduction responses. The control of the HA synthesis is therefore a critical aspect in ECM and cells biology, but so far the information about this question is scanty. The synthesis of HA is due to several enzymes activities which not only involves its synthetic enzymes on the membranes of the cells (HA synthases 1, 2, 3, isoforms) but also the cytoplasmatic enzymes producing the UDP-sugar precursors. The UDP-sugars availability in cytoplasm is a critical point for the GAG synthesis and it seems to affect particularly the HA production. Eventually, the activity control of the enzymes involved in HA metabolism is obtained throughout both enzyme amount and their postsynthetic covalent modification, as phosphorylation. In fact, it was recently reported that HA synthase 3 may be phosphorylated after specific stimuli, and an increasing body of evidence supports the idea that the synthetic pathway of HA may be carefully regulated in all steps.     

Permeability properties of gels and membranes derived from chitosan

A series of membranes was prepared by air-drying the thin layers of N-acyl- and N-arylidene-chitosan gels. Their flow rates of water and permeabilities of various compounds were examined. N-Acylchitosan membranes were stable in both dilute acid and alkali, but N-arylidene-chitosan membranes were unstable in dilute acid. N-Acetylchitosan membranes were stable in formic acid at room temperature for up to 7 hr. The flow rates of water through N-acetylchitosan membranes were 10.0--23.6 X 10(-3) ml/cm2min under a pressure of 3 kg/cm2, and were unchanged by the membrane thickness (12--60 micrometers). The increase of carbon numbers for N-acyl groups caused a slight decrease in the flow rates, and the flow rates were decreased by partial O-acetylation of N-acetylchitosan membranes. The flow rate of water through chitosan membranes (thickness 30--35 micrometers) was 7.1 X 10(-4) ml/cm2min, which was decreased by an increase in the membranes thickness. Low-molecular-weight compounds (MW less than 2900) passed through these membranes, but high molecular-weight compounds (MW greater than 13,000) did not pass through.     

Extraction and identification of electroimmunoprecipitated proteins from agarose gels

A method for the identification of protein antigens captured in electroimmunoprecipitates was developed. Different antigen–antibody precipitates were generated by agarose gel immunoelectrophoresis. The immunoprecipitates were excised and various methods for extracting and dissociating the precipitates were systematically studied by analyzing for protein components of the extracts using peptide mass fingerprinting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimal recovery of antigen was obtained by 24-h extraction at 37 °C using a minimal volume of 0.06 M Tris–HCl, 10% SDS (pH 7). This simple and robust method is useful for the characterization of antibody specificity. It can also be used to identify antigens generating unknown precipitates in crossed immunoelectrophoresis with polyspecific antisera, including human IgG–antigen complexes electroimmunoprecipitated by secondary antibodies. Thus, the method may prove useful as an additional technique in biomarker discovery.     

Rapid and simple isolation of DNA from agarose gels

Summary We present a simple method for the isolation of DNA from agarose gels that is economic, fast, and independent of electrical equipment. DNA fragments of up to 6 kb can be easily extracted within 5 min using a disposable plastic syringe and filter paper. Total extraction of DNA fragments between 10 and 20 kb in size is achieved by concentrating the DNA flushed from the gel in a DNA-binding column.     

透明质酸医用润滑剂的润滑性研究

对透明质酸的润滑性进行研究。用摩擦系数仪测定样品的摩擦系数。与目前临床常用的医用润滑剂相比,透明质酸的润滑性更好。由于透明质酸是人体中天然存在的物质,因此安全性高、生物相容性好,适用于多种临床用途,是一种应用前景广阔的良好医用润滑成分。