藻酸钙敷料的促凝血机制

背景：藻酸钙敷料近年来被广泛应用于手术止血、外伤止血、鼻腔术后止血、穿刺部位止血等,但有关其止血机制的国内外研究较少。 目的：初步探讨藻酸钙敷料的促凝血机制。 方法：将人抗凝血分别滴加至藻酸钙敷料、纳吸棉与医用棉纱布上,室温静置2 min,扫描电镜下观察材料与血液的相互作用;在人红细胞悬液中分别加入藻酸钙敷料、纳吸棉与医用棉纱布,静置15 s,扫描电镜下观察材料与红细胞的相互作用;在人红细胞中分别加入10,5,2.5 g/L的藻酸钙敷料浸提液,观察作用30,60,120 min的红细胞沉降率;在人富血小板血浆中分别加入10,5,2.5 g/L的藻酸钙敷料浸提液,37 ℃孵育10 min,流式细胞仪检测CD62P阳性血小板百分率。 结果与结论：藻酸钙敷料与抗凝血接触后可见致密的纤维蛋白网形成,其中网罗大量血细胞;纳吸棉组与医用棉纱布组仅见少量红细胞及血小板黏附。藻酸钙敷料与红细胞相互作用后可见红细胞变形,有伪足样改变,纳吸棉组与医用棉纱布组红细胞形态无变化。藻酸钙敷料浸提液呈剂量与时间依赖性提高红细胞沉降率,组间两两比较差异有显著性意义(P < 0.01);藻酸钙敷料浸提液呈剂量依赖性提高CD62P阳性血小板百分率,组间两两比较差异有显著性意义(P < 0.01)。表明藻酸钙敷料可通过释放钙离子、引起红细胞聚集和变形、活化血小板等促进止凝血过程。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

贻贝粘蛋白创面修复敷料体外细胞毒性的检测方法

背景：在贻贝粘蛋白创面修复敷料的体外细胞毒性检测中,由于蛋白分子表面带正电荷,1∶9的浸提比会使细胞聚团而导致测定产生误差,影响测定结果。 目的：在已有标准的基础上,根据贻贝粘蛋白特殊的性质及使用状态,改进贻贝粘蛋白创面修复敷料的浸提比例或前处理方法。 方法：①浸提液法：将贻贝粘蛋白创面修复敷料与细胞培养液分别以1∶9、1∶131浸提比例制备浸提液,分别以贻贝粘蛋白创面修复敷料浸提液、天然乳胶浸提液、高密度聚乙烯浸提液及细胞培养液培养L929小鼠成纤维细胞。②直接接触法：分别以蒸馏水、贻贝粘蛋白创面修复敷料溶液、二甲基亚砜及细胞培养液培养L929小鼠成纤维细胞。 结果与结论：采用浸提比1∶9测定样品体外细胞毒性时,细胞产生聚团作用,不适用于样品毒性的检测;调整浸提比为1∶131后,絮凝作用和细胞聚团现象明显降低,提高了检测结果的可信度,显示样品无细胞毒性。直接接触法显示样品无细胞毒性。采用经调整过的浸提液法或直接接触法均可适用于贻贝粘蛋白创面修复敷料体外细胞毒性的检测。     

四甲基偶氮唑盐法评价牙体修复性纳米羟基磷灰石复合材料的体外细胞毒性

背景：越来越多的新型材料被纳入口腔领域应用的视野,对生物材料进行生物相容性评价是进入临床试验前的重点研究内容。 目的：通过体外细胞毒性实验评价自制牙体修复性纳米羟基磷灰石复合材料的生物相容性。 方法：根据ISO标准,采用四甲基偶氮唑盐比色法行体外细胞毒性实验,阴性对照组为DMEM培养液,阳性对照组为含有0.1%苯酚的DMEM培养液,实验组为受试材料的浸提液。测试人牙龈成纤维细胞在牙体修复性纳米羟基磷灰石复合材料浸提液中培养1,3,5 d的吸光度值,观察细胞形态变化,计算细胞相对增殖率,判断细胞毒性的级别。 结果与结论：实验组体外细胞毒性实验吸光度值均与阴性对照组差异无显著性意义(P > 0.05),与阳性对照组差异有显著性意义(P < 0.01),自制牙体修复性纳米羟基磷灰石复合材料体外细胞毒性级别为0~1级,初步认为其具有良好的生物相容性。     

