hVEGF基因工程生物膜对全层皮肤缺损创面愈合的影响

目的探讨含人血管内皮细胞生长因子(hVEGF)重组质粒的成纤维细胞种植的基因工程生物膜对大鼠全层皮肤缺损创面愈合的作用。方法在SD大鼠背部皮肤制作深达皮肤全层的正方形创面,实验组大鼠创面上覆含hVEGF重组质粒的成纤维细胞种植的基因工程生物膜;对照组分别在大鼠创面上覆整合空质粒的成纤维细胞的生物膜、空白生物膜和仅覆切口膜。采用形态学和免疫组化方法,观察术后3、7、14、29 d实验组和对照组大鼠创面肉芽组织生长及创面愈合情况。结果在各时相实验组中新生的毛细血管数以及血管内皮细胞生长因子(VEGF)表达均显著高于对照组(P<0.01),且VEGF表达与新生毛细血管数正相关。结论将含hVEGF重组质粒的成纤维细胞种植的基因工程生物膜覆盖于大鼠全层皮肤缺损创面,能使创面成纤维细胞持续、有效地表达VEGF,强有力地促进肉芽组织增生,有利于创面愈合。     

Effectiveness of pretreatment with phosphoric acid,sodium hypochlorite and sulfinic acid sodium salt on root canal dentin resin bonding

PurposeThe purpose of this study was to evaluate the effect of pretreatment using phosphoric acid, sodium hypochlorite and sulfinic acid sodium salt on the bonding of one-step self-etching adhesives to root canal dentin.MethodsThirty-six single-rooted sound human premolars were randomly assigned into three groups before applying the one-step self-etching adhesive. These comprised a control group with no pretreatment, an NC group that received phosphoric acid and subsequent sodium hypochlorite gel pretreatments, and an NC + AC group that received an additional treatment with sulfinic acid sodium salt following the same pretreatment applied to the NC group. Microtensile bond strength measurements, bonding interface observations by scanning electron microscopy (SEM), elemental analyses by X-ray photoelectron spectroscopy (XPS) and degree of polymerization (DOP) analyses by Raman spectroscopy were subsequently performed.ResultsThe bond strength was significantly higher in the NC + AC group than in the other two groups (Control: P = 000.1 and NC: P = 0.004). SEM observations showed that resin tags were present in the dentinal tubules in the NC and NC + AC groups. Compared to the control group, the adhesive resin layer had a lower DOP in the NC group, while the DOP for the NC + AC group was higher than that of the NC specimens.ConclusionsBonding to root canal dentin was improved by applying sulfinic acid sodium salt in addition to treatment with phosphoric acid followed by sodium hypochlorite. The DOP of the adhesive resin was reduced by sodium hypochlorite and subsequently restored by applying sulfinic acid sodium salt.     

Increased collagen degradation by experimentally-induced granulation tissue inoculated with bacteria

Abstract Periodontitis is characterized by asymptomatic periodic collagen degradation, which is accompanied by the formation of granulation tissue induced by bacteria. The lesions sometimes contain micro-organisms and/or micro-abscesses that are of unknown significance. The aim of this study was to determine whether bacteria in a sterile granulation tissue could enhance its collagenolytic capacity. The formation of granulation tissue was induced by implanting a cellulose sponge in the subcutaneous tissue in the back of the rat. Bacteria were injected every other day into the sponge from day 8 to day 18. The cell-dependent degradation of a homologous ³H-collagen powder enveloped in the sponge was measured by the radioactivity of the urine excreted 8–18 days after the implantation. The injections increased the excretion of radioactivity by about 40% compared with the controls (n=8, p0.005), but caused no clinical signs of acute infection or inflammation. On day 18, 2 days after the last injection of bacteria, no bacteria or increased cell infiltration were observed in the granulation tissue. The appearance of the latter could not be distinguished from that of the control tissues injected with buffer alone. It seems reasonable to assume that the increased collagen degradation results from enhanced activity of phagocytes, which may also be related to an increased release of tissue-destructive proteases and free oxygen radicals into the extracellular space. In conclusion, brief recurrent episodes of bacteria in granulation tissue can increase its collagen degrading-capacity. The latter may be due to augmented cell activity in the tissue. This response seems to have some features comparable to the pathogenesis of episodic periodontitis, e.g., by mimicking the collagen degradation.     

挤出滚圆法制备药用微丸：Ⅰ.设备的工作原理及特点

概述了用挤出滚圆法制造球粒的特点和制造球形微丸的原理及方法。利用该方法开发的专利产品球形微丸造粒机能以工业规模制造各种规格的球粒。综述了用该机制造药用微丸的方法     

Basic studies on the application of an artificial esophagus using cultured epidermal cells

In making an artificial esophagus, the transplantation of the epithelialized granulation tube fabricated by organized synthetic material was studied mainly from the viewpoint of preventing anastomotic leakage and stricture formation. The possibility of epithelialization of the inner surface of a granulation tube using cultured epidermal cells was studied in rats and dogs. A stainless steel mesh tube coated with silicon served as the granulation tube. Epithelialization on the inner surface of a granulation tube was evaluated by seeding cultured epidermal cells. A skin sample was treated with dispase and trypsin to collect epidermal cells, which were cultured in a keratinocyte growth medium. Once confluence was achieved, the epidermal cell suspension was harvested using the following methods: trypsin treatment (n=15), mechanical separation with a cell scraper (n=6), and dispase treatment (n=9). The cultured epidermal cell suspension was then seeded into the lumen of the granulation tubes. The attachment of cultured epidermal cells was attained in 2 of 15 cases by trypsin treatment, and in 5 of 9 cases by dispase treatment. No attachment occurred using the cell scraper method. All attached epidermal cells exhibited a cobblestone appearance on the granulation tissue with a tendency toward stratification. These findings show that the inner surface of a steel mesh granulation tube was epithelialized by cultured epidermal cells.     

