Covalently immobilized gelatin gradients within three-dimensional porous scaffolds

A stable gelatin gradient providing continuous increment of signaling for cell adhesion and proliferation was fabricated within 3D poly（L-lactic acid） （PLLA） scaffolds. The porous PLLA scaffold fabricated by NaCI particle leaching was vertically fixed on a glass vial. 1,6-Hexanediamine/propanol solution was continuously injected into the vial by a micropump to aminolyze the PLLA scaffold. As a result of reaction time difference, the introduced -NH2 groups increased continuously along with the longitude of the PLLA scaffold in the z-direction. After covalent immobilization of gelatin by glutaraldehyde coupling, the gelatin gradient scaffold was thus obtained. In vitro chondrocyte culture showed that the cells had higher viability and more extending morphology in the gelatin gradient scaffold than that in the uniform gelatin control.     

Preparation and mineralization of PLGA/Gt electrospun fiber mats

Poly(lactic-co-glycolic acid)(PLGA)/gelatin(Gt) ultrafine composite fibers were fabricated via electro-spinning.The effect of gelatin on the morphology and tensile property of the electrospun fiber mats was investigated.Mineralization was carried out in 10×simulated body fluid(10SBF).The deposited calcium phosphate(CaP) was identified by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR).Results indicated that the av...     

铈钨杂多酸明胶薄膜修饰玻碳电极的制备和电化学行为

详细描述了铈钨杂多酸 K8[Ce W10 O3 6]· 30 H2 O(用 Ce W10 表示 )明胶膜修饰玻碳 (GC)电极的制备和 Ce W10 的电化学性质 .讨论了支持电解质的酸度对 Ce W10 的影响 ,以及 Ce W10 对氯酸根(Cl O-3 )和溴酸根 (Br O-3 )的电催化作用 .     

壳聚糖膨润土的制备工艺及表征

为了制备一种亲水性有机膨润土,以壳聚糖为改性剂.先把钠基膨润土高度分散到水中,然后慢慢加入到壳聚糖溶液中进行离子交换反应得到壳聚糖膨润土.以壳聚糖膨润土的有机化程度为考察目标,通过单因素实验考察了制备工艺条件的影响,并使用XRD、DSC对产物进行了结构表征.结果表明,4.0 g钠基膨润土在反应温度为60℃下与浓度为0.04 g·mL-1的200 mL壳聚糖溶液反应时间24 h,得到有机含量达到27.6%的壳聚糖膨润土.XRD表明,壳聚糖膨润土仍保留蒙脱石结构,其层间距为1.7nm;DSC表明壳聚糖膨润土中壳聚糖基团热稳定性明显高于壳聚糖.将该材料添加入明胶中,明胶的抗压强度提高可提高34%.壳聚糖膨润土的开发对膨润土和甲壳素资源的开发具有重要的意义.     

模板法制备明胶多孔微球

以单分散聚苯乙烯(PS)微粒为致孔剂,采用模板法制备了一种新型的明胶多孔微球,并用扫描电子显微镜(SEM)对其进行了表征.结果表明,通过调节PS微粒的用量和粒径大小可以控制微球和孔径的大小,且微球表面有均匀的孔结构.     

明胶与Cu2+的结合平衡研究

利用分光光度法,研究了不同酸度下,Cu2+与明胶结合反应的结合数、结合位置数和摩尔吸光系数.显微红外光谱的测定结果表明,Cu2+与明胶分子中的酰胺键发生了作用.推导出由吸光度计算结合平衡常数的理论公式,并计算出结合平衡常数.结果表明,随pH值增大,结合数增多; 结合平衡常数增大.     

明胶诱导矿化合成不同形貌碳酸钙的研究

采用仿生矿化法,以明胶为模板剂,矿化合成不同形貌碳酸钙。采用FESEM、XRD和FT-IR技术对产物的组成和结构进行了表征,并通过明胶浓度、钙离子浓度和晶化时间的变化考察了明胶在碳酸钙矿化过程中的作用机制。结果表明:明胶和钙离子的物质的量比对产物结构有较大影响,随着物质的量比的逐渐减小,产物由致密球体结构转变为双螺形、类球形以及疏松球体结构;另外,明胶分子还可稳定球霰石晶相的存在,但最终由于球霰石向方解石晶相的转化导致了凹孔结构碳酸钙的出现。     

提高重铬酸盐明胶全息图衍射效率的一种新方法

本文根据重铬酸盐明胶的性质,提出了一种处理重铬酸盐明胶板的新方法——两步法,得到了较好的实验结果。     

A gelatin sponge model for studying tumor growth: quantitation of tumor cells and leukocytes in the CHO tumor

Summary A gelatin sponge model system for tumor cell inoculation and retrieval of tumor-associated leukocytes is described. Gelatin sponges pre-implanted in nude mice harboring tumorigenic Chinese hamster ovary cells (line CHO) were examined at 2 and 11 days after injection of tumor cells for tumor cell content and leukocyte accumulation after digesting the sponge matrix in collagenase solution.The data indicate a progressive influx of host cells consisting primarily of macrophages, neutrophils and lymphocytes. The total number of viable tumor cells as well as the fraction of surviving tumor cells with clonogenic potential also increased with tumor age. Blank sponges not harboring tumor cells elicited an inflammatory response in the animals which did not change appreciably with length of sponge residence. However, when the sponges were harboring tumor cells, the accumulation of host leukocytes far exceeded that which occurred in blank sponges. This observation suggests a host response directed toward the tumor which is absent in animals bearing blank sponges. Apart from providing anchorage for injected cells, the gelatin sponge, by virtue of its digestibility in collagenase, makes possible the easy retrieval and precise quantitation of tumor-associated host cells.Supported by the United States Department of Energy and National Institutes of Health Grant P41-RR01315.     

京尼平对壳聚糖及明胶的交联反应

壳聚糖和明胶均具有良好的生物相容性,但作为医用植入材料其力学性能往往不能达到要求.交联是改善其力学性能的常用方法,但传统化学合成交联剂均具有相对较高的细胞毒性.选用天然化合物京尼平为生物交联剂,借助紫外光谱分析方法,对京尼平与壳聚糖的交联反应过程进行跟踪研究,建立了该交联反应机理及动力学的初步模型.对壳聚糖-京尼平和壳聚糖-明胶-京尼平复合体系的力学性能和溶胀性能进行了探讨,并研究了在溶菌酶的存在下壳聚糖-京尼平复合体系的降解行为.结果表明,壳聚糖-明胶-京尼平复合体系的机械性能与京尼平的加入量有明显的关系.