铁铬钼软磁合金表面镀铬后的生物相容性

背景：研究表明,铁铬钼系列软磁合金具有理想的磁性能和机械加工性能,表面镀Cr⁶⁺处理可明显增强其在口腔环境中的耐腐蚀性,但其表面镀铬后的生物安全性仍需进一步检验。目的：评价铁铬钼软磁合金表面镀铬后的生物相容性。方法：取对数生长期L-929细胞悬液,以6×10⁷ L^-1的细胞浓度接种于96孔板中,分别加入纯钛浸提液、铁铬钼软磁合金原样浸提液、铁铬钼电镀Cr⁶⁺软磁合金浸提液与聚氯乙烯浸提液培养。培养5 d后,观察细胞形态和贴壁情况,采用CCK-8法检测细胞A值,并计算各组细胞相对增殖率,评价材料细胞毒性分级。结果与结论：纯钛浸提液组细胞形态正常,贴壁生长良好,表现为无细胞毒性;铁铬钼软磁合金原样浸提液组细胞形态和生长状态均良好,偶见个别细胞溶解,培养液内出现散在红褐色颗粒,表现为无或极轻微的细胞毒性;铁铬钼镀Cr⁶⁺软磁合金浸提液组细胞生长状态良好,表现为无或极轻微的细胞毒性;聚氯乙烯浸提液组超过70%细胞固缩或溶解呈空泡状,大量细胞碎片,超过50%细胞生长抑制,表现中度以上的细胞毒性。铁铬钼电镀Cr⁶⁺软磁合金浸提液的细胞毒性为0至1级。表明镀铬的铁铬钼软磁合金具有良好的生物相容性。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

新型医用无镍不锈钢的生物相容性评价

背景：BIOSSN4无镍不锈钢是一种奥氏体医用不锈钢材料,在中国药品生物制品检定所通过了标准的溶血实验、细胞毒性实验和致敏实验。 目的：评价新型医用BIOSSN4无镍不锈钢的体外细胞毒性及抗腐蚀性。 方法：将小鼠L929成纤维细胞悬液以1×108 L-1的浓度接种于96孔板,分5组培养,分别加入BIOSSN4无镍不锈钢浸提液、316L不锈钢浸提液、金合金浸提液、铅材料浸提液(阳性对照)及RPMI1640培养液(阴性对照)。培养1,2,3 d,观察细胞形态,采用MTT法检测各组吸光度值,计算细胞相对增殖率,评价毒性分级。在模拟口腔环境中,检测BIOSSN4无镍不锈钢、316L不锈钢及金合金的自腐蚀电位、自腐蚀电流密度及极化电阻。 结果与结论：培养3 d内,铅材料浸提液组细胞皱缩,细胞数量明显减少,细胞相对增殖率低于其余4组(P < 0.05);其余4组细胞形态良好,增殖旺盛,细胞相对增殖率均在75%以上。BIOSSN4无镍不锈钢浸提液、316L不锈钢浸提液与金合金浸提液的毒性均为1级,铅材料浸提液的毒性为2至3级,表明BIOSSN4无镍不锈钢具有良好的生物相容性。BIOSSN4无镍不锈钢的抗腐蚀性高于316L不锈钢,低于金合金。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

