皮胶原及其在组织工程中的应用

本文概括地阐明了胶原的生物合成及其主要结构特征，对胶原的若干性质，诸如理化性质、物理一机械性能以及生物医用性能等进行了讨论。特别是对皮胶原在组织工程中的应用进行了详细的介绍，最后指出皮胶原在组织工程中具有广阔的应用前景。     

Analysis of tannins in seeds and skins of Shiraz grapes throughout berry development

The flavan-3-ol and proanthocyanidin composition of both seeds and skin of Vitis vinifera L. cv. Shiraz grapes was determined by reversed-phase HPLC after acetone extraction and acid-catalysis in the presence of excess phloroglucinol. Samples were taken at weekly intervals from fruit-set until commercial harvest. The main period of proanthocyanidin accumulation in grape seeds occurred immediately after fruit-set with maximum levels observed around veraison. Over two seasons there was variation in both the timing and content of proanthocyanidins in seeds. In skin, proanthocyanidin accumulation occurred from fruit set until 1–2 weeks after veraison. Proanthocyanidin subunit composition was different in seeds and skin and changed during berry development but the mean degree of polymerisation of the tannin polymers in skins was higher than in the seeds at all stages of berry development. Proanthocyanidin levels in both seeds and skin decreased between veraison and harvest. Additional proanthocyanidin subunits were released when the residues remaining after acetone extraction were subjected to direct acid-catalysis in the presence of phloroglucinol. In the seeds, these accounted for much of the post-veraison decrease, but not in grape skin. At harvest, 75% of extractable berry proanthocyanidin was in the seeds. Accumulation of proanthocyanidins in the seeds appears to be independent of that in the skins, but in both tissues synthesis occurs early in berry development and maximum levels are reached around veraison.     

月桂酸衍生物的合成与抑菌性的比较研究

本文进行了月桂酸衍生物(月桂酸单甘酯GML、月桂酸双甘酯和三甘酯GDL+GTL、聚甘油月桂酸单甘酯PGML)合成的研究,并比较了其抑菌活性和皮肤致敏性,以获得应用性能更佳的月桂酸产品。采用固体酸性盐催化的酯化反应合成月桂酸衍生物,优化的反应条件为:催化剂NaHSO4用量为月桂酸重的0.3%,底物摩尔比为1:2,温度200℃、真空条件下反应5h;反应产物采用分子蒸馏提纯,得到的月桂酸单甘酯和聚甘油月桂酸单甘酯纯度较高。采用平板菌落计数法测定月桂酸衍生物的最低抑菌浓度,结果表明:月桂酸、GML和PGML对革兰氏阳性菌和阴性菌均有较好的抑菌活性,但在相同条件下月桂酸和GML的抑菌效果要优于PGML,GDL+GTL则无抑菌活性。通过皮肤致敏性测试,证实月桂酸衍生物均不会导致人体皮肤过敏。     

Portable erythema meter and its application to use in human skin

In this study a compact, hand-held, solid state erythema meter using light emitting diodes is described. This device has been constructed and used to compare with visual assessments of ultraviolet radiation in human subjects. A statistically significant correlation was obtained between erythema index and visual assessment in 24 ultraviolet irradiated subjects. Furthermore, the effects of three aftersun treatments have also been assessed objectively using the meter and subjectively using visual assessments. The ultraviolet-irradiated areas were less red following treatment than the irradiated and untreated areas. The results obtained by the meter were similar to and statistically significant with those obtained by visual assessment.
It is concluded that widespread use of an erythema meter such as that described would greatly improve all cutaneous erythema assessments.     

新疆木纳格葡萄皮中花青素微波提取工艺及其稳定性研究

花青素是一种存在于自然界的水溶性多酚类化合物,普遍分布于植物花瓣、果实、茎和叶等器官中,也是天然色素的一种,被广泛应用在食品、保健品和化妆品行业.因此,文章以葡萄皮渣为研究对象,通过单因素试验和正交试验,确定了新疆木纳格葡萄皮中花青素微波提取的最佳工艺为:提取溶剂为15％酸性乙醇,微波功率为800 W,料液比1:20(g/mL),提取时间为90 s,浸提温度为65℃,提取次数为2次.花青素稳定性研究表明,光照条件下花青素稳定性较差;高温对花青素有降解作用,60℃以下稳定性良好;pH值为5时花青素稳定性好;金属离子Cu2+和Al3+对花青素的稳定性影响显著;苯甲酸对花青素稳定性影响显著.     