消炎去脂片不同工艺制备过程中指标成分含量变化研究

目的 考察消炎去脂片不同工艺制备过程中指标成分含量变化情况.方法 分别采用真空干燥、微波干燥对组方提取、浓缩制备的流浸膏进行干燥,制得干浸膏,再分别加辅料制备成颗粒,采用喷雾干燥制粒法将流浸膏直接喷雾干燥制粒,超高效液相色谱法(UPLC)检测消炎去脂片干浸膏、成品颗粒中黄芩苷和栀子苷的含量,考察真空干燥、微波干燥和喷雾干燥及制粒过程对指标成分含量变化的影响.结果 以组方中指标成分含量为指标,真空干燥含量均最低,喷雾干燥与微波干燥相近或互有高低.制粒、烘干过程对黄芩苷含量影响较大,而对栀子苷含量影响不大.结论 不同干燥方法及制粒、烘干工艺对中药制剂制备过程中指标成分含量均有影响,实际工艺研究中必须进行有效的筛选.     

制粒技术在药物掩味方面的研究进展

在常用的口服固体制剂中,口感不良会导致患者对药物的依从性差,进而使得该药物的市场竞争力降低。药物制剂的掩味问题一直是制剂学面临的重要问题之一,随着人们对药物口感的要求日渐提升,近几年掩盖药物不良口味的方法也逐渐增加。通过对掩盖药物不良口味的相关文献进行总结,常用的掩味技术有添加掩味剂、包合技术、微球/微囊技术、固体分散技术、离子交换技术等。然而,除以上掩味技术之外,在固体制剂的制造过程中,制粒技术也可以实现对药物不良口味的遮蔽,且制粒技术方法简单,能够很好地达到掩盖药物不良口味的效果,该文系统介绍了制粒技术在药物掩味方面的研究进展,以期为药物掩味技术的选择提供参考。随着人们对药物口感的需求逐渐提高,药物掩味技术越来越受到广大制剂工作者的重视,但目前仍然存在一些问题,如口感评价体系不完善、方法特异性较低等,这一系列的问题均有待于相关药学工作者进一步研究和解决。     

Combining formulation and process aspects for optimizing the high-shear wet granulation of common drugs

The purpose of this research was to determine the effects of some important drug properties (such as particle size distribution, hygroscopicity and solubility) and process variables on the granule growth behaviour and final drug distribution in high shear wet granulation. Results have been analyzed in the light of widely accepted theories and some recently developed approaches.A mixture composed of drug, some excipients and a dry binder was processed using a lab-scale high-shear mixer. Three common active pharmaceutical ingredients (paracetamol, caffeine and acetylsalicylic acid) were used within the initial formulation. Drug load was 50% (on weight basis).Influences of drug particle properties (e.g. particle size and shape, hygroscopicity) on the granule growth behaviour were evaluated. Particle size distribution (PSD) and granule morphology were monitored during the entire process through sieve analysis and scanning electron microscope (SEM) image analysis. Resistance of the wet mass to mixing was furthermore measured using the impeller torque monitoring technique. The observed differences in the granule growth behaviour as well as the discrepancies between the actual and the ideal drug content in the final granules have been interpreted in terms of dimensionless quantity (spray flux number, bed penetration time) and related to torque measurements. Analysis highlighted the role of liquid distribution on the process. It was demonstrated that where the liquid penetration time was higher (e.g. paracetamol-based formulations), the liquid distribution was poorer leading to retarded granule growth and selective agglomeration. On the other hand where penetration time was lower (e.g. acetylsalicylic acid-based formulations), the growth was much faster but uniformity content problem arose because of the onset of crushing and layering phenomena.     

Fabrication of three-dimensional nanofibrous gelatin scaffolds using one-step crosslink technique

Abstract

Electrospun nanofibers have been considered to be an ideal scaffold for tissue engineering, because of the extracellular-matrix-like structure and the well-controlled fabrication. Here, a new method was used to fabricate electrospun three-dimensional macroporous nanofibrous gelatin scaffolds in ethanol bath by one-step crosslink with glutaraldehyde. The mean diameter of the one-step crosslinked fibers was significantly smaller than that of the traditional two-step crosslinked fibers (p?<?0.05), and scaffolds prepared by one-step crosslink were fluffy and porous. No significant difference was found in the degradation rates for both fibers within 14 days. After immersion in PBS for 14 days, numerous two-step crosslinked fibers merged together. By contrast, the morphology and macroporous structure of one-step crosslinked fibers showed no evident change and were generally maintained. Approximate crosslinking degrees of the two-step and one-step crosslinked gelatin fibers were 40% and 54%, respectively (p?<?0.05). Results from fluorescence microscopy and hematoxylin-eosin staining showed that MC3T3-E1 subclone four cells were distributed more evenly and diversely in the one-step crosslinked fiber scaffolds. The one-step crosslinked fibers enhanced the proliferation and differentiation potential of MC3T3-E1 cells. Furthermore, one-step crosslinked fibers were beneficial in repairing defects in the skulls of rats. Thus, one-step crosslink by glutaraldehyde in ethanol bath is a cost-effective and simple method to fabricate three-dimensional macroporous nanofiberous scaffolds. This technique retains the morphology and structure of the gelatin fibers, and enhances the biological performance of scaffolds in vitro and in vivo.