纳米含氟羟基磷灰石牙种植体的生物相容性

背景：有关纳米含氟羟基磷灰石牙种植体材料生物相容性的报道较少。 目的：检测纳米含氟羟基磷灰石牙种植体材料的体外生物相容性。 方法：采用溶胶凝胶技术分别制备羟基磷灰石与纳米含氟羟基磷灰石。①溶血性实验：在0.2 mL稀释兔抗凝血中分别加入0.01,0.15,0.2 g/L纳米含氟羟基磷灰石溶液、生理盐水及蒸馏水各10 mL,检测各组上清液吸光度值。②体外细胞毒性实验：分别以100%,50%纳米含氟羟基磷灰石浸提液、100%羟基磷灰石浸提液、苯酚溶液及RPMI1640培养液培养传至第2代的L929细胞,MTT法检测培养2,4,7 d的吸光度值。 结果与结论：体外溶血性实验显示,各浓度梯度纳米含氟羟基磷灰石的溶血率均在5%以内,符合医用材料的溶血要求。体外细胞毒性实验显示,随着培养时间的增加,100%,50%纳米含氟羟基磷灰石浸提液组细胞贴壁覆盖率增加,细胞密度增高,细胞为长梭形或多角形,细胞增殖及形态与RPMI1640培养液组、羟基磷灰石组无明显差别,细胞毒性为0级。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

明胶/白芨胶多孔材料的细胞相容性研究

目的以明胶、白芨胶及中药黄连、丹参的提取物为原料,制备一种海绵状多孔材料,研究其与细胞的相容性熏为该产品作为创面敷料修复材料和皮肤、肌腱组织工程支架材料提供实验依据。方法将中药提取液复合到明胶和白芨胶支架材料中,通过冷冻干燥法制备成海绵状多孔材料熏以L-929细胞作为对象熏利用浸提液培养及材料表面直接培养法研究该材料的细胞相容性。结果载药材料在第2、4、7天的细胞相对增殖度在100.9%～111.3%范围内,其细胞毒性级别为0级;通过L-929细胞与明胶/白芨胶载药材料复合培养第2、7天的扫描电镜观察,L-929细胞在该材料上能很好地贴附、生长。结论明胶/白芨胶载药多孔材料有良好的细胞相容性,是可以安全使用的创面修复和皮肤、肌腱组织工程用材料。     

新型复合生物抗菌敷料的抗菌强度、吸湿能力及细胞毒性

背景：细菌感染是影响伤口愈合的主要因素之一,伤口渗出液里含有的大量炎症因子、蛋白酶和自由基都会减缓伤口的愈合速度。新型复合生物抗菌敷料的研发对治疗外科感染伤口有重要的意义,是创伤敷料发展的必然趋势。 目的：观察添加纳米银的海藻酸钙敷料的抗菌活性、吸湿能力及细胞毒性。 方法：将纳米银材料添加到海藻酸钙中制备新型复合生物抗菌敷料,并通过使用平板计数法、MTT法、电子显微镜观察法观察敷料的抗菌活性、吸湿能力及细胞毒性,再与银离子海藻酸钙敷料和海藻酸钙敷料进行对比,以期显示出新型复合生物抗菌敷料的具有强抗菌性及低细胞毒性的优势。 结果与结论：与银离子海藻酸钙敷料和海藻酸钙敷料相比,添加纳米银的新型复合生物抗菌敷料对金黄色葡萄球菌、铜绿假单胞菌均有更强的抑菌作用(P < 0.01),细胞毒性较低(P < 0.01);3种敷料的吸湿能力差异无显著性意义。证实此添加纳米银的海藻酸钙敷料的具有强抗菌性及低细胞毒性。      

