Gelatin-based hemostatic agents for medical and dental application at a glance: A narrative literature review

Uncontrolled bleeding is linked to higher treatment costs, risk of post-surgical infection and increased disease and death. Hemostatic agents are used to treat excessive bleeding. A good hemostatic agent controls bleeding effectively, reduces the need for blood transfusion, removes the need for systemic drugs to control bleeding, results in shorter surgery time, and reduces the cost and length of hospital stay of the patient. Gelatin-based hemostatic agents have been widely used in medical and dental procedures, owing to their biodegradability and biocompatibility, as well as availability and low cost of raw materials. In this narrative literature review, we discuss the background and different types of gelatin-based hemostatic agents in medical and dental procedures, the comparison of gelatin-based and non-gelatin-based hemostatic agents, and the usage and development of enhanced or novel gelatin-based hemostatic agents. Gelatin-based hemostatic agents are effective and important part of bleeding control, as evidenced by its wide application in medicine and dentistry. The development of novel combination gelatin-based hemostatic agents has much potential for effective control of excessive bleeding.     

Exploring the feasibility of the use of biopolymers as a carrier in the formulation of amorphous solid dispersions – Part I: Gelatin

Biopolymers have rarely been used so far as carriers in the formulation of amorphous solid dispersions (ASD) to overcome poor solubility of active pharmaceutical ingredients (APIs). In an attempt to enlarge our knowledge on this topic, gelatin, type 50PS was selected. A screening study was initiated in which twelve structurally different poorly soluble biopharmaceutical classification system (BCS) Class II drugs (carbamazepine, cinnarizine, diazepam, itraconazole, nifedipine, indomethacin, darunavir (ethanolate), ritonavir, fenofibrate, griseofulvin, ketoconazole and naproxen) were selected for evaluation. Solid dispersions of five different drug loadings of these twelve compounds were prepared by lyophilization and evaluated for their solid state properties by mDSC and XR(P)D, and in vitro dissolution performance. Even without any process optimization it was possible to form either fully amorphous or partially amorphous systems, depending on the API and API to carrier ratio. Hence in this respect, gelatin 50PS behaves as any other carrier. Dissolution of the API from the solid dispersions significantly exceeded that of their crystalline counterparts. This study shows the potential of gelatin as a carrier to formulate amorphous solid dispersions.     

羟丙基淀粉空心胶囊对螺内酯含量的影响

摘 要 目的： 考察羟丙基淀粉胶囊对螺内酯胶囊主药含量的影响。方法: 分别在强光（4 000 Lx±500 Lx）、高温（40℃）、高湿（相对湿度75%±5%）的条件下放置5 d和10 d,采用高效液相色谱法检查样品放置前后含量改变,同时观察外观、色泽等药物性状的变化。结果:经高温、高湿、光照试验后,测得标示含量值均在93.45%～100.37%之间,符合标准规定（93.0%～107.0%）。结论: 羟丙基淀粉空心胶囊与螺内酯相容性较好。     

Microencapsulation of O/W emulsions by formation of a protein-surfactant insoluble complex

Abstract

A method for obtaining microcapsules of oil droplets by the formation of an insoluble complex of protein-surfactant is described. The gelatin type A studied, which is positively charged at the pH range studied, may form insoluble and soluble complexes with sodium dodecyl sulphate (SDS), an anionic surfactant. The binding isotherms were studied and the specific molar ratios of SDS to gelatin, in which the insoluble complex is formed, was determined. These specific ratios also led to the formation of microcapsules, in which the wall encapsulating the oil droplets, is composed of the insoluble gelatin SDS complex.     

Evaluation of Arterial Impairment after Experimental Gelatin Sponge Embolization in a Rabbit Renal Model

ObjectiveArterial stenosis is a major obstacle for subsequent interventional procedures. We hypothesized that the stenosis is caused by gelatin sponge embolization and performed an experimental study in a rabbit renal model.ResultsGelatin sponge particles were mainly observed in the segmental and interlobar arteries. Transmural inflammation of the embolized arterial wall and mild thickening of the media were observed 1 week after embolization. Resorption of the gelatin sponge and organization of thrombus accompanied by foreign body reactions, were observed from 2 to 4 weeks after embolization. Microscopic images of the 3 weeks group showed vessel lumens filled mostly with organized thrombi, resulting in severe stenosis. Additionally, vessels showed a thickened intima that contained migrating smooth muscle cells and accompanying interruption of the internal elastic lamina. The migrating smooth muscle cells were distributed around the recanalized arterial lumen.ConclusionGelatin sponge embolization may induce arterial stenosis by causing organized thrombus and intimal hyperplasia, which consists of migrating smooth muscle cells and intimal collagen deposits.     

