藻酸盐敷料治疗褥疮的疗效观察及护理

目的:观察藻酸盐敷料治疗褥疮的效果。方法:10例溃疡期褥疮患者采用常规清洗消毒方法加用藻酸盐敷料和标准型溃疡贴进行局部换药,观察溃疡情况。结果:用藻酸盐敷料加标准型溃疡贴治疗溃疡期褥疮,溃疡愈合时间短,换药时疼痛减轻。结论:藻酸盐敷料治疗褥疮有效,溃疡愈合时间缩短。     

藻酸钙伤口敷料加生肌散对肛瘘术后创面愈合作用

目的观察藻酸钙伤口敷料加生肌散对促进肛瘘术后创面的愈合作用。方法将100例肛瘘术后患者随机分为治疗组(60例)和对照组(40例),早期分别给予藻酸钙伤口敷料加生肌散和传统中药于肛瘘术后创面换药,后期常规换药至痊愈。观察两组创面愈合天数、创面渗液等疗效。结果治疗组在减少创面渗液﹑渗血﹑祛腐生新﹑减少疼痛及缩短愈合天数等方面的疗效明显优于对照组(P<0.01)。结论藻酸钙伤口敷料加生肌散对肛瘘术后创面的修复具有促进作用。     

Preparation of various solid-lipid beads for drug delivery of enrofloxacin

Solid-lipid beads were prepared to retard the release rate of enrofloxacin and to mask its bitter taste using carrageenan or sodium alginate as a shell material and either cacao butter or Witepsol W-35 as a solid lipid core. Sodium alginate was a better shell material than carrageenan and the highest loading efficiency was obtained using 2% sodium alginate. The alginate beads had a spherical morphology and a sturdy shell structure. The enrofloxacin release rate at room temperature was greatly reduced. Solid-lipid beads have the potential to mask the bitter taste of enrofloxacin and extend its release rate.     

In vitro and in vivo characterization of scleral implant of indomethacin: role of plasticizer and cross-linking time

Film-type scleral implants of indomethacin using sodium alginate and PEG 400 and 600 (3, 5, 8, and 10% w/w w.r.t. sodium alginate) as plasticizers were fabricated by solvent casting. The prepared implants were cross-linked by treatment with calcium chloride 10, 20, and 30% w/v solution, for periods between 1 to 24 hr. Uniformity of thickness, weight, and drug content and surface pH of the implants were evaluated. The influence of plasticizer type/concentration and crosslinking time/concentration of calcium chloride on indomethacin release was studied on a static dissolution setup developed by us. Selected batches of the implants were subjected to pharmacodynamic studies, after scleral placement, in uveitis-induced (intravitreal injection of bovine serum albumin 50 μg/ml) rabbit eyes. The release of indomethacin from the implants was influenced by the concentration and nature of plasticizers used. Chemical cross-linking with calcium chloride was successful in retarding the drug release. The pharmacodynamic studies showed a marked improvement in the various clinical parameters (congestion, keratitis, flare, clot, aqueous cells, and synechias) in the implanted eye when compared with the control eye in the rabbits. The implants survived for 2 weeks in vivo.     

Modulation of tnf-α-induced icam-1 expression,no and h<Subscript>2</Subscript>0<Subscript>2</Subscript> production by alginate,allicin and ascorbic acid in human endothelial cells

Plant nutrients are believed to provide protection against various diseases including inflammation. Since interactions of the cell adhesion molecules are known to play important roles in mediating inflammation, inhibiting adhesion protein upregulation is a possible therapeutic target. In this study, the interacellular adhesion molecule-1 (ICAM-1) was induced in human umbilical endothelial cells (HUVECs) after stimulation with TNF-alpha. In addition, alginate, ascorbic acid and allicin were demonstrated to inhibit the TNF-alpha induced expression of ICAM-1 on the HUVECs in a dose-dependent manner. These compounds also inhibited the production of NO and H2O2 induced by TNF-alpha, which suggests that the inhibition of ICAM-1 expression by the three compounds may be due to the modulated production of the reactive oxygen/nitrogen components. Overall, these results indicate that these dietary components have a therapeutic potential in the treatment of various inflammatory disorders associated with an increase in endothelial leukocyte adhesion molecules.     