胶原/壳聚糖止血敷料在外科伤口中的应用

背景：壳聚糖与胶原联合可更有效地止血。 目的：评价胶原/壳聚糖止血敷料的材料学性能及应用于外科伤口的生物相容性。 方法：以“生物材料,止血敷料,纱布,胶原/壳聚糖,生物相容性”为中文关键词,以“biomaterial;hemostatic material;bioresorbable material;hemostasis effect;hemostatic mechanism”为英文关键词,采用计算机检索2000-01/2010-06与生物敷料、胶原/壳聚糖止血材料在伤口或创面止血过程中应用相关的文献。 结果与结论：壳聚糖独特的生物学特性,具有广谱抑菌、促进上皮细胞生长及止血,促进创面愈合的作用,在体内具有良好的生物降解性与组织相容性,可用于指端损伤和肉芽创面的治疗,如制成伤口敷料、可吸收缝线、止血材料、防粘连剂、药物缓释及组织工程支架,用于平战时伤口的处理。     

海藻酸钙/聚组氨酸微胶囊的毒性试验研究

为了考察海藻酸钙/聚组氨酸微胶囊的毒性特征,我们利用MTT比色法和小鼠尾静脉注射法,分别考察了该微胶囊的细胞毒性和急性全身毒性。结果表明：微胶囊浓度≤1.0mg/mL时,材料对L929细胞生长无明显抑制作用;微胶囊浸提液即使在高浸提比（10.0mg/mL）下,浸提产物也无细胞毒性作用。急性全身毒性试验结果显示：微胶囊浸提液不引起急性全身毒性反应,表明微胶囊浸提液无有毒的沥滤物和降解产物产生。说明海藻酸钙/聚组氨酸微胶囊无明显毒性。     

Assessment in vitro of the active hemostatic properties of wound dressings

The development of actively hemostatic wound dressings for use in severe trauma remains a major public-health and military goal. But, although some manufacturers claim that existing dressings activate platelets and/or blood coagulation, mechanistic evidence is often lacking. We describe a method for assessing the active hemostatic properties of dressings in vitro, entailing measurement of the flow of recalcified platelet-rich plasma (PRP) through a dressing sample. If the dressing is hemostatically active, flow is reduced. This flow is then compared with the flow-through of PRP in which both platelet and coagulation function are blocked with EDTA. The ratio of the two generates a hemostatic index that ranges from 1.0 (no active hemostasis) to 0 (highly potent). The method is applicable to porous or semiporous dressings, whether fabric, sponge, fleece, or granules. For an active dressing, the test is easily modified to differentiate between the contributions of platelet and coagulation to overall hemostasis. The method is illustrated for fabrics, over-the-counter gauze and sponge dressings, collagen-based sheets, and an absorbent granule dressing. One active collagen dressing is used to illustrate discrimination between platelet and coagulation function. The ability to assess hemostatic properties may significantly enhance the development of advanced active dressings.     

介孔二氧化硅微球的淀粉复合止血敷料

背景：止血是外伤急救的重要环节。 目的：研制一种新型的介孔二氧化硅微球/淀粉复合止血敷料,并观察其止血效果。 方法：采用溶胶-凝胶法,以三嵌段共聚物pluronic(P123)为模板剂,合成孔径在5 nm左右的介孔氧化硅微球,将其与淀粉复合,制备介孔氧化硅微球/淀粉复合止血敷料,通过动物实验观察复合材料的止血性能。 结果与结论：介孔氧化硅微球/淀粉复合材料不仅具有很强的吸水性能,而且还具有明显的体外凝血性能,能显著地缩短部分凝血活酶时间和凝血酶原时间。介孔氧化硅微球/淀粉复合材料能够阻止兔背部皮肤及肝脏伤口的流血和缩短其流血时间,具有明显的止血效果。     

Development of a chitosan-based wound dressing with improved hemostatic and antimicrobial properties