Induction of endometrial mesenchymal stem cells into tissue-forming cells suitable for fascial repair

Pelvic organ prolapse is a major hidden burden affecting almost one in four women. It is treated by reconstructive surgery, often augmented with synthetic mesh. To overcome the growing concerns of using current synthetic meshes coupled with the high risk of reoperation, a tissue engineering strategy has been developed, adopting a novel source of mesenchymal stem cells. These cells are derived from the highly regenerative endometrial lining of the uterus (eMSCs) and will be delivered in vivo using a new gelatin-coated polyamide scaffold. In this study, gelatin properties were optimized by altering the gelatin concentration and extent of crosslinking to produce the desired gelation and degradation rate in culture. Following cell seeding of uncoated polyamide (PA) and gelatin-coated meshes (PA + G), the growth rate of eMSCs on the PA + G scaffolds was more than that on the PA alone, without compromising cell shape. eMSCs cultured on the PA + G scaffold retained their phenotype, as demonstrated by W5C5/SUSD2 (eMSC-specific marker) immunocytochemistry. Additionally, eMSCs were induced to differentiate into smooth muscle cells (SMC), as shown by immunofluorescence for smooth muscle protein 22 and smooth muscle myosin heavy chain. eMSCs also differentiated into fibroblast-like cells when treated with connective tissue growth factor with enhanced detection of Tenascin-C and collagen type I as well as new tissue formation, as seen by Masson’s trichrome. In summary, it was demonstrated that the PA + G scaffold is an appropriate platform for eMSC delivery, proliferation and differentiation into SMC and fibroblasts, with good biocompatibility and the capacity to regenerate neo-tissue.     

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。     

肠球菌部分致病基因和表型的检测

目的 调查临床分离的肠球菌6种致病基因和2种表型的分布。方法 应用聚合酶链反应和斑点杂交技术检测临床分离的145株肠球菌的6种致病基因，用7％兔血平板和3vA，明胶平板检测B溶血和明胶溶解表型。结果 粪肠球菌和屎肠球菌6种致病基因的检出率分别为gelE 72．9％、30．6％；efaA 79．2％、36．7％；cylA 54、2％、34．7％；esp 34、4％、36．7％；agg 18．8％、0；ace28．1％、0。粪肠球菌和屎肠球菌β溶血分别为45．8％、20．4％；明胶溶解分别为35、4％、16．3％。结论 粪肠球菌6种致病基因和2种表型的检出率高于屎肠球菌；尿标本比痰标本肠球菌致病基因的检出率高；gelE、efaA和cylA在粪肠球菌中的检出率高于其他致病基因。     

改良固定底物膜法对精子顶体透明质酸酶检测的研究

目的研制一种检测人精子透明质酸酶的改良底物膜法，以提高临床对男性不育的诊断水平。方法根据精子顶体透明质酸酶能溶解卵丘基质透明质酸的生化特性，通过改良透明质酸钠-明胶底物膜法，后进行孵育及染色来显示透明质酸酶的活性。本研究检测了70例人精子透明质酸酶活性，并结合临床精液常规检查结果选择和分组标本（生育组26例，不育A组13例，不育B组31例），对生育组与各不育组之间的平均酶活性进行统计学分析。结果在普通光镜下即可观察到在阳性反应区以深紫蓝色底膜为背景的清晰明亮的消化晕环，晕环数量及直径的大小与透明质酸酶活性成正比。生育组透明质酸酶平均阳性率为70．84％，酶活性亮区平均直径为78．17μm；不育A组酶平均阳性率为60．02％，酶活性亮区平均直径为76．92μm；不育B组酶平均阳性率为29．11％，酶活性亮区平均直径为8．22μm；经t检验，生育组酶活性两项指标均高于不育B组，差异有统计学意义（P〈0．01）。结论本研究检测方法简便、可靠，并可连续观察单个精子顶体透明质酸酶活性反应，很适合作为临床评价精子功能的有效指标，并提高对男性不育的诊断水平。