Alginate-based pellets prepared by extrusion/spheronization: Effect of the amount and type of sodium alginate and calcium salts

Pellets containing microcrystalline cellulose (MCC), a model drug (theophylline) and a range of levels of sodium alginate (i.e., 10–50% w/w) were prepared by extrusion/spheronization. Two types of sodium alginate were evaluated with and without the addition of either calcium acetate or calcium carbonate (0, 0.3, 3 and 10% w/w). The effects of amount and type of sodium alginate and calcium salts on pellet properties, e.g., size, shape, morphology and drug release behavior, were investigated. Most pellet formulations resulted in pellets of a sufficient quality with respect to size, size distribution and shape. The results showed that the amounts of sodium alginate and calcium salts influenced the size and shape of the obtained pellets. However, different types of sodium alginate and calcium salt responded to modifications to a different extent. A cavity was observed in the pellet structure, as seen in the scanning electron micrographs, resulting from the forces involved in the spheronization process. Most of pellet formulations released about 75–85% drug within 60 min. Incorporation of calcium salts in the pellet formulations altered the drug release, depending on the solubility of the calcium salts used. The drug release data showed a good fit into both Higuchi and Korsmeyer–Peppas equations.     

凝胶材料制备方法及其反应动力学的研究进展

部分水凝胶材料具有良好的生物相容性、低细胞毒性和生物可降解性,广泛应用于组织工程和生物医药等领域,其中采用天然高分子明胶、壳聚糖和海藻酸钠制备复合凝胶材料,负载骨髓间充质干细胞用于修复和治疗骨缺损成为近年来的研究热点之一。因为水凝胶材料抗张强度低和化学稳定性差,所以研究凝胶反应机理和凝胶反应动力学对提高水凝胶的性能具有重要意义。本文总结了明胶、壳聚糖和海藻酸钠凝胶材料的制备方法和凝胶反应机理,比较了不同凝胶反应动力学研究方法,介绍凝胶复合材料在骨修复中的应用,为天然高分子凝胶材料的分子设计和临床应用提供思路。     

海藻酸盐支架-骨髓间充质干细胞复合物在急性肝衰竭大鼠体内的应用

目的: 探讨海藻酸盐支架-骨髓间充质干细胞(BMSCs)复合物在急性肝衰竭大鼠体内应用的可能性,为人工肝组织的体内应用提供基础。方法: BMSCs用氯甲基苯甲酰氨荧光染料(CM-DiI)标记后种植于海藻酸盐支架形成支架细胞复合物。动物分实验组和对照组,构建70%肝切除大鼠模型,实验组大鼠给予支架细胞复合物平铺于肝脏创面上,对照组给予单纯支架。4周后取出支架细胞复合物行荧光显微镜追踪观察;切片行白蛋白及糖原染色追踪支架上细胞的分化;同时比较两组大鼠生存率及肝功能变化情况。结果: CM-DiI能很好地标记细胞。体内应用后BMSCs能够在海藻酸盐支架上分泌白蛋白,合成糖原。实验组大鼠的生存率及肝功能改善情况优于对照组。结论: 海藻酸盐支架-BMSCs复合物在急性肝衰竭大鼠体内能够起到部分肝功能支持的作用。     

Magnetic alginate microspheres: system for the position controlled delivery of nerve growth factor

The use of polymeric carriers containing dispersed magnetic nanocrystalline particles for targeted delivery of drugs in clinical practice has attracted the interest of the scientific community. In this paper a system comprised of alginate microparticles with a core of magnetite and carrying nerve growth factor (NGF) is described. The magnetic properties of these microspheres, typical of superparamagnetic materials, allow precise and controlled delivery to the intended tissue environment. Experiments carried out on PC12 cells with magnetic alginate microspheres loaded with NGF have confirmed the induction of cell differentiation which is strongly dependent on the distance from the microsphere cluster. In addition, finite element modelling (FEM) of the release profile from the microspheres in culture, indicated the possibility of creating defined and predictable NGF gradients from the loaded microspheres. These observations on the carriage and release of growth factors by the proposed microparticles open new therapeutic options for both neuronal regeneration and of the development of effective neuronal interfaces.     

去甲斑蝥素肝动脉栓塞缓释微球的制备及其体外释放性评价

目的:制备去甲斑蝥素肝动脉栓塞缓释微球(NCTD-MS),并考察其体外释放特性。方法:以NCTD为主药,海藻酸钠ALG)/壳聚糖(CS)为复合载体,采用内部凝胶化法制备NCTD-MS;选取ALG浓度、凝胶化反应剂冰醋酸的用量、药物-载体重量比(简称药载比)为因素,以粒径偏差、载药量及包封率为指标进行正交设计优化最佳处方并进行验证;动态透析法考察微球在不同介质(磷酸盐缓冲液和生理盐水)中的体外释放特性,并与NCTD原料药的释放性进行比较。结果:最佳处方为ALG浓度2.0%、冰醋酸1.0mL、药-载重量比0.8∶1,以该处方制备的微球平均粒径为(309.75±2.19)μm、载药量为(12.65±0.87)%、包封率为(68.66±0.38)%;NCTD-MS在2种介质中24h释放可达80%,释放行为均遵循Weibull方程,而NCTD原料药在3h内即释放完毕。结论:NCTD-MS制备工艺简单,缓释效果明显。