Hemorrhage remains a leading cause of early death after trauma, and infectious complications in combat wounds continue to challenge caregivers. Although chitosan dressings have been developed to address these problems, they are not always effective in controlling bleeding or killing bacteria. We aimed to refine the chitosan dressing by incorporating a procoagulant (polyphosphate) and an antimicrobial (silver). Chitosan containing different amounts and types of polyphosphate polymers was fabricated, and their hemostatic efficacies evaluated in vitro. The optimal chitosan-polyphosphate formulation (ChiPP) accelerated blood clotting (p = 0.011), increased platelet adhesion (p=0.002), generated thrombin faster (p = 0.002), and absorbed more blood than chitosan (p < 0.001). Silver-loaded ChiPP exhibited significantly greater bactericidal activity than ChiPP in vitro, achieving a complete kill of Pseudomonas aeruginosa and a > 99.99% kill of Staphylococcus aureus consistently. The silver dressing also significantly reduced mortality from 90% to 14.3% in a P. aeruginosa wound infection model in mice. Although the dressing exerted severe cytotoxicity against cultured fibroblasts, wound healing was not inhibited. This study demonstrated for the first time, the application of polyphosphate as a hemostatic adjuvant, and developed a new chitosan-based composite with potent hemostatic and antimicrobial properties.     

A self-assembling hydrophobically modified chitosan capable of reversible hemostatic action

Blood loss at the site of a wound in mammals is curtailed by the rapid formation of a hemostatic plug, i.e., a self-assembled network of the protein, fibrin that locally transforms liquid blood into a gelled clot. Here, we report an amphiphilic biopolymer that exhibits a similar ability to rapidly gel blood; moreover, the self-assembly underlying the gelation readily allows for reversibility back into the liquid state via introduction of a sugar-based supramolecule. The biopolymer is a hydrophobically modified (hm) derivative of the polysaccharide, chitosan. When hm-chitosan is contacted with heparinized human blood, it rapidly transforms the liquid into an elastic gel. In contrast, the native chitosan (without hydrophobes) does not gel blood. Gelation occurs because the hydrophobes on hm-chitosan insert into the membranes of blood cells and thereby connect the cells into a sample-spanning network. Gelation is reversed by the addition of α-cyclodextrin, a supramolecule having an inner hydrophobic pocket: polymer hydrophobes unbind from blood cells and embed within the cyclodextrins, thereby disrupting the cell network. We believe that hm-chitosan has the potential to serve as an effective, yet low-cost hemostatic dressing for use by trauma centers and the military. Preliminary tests with small and large animal injury models show its increased efficacy at achieving hemostasis - e.g., a 90% reduction in bleeding time over controls for femoral vein transections in a rat model.     

可溶性止血纱布对兔肝脏创伤的止血作用

BACKGROUND: Modified cellulose dressing as an important part of polysaccharide hemostatic material has its unique advantages compared with gelatin sponge and fibrin glue. OBJECTIVE: To compare the hemostatic effect and histocompatibility of medical gauze, absorbable hemostatic gauze and soluble hemostatic gauze.  METHODS: After establishment of liver trauma models, 36 New Zealand rabbits were randomly divided into three groups (n=12) depending on different hemostatic materials. Injury wounds were covered with soluble hemostatic gauze (mainly made of sodium carboxymethyl cellulose, experimental group), absorbable hemostatic gauze (mainly made of sodium carboxymethyl cellulose, control group) and medical gauze (normal group), respectively. The gauze was only taken out in the normal group. A hemostasis trial on liver injury was carried out to investigate the bleeding time and bleeding amount. After 1, 3, 7 and 10 days, wound healing was observed histologically in each group.  RESULTS AND CONCLUSION: The bleeding time and bleeding amount in the experimental and control groups were lower than those in the normal group (both P < 0.05), but no statistical difference was found between the experimental and control groups. After 1 day of implantation, the soluble hemostatic gauze was absorbed completely, and the absorbable hemostatic gauze was absorbed with no residual until the 10th day. Experimental and control groups shared similar pathological changes. In these two groups, mild fibrosis and fibrous scar appeared, a better improvement in wound inflammation was shown at 10 days compared with that at 7 days, and the wound gradually healed. In the normal group, there were no obvious lesions except mild tissue edema around the wound. All these findings suggest that the soluble hemostatic gauze has better hemostatic effect and histocompatibility.     