电感耦合等离子体质谱法同时测定马鹿皮中9种元素

目的建立微波消解-电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)法同时测定马鹿皮中钠、锰、镁、钾、钙、铁、硒、铜和锌9种元素的含量的方法。方法样品经硝酸-过氧化氢微波消解后,通过在线加入内标溶液校正,以72Ge为内标,采用ICP-MS测定马鹿皮中钠、锰、镁、钾、钙、铁、硒、铜和锌9种元素的含量。结果 9种元素线性良好,相关系数为0.9995~1.0000;钠、锰、镁、钾、钙、铁、硒、铜和锌的检出限分别为4、0.007、0.2、1、1、0.3、0.004、0.009、0.05 mg/kg;9种元素的回收率在86%~116%之间;相对标准偏差(relative standard deviation,RSD)≤7.2%(n=6)。结论该方法灵敏度高、稳定性好,可以满足马鹿皮中钠、锰、镁、钾、钙、铁、硒、铜和锌的测定。     

响应面法优化鳕鱼皮胶原蛋白肽螯合铁工艺

采用响应面法优化鳕鱼皮胶原蛋白肽与氯化亚铁进行螯合反应的条件,制备小分子肽螯合铁产品。以pH值、小分子肽与FeCl2的质量比和小分子肽液质量分数3因素的5水平进行二次正交旋转组合试验,建立螯合物得率的二次回归方程。结果表明：最佳螯合工艺条件为胶原蛋白肽与氯化亚铁的质量比4:1、小分子肽液质量分数3.5%、pH7.0。在此条件下,螯合物得率为37.31%,与模型的预测值37.46%接近。红外光谱检测结果显示,亚铁离子与小分子肽中的NH2+和COO－有螯合,是一种新型螯合物。     

生物质科学与工程及其发展前景

以可持续发展的思想为指导，从生物多样性出发，广义地定义了生物质、生物质科学与工程，初步探讨了生物质、生物多样性与生态环境之间的关系，阐明了建立生物质科学与工程学科的重要意义，展望了该学科的发展前景。     

基于不同提取方式的鱼皮胶原蛋白对重组鱼肉品质的影响

为了提高淡水鱼糜制品的品质,本研究以草鱼为原料,用盐法、酸法和碱法提取鮰鱼皮中的胶原蛋白,探究其对重组鱼肉品质的影响及作用机制。通过对重组鱼肉的凝胶强度、TPA质地特性(硬度和咀嚼性)、析水率以及白度值的分析变化,综合评判胶原蛋白对重组鱼肉品质的影响,并通过化合作用力、蛋白质溶解率和TCA可溶肽含量,以及石蜡组织切片和SDS-PAGE探究了鱼皮胶原蛋白在重组鱼肉中的作用机制。结果发现:胶原蛋白显著提升了重组鱼肉的品质特性,提升效果为碱法酸法盐法;而其作用机制也有差异:碱溶性胶原蛋白与鱼糜凝胶的过程中不仅形成二硫键,且活化了內源转谷氨酰胺酶(TG)生成较多非二硫共价键,增强了凝胶网络结构;酸溶性胶原蛋白在凝胶时形成了二硫键,增强凝胶作用力;而盐溶性胶原蛋白与鱼肉蛋白形成的高分子物质增强了凝胶网络结构。     

Lactobionic acid as antioxidant and moisturizing active in alkyl polyglucoside-based topical emulsions: the colloidal structure, stability and efficacy evaluation

Cosmeceutical antioxidants may protect the skin against oxidative injury, involved in the pathogenesis of many skin disorders. However, an unsuitable topical delivery system with compromising safety profile can affect the efficacy of an antioxidant active. This study investigated the antioxidant potential of lactobionic acid (LA), a newer cosmeceutical active, per se (in solution) and incorporated into natural alkyl polyglucoside (APG) emulsifier-based system using 1,1-diphenyl-2-picrylhydrazyl free radical scavenging and lipid peroxidation inhibition assays. The α-tocopherol was used as a reference compound. The physical stability (using rheology, polarization microscopy, pH and conductivity measurements) of an Alkyl glucoside-based emulsion was evaluated with and without the active (LA); colloidal structure was assessed using polarization and transmission electron microscopy, rheology, thermal and texture analysis. Additionally, the safety profile and moisturizing potential were investigated using the methods of skin bioengineering. Good physical stability and applicative characteristics were obtained although LA strongly influenced the colloidal structure of the vehicle. LA per se and in APG-based emulsion showed satisfying antioxidant activity that promotes it as mild multifunctional cosmeceutical efficient in the treatment and prevention of the photoaged skin. Employed assays were shown as suitable for the antioxidant activity evaluation of LA in APG-based emulsions, but not for α-tocopherol in the same vehicle.