Structural design of the dry fibrin sealant dressing and its impact on the hemostatic efficacy of the product

We compared the hemostatic efficacy of a production version of a dry fibrin sealant dressing (DFSD) to a prototype that was previously successful in large animal studies. The results were used to improve manufacturing processes. Grade-V liver injuries were induced in swine and treated with gauze sponges (GAU), the prototype dressings (DFSD-1), or the scaled-up production version dressings (DFSD-2 in experiment 1 and DFSD-3 in experiment 2). Blood loss, hemostasis, resuscitation volume, and 60-min survival were quantified. In experiment 1, the DFSD-1 treatment reduced blood loss (p < 0.01), increased hemostasis at 4 min (p < 0.05), and improved survival (p < 0.05) compared with GAU. The DFSHD-2 decreased blood loss (p < 0.05) but did not increase hemostasis or survival significantly. Based on these results, manufacturing processes were altered, producing DFSD-3. In experiment 2, the DFSD-1 and DFSD-3 were equally effective in reducing blood loss (p < 0.01) and resuscitation volume (p < 0.05) compared with GAU. Hemostasis occurred more frequently in both the DFSD-1 and DFSD-3 groups (p < 0.01) compared with GAU. The structural design of DFSD-2 did not meet the efficacy requirement for release of the product. The subsequent change incorporated in DFSD-3 improved all hemostatic parameters of the dressings equal to those of the prototype product.     

三种创面敷料在薄中厚皮片供皮区的应用研究

目的观察3种创面敷料对薄中厚皮片供皮区创面愈合的影响。 方法选取蚌埠医学院第一附属医院整形烧伤科2020年1月至12月收治的38例自体皮片移植术患者。在同一患者供皮区分别取相同面积的类矩形薄中厚皮片3处,每处均间隔1 cm,每例所取皮片总面积基本相同,将同一患者的3处供皮区分为凡士林敷料组、银离子藻酸盐敷料组和丝素蛋白膜状敷料组3组,取皮后分别贴敷凡士林敷料、银离子藻酸盐敷料和丝素蛋白膜状敷料。对比3组供皮区创面积血率、初次换药时患者的疼痛程度[数字评定量表(NRS)]、创面感染率、创面上皮化愈合时间、创面后期愈合效果。对数据行单因素方差分析、t检验和χ²检验。 结果(1)创面积血率：丝素蛋白膜状敷料组创面积血率(23.68%)分别高于分别高于凡士林敷料组(2.63%)和银离子藻酸盐敷料组(5.26%),差异均有统计学意义(χ²＝ 7.370、5.208, P<0.05),凡士林敷料组与银离子藻酸盐敷料组积血率比较,差异无统计学意义(χ²＝0.347, P>0.05);(2)初次换药时疼痛程度评价：丝素蛋白膜状敷料组的NRS评分为(2.97±1.48)分,分别低于银离子藻酸盐敷料组[(3.97±1.84)分]和凡士林敷料组[(6.03±1.37)分],差异均有统计学意义(t＝ 4.854、0.873, P<0.05);银离子藻酸盐敷料组疼痛评分低于凡士林敷料组,差异有统计学意义(t＝1.467, P<0.05);(3)创面感染率：银离子藻酸盐敷料组创面感染率(5.26%)分别与丝素蛋白膜状敷料组(0)和凡士林敷料组(10.53%)比较,差异均无统计学意义(χ²＝ 2.054、0.724, P>0.05);丝素蛋白膜状敷料组与凡士林敷料组比较,感染率低,差异有统计学意义(χ²＝ 4.222, P<0.05);(4)创面上皮化愈合时间：丝素蛋白膜状敷料组创面上皮化愈合时间为(8.95±1.34) d,与银离子藻酸盐敷料组[(13.69±1.64) d]以及凡士林敷料组[(11.78±1.43) d]比较,愈合时间均较短,差异均有统计学意义(t＝0.953、1.204, P<0.05)。与银离子藻酸盐敷料组比较,凡士林敷料组愈合时间短,差异有统计学意义(t＝2.147, P<0.05);(5)创面后期愈合效果：3组在瘢痕增生和色素沉着2方面均无明显差异。 结论丝素蛋白膜状敷料应用于薄中厚皮片供皮区,具有相对无痛、抗感染能力强、上皮化愈合时间短等优势,但在防止创面积血方面效果欠佳。     

Wound dressing composed of hyaluronic acid and collagen containing EGF or bFGF: comparative culture study

We developed a novel wound dressing composed of a hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) or basic fibrolast growth factor (bFGF) by freeze-drying method (EGF-wound dressing or bFGF-wound dressing, respectively). A wound dressing without any growth factor was prepared as a control in a similar manner as above (C-wound dressing). Intermolecular cross-linkage between Col molecules was induced by UV irradiation. The release behavior of free HA from the wound dressing was investigated using a C-wound dressing. The weight of C-wound dressing after 1 day, 3, 5, and 7?days of incubation on top of a Col gel sheet at the air–water interface (wound surface model) was 55, 36, 30, and 19% of the original weight, respectively. Most free HA and a part of Col was released from the cross-linked Col network in the wound dressing during incubation, as the original Col content in the wound dressing was 33%. Next, fibroblast proliferation was assessed in conventional culture medium preconditioned by immersion of a piece of C-, EGF-, or bFGF-wound dressing, i.e. C-conditioned medium, EGF-conditioned medium, or bFGF-conditioned medium. Cell proliferation in C-conditioned medium increased to approximately the same level as that in conventional medium. Cell proliferation in EGF- and bFGF-conditioned medium was 1.9 times and 2.6 times greater than that in conventional medium after 7?days of cultivation, respectively. Finally, cytokine production of fibroblasts was assessed in a wound surface model using a fibroblast-incorporating Col gel sheet (cultured dermal substitute [CDS]). CDS was elevated to the air–medium interface, on which each wound dressing was placed and cultured for 7?days. Fibroblasts in CDS covered with EGF-wound dressing released 3.6 times more vascular endothelial growth factor (VEGF) and 4.6 times more hepatocyte growth factor (HGF) when compared with the C-wound dressing. Fibroblasts in CDS covered with bFGF-wound dressing released 10.2 times more VEGF and 6.3 times more HGF when compared with the C-wound dressing. This finding indicates that bFGF-wound dressing can facilitate more effectively the VEGF and FGF production compared with EGF-wound dressing.     

Potential of wound dressing composed of hyaluronic acid containing epidermal growth factor to enhance cytokine production by fibroblasts

This study aimed to investigate the potential of a wound dressing composed of hyaluronic acid (HA) containing epidermal growth factor (EGF) to enhance cytokine production by fibroblasts. The present wound dressing has a two-layered spongy structure: an upper layer composed of crosslinked high-molecular-weight HA, and a lower layer composed of low-molecular-weight HA containing arginine (Arg) and vitamin C derivative (VC) with or without EGF. Human fibroblast-embedded collagen gel sheet (cultured dermal substitute: CDS) was elevated to the interface between the air and culture medium to create a wound surface model onto which each wound dressing was placed, which was followed by culture for 7 days. The EGF dressing (with EGF, Arg, VC) significantly enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by CDS as compared to the EGF-free dressing (with Arg, VC). To evaluate if this enhanced production of VEGF and HGF achieved with the EGF dressing is sustained, a second experiment was conducted using a wound surface model. Each wound dressing was placed on the CDS in the wound surface model. Culture was then performed for 3 days (first period), after which each dressing was placed on another CDS for a further 3-day culture period (second period). The EGF dressing enhanced the production of VEGF and HGF by CDS during the first and second periods as compared to the corresponding production when using the EGF-free dressing. These results suggest that EGF can be maintained in the hydrated layer of a wound dressing composed of crosslinked high-molecular-weight HA.