兔眼角膜胶原交联后角膜动态响应参数的变化

本研究应用可视化角膜生物力学分析仪,于角膜胶原交联术前与术后3月内不同时间对兔眼角膜实施测试,探讨角膜胶原交联后,角膜动态响应参数随术后时间的变化,并计算角膜弹性模量,分析生物力学参数与中央角膜厚度、生物力学矫正眼压的相关性.研究发现,术后1周内角膜动态响应参数变化明显,术后2～3月开始趋于稳定.交联后4周角膜弹性模量...     

胶原喷剂修复兔鼻黏膜的机械损伤

背景：胶原是一种天然的低免疫原性物质,具有良好的细胞相容性和组织相容性,能促进血管生成,在细胞分化、组织修复、器官的正常营养等方面都有着极其重要的作用。 目的：评价胶原喷剂对新西兰兔鼻黏膜机械损伤的修复作用。 方法：制备鼻黏膜机械损伤模型,给予治疗组左鼻胶原喷剂,模型组左鼻同量生理盐水,观察创伤部位的修复情况及鼻黏膜的病理变化。 结果与结论：胶原喷剂无刺激性。治疗组杯状细胞计数、黏膜下腺体与模型组比较有降低趋势,但差异无显著性意义。治疗组黏膜下水肿情况与模型组比较明显减轻,差异有显著性意义(P < 0.01)。组织形态学观察结果发现,新生修复的上皮杯状细胞数量减少,黏膜下腺体为小圆形,形态规则,分泌通畅,无明显水肿,且腺体密集;模型组则无上述改变。提示胶原喷剂对黏膜损伤具有明显的修复作用,黏膜固有层炎细胞浸润现象减轻,无明显弥漫性黏膜下水肿表现,腺体分泌情况良好。     

壳聚糖-胶原角膜修复材料的制备及生物相容性

背景：将胶原和壳聚糖按一定比例制成复合膜后,能够降低壳聚糖的正电荷,改善壳聚糖的吸附力,促进细胞的黏附生长、迁移和增殖,增强壳聚糖的生物学性能,成为十分优良的生物材料。 目的：制备壳聚糖-胶原复合膜,观察其与角膜基质层的组织相容性。 方法：制作壳聚糖-胶原复合膜材料。将16只新西兰兔随机分为两组,实验组于右眼角膜基质袋内植入壳聚糖-胶原复合膜,对照组右眼角膜基质袋内植入壳聚糖膜。移植后进行裂隙灯显微镜、前节-光学相干断层成像及组织学观察。 结果与结论：①裂隙灯显微镜：移植后第8周,实验组膜片中央出现降解浸润,皱褶屈曲不明显;对照组膜片全部浸润,皱褶屈曲明显。②前节-光学相干断层成像：移植后第6周,实验组的复合膜边界模糊,密度与正常角膜组织很接近,角膜形态恢复正常。③组织学观察：移植后第8周,实验组膜片表层少量降解,降解材料与角膜基质融合,膜片周围角膜基质有少量炎性细胞浸润;对照组膜片表层降解程度大于实验组,降解物质与角膜基质交织融合,膜片周围角膜基质有较多炎性细胞浸润。表明壳聚糖-胶原复合膜具有可降解性和良好的组织相容性。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     

制备工艺条件对胶原多孔支架材料结构和性质的影响

目的考察胶原溶胀液浓度、预冻温度等制备工艺条件对胶原多孔支架结构和性质的影响。方法采用冷冻干燥法制备胶原多孔支架,分别以不同浓度(0.2%～0.8%)的胶原溶胀液,经-50℃预冻制备;同时选择0.6%胶原溶胀液,分别经不同预冻温度(-20～-80℃)预冻制备。以甲醛为交联剂对胶原多孔支架进行化学交联。考察不同制备条件下制备的胶原多孔支架孔径结构、力学强度和降解率等性质,同时将兔关节软骨细胞种植在胶原多孔支架上,应用MTT法和扫描电镜观察比较其细胞相容性。结果随着胶原溶胀液浓度增加,多孔支架平均有效孔径逐渐减小,分布更加不均,孔径范围为50～200μm之间,支架的密度和抗拉强度逐渐增加,降解率逐渐减小;随着预冻温度的降低,胶原多孔支架孔径逐渐减小,分布更均一,降解率逐渐减小。细胞培养结果显示,胶原溶胀液浓度的减低和预冻温度的升高,制备的支架有利于软骨细胞黏附和增殖,电镜观察支架上细胞形态呈球形,有大量的丝状伪足相连。结论在不同的胶原溶胀液浓度和预冻温度的制备条件下制备的胶原多孔支架具有不同孔径结构,进而影响到胶原多孔支架的力学性能,降解性能和细胞相容性等。在本实验所选择孔隙尺寸范围内,孔径越大越有利于软骨细胞的黏附和增殖,胶原溶胀液浓度为0.3%～0.6%和预冻温度为-30～-50℃胶原多孔支架适合软骨细胞的黏附和增殖。     

脱细胞猪角膜基质的基底膜在修复兔角膜损伤中的作用

目的 探讨脱细胞角膜基质支架材料表面保存基底膜样结构对修复角膜损伤的必要性. 方法 将采用反复冻融及酶消化法制备的脱细胞猪角膜基质,移植到兔角膜损伤模型上,通过大体及组织学分别观察材料表面基底膜结构的有无对修复兔角膜基质损伤的影响. 结果 脱细胞猪角膜基质材料表面有基底膜的实验组（n=8）兔角膜损伤全部修复,无穿孔,支架材料与受体角膜整合.材料表面无基底膜的对照组（n=8）中,有6例植入的支架材料溶解,兔角膜穿孔.两组结果比较差异有显著统计学意义. 结论 脱细胞角膜基质支架材料表面具有基底膜样结构,有利于形成正常角膜上皮屏障,从而防止了生物材料的过快降解,有利于材料与宿主基质的整合和改建.     

细胞悬液移植技术在创面修复中的研究与应用进展

由各类因素所导致的急性、慢性、难愈性及医源性创面在临床上十分常见,常严重影响患者的生活质量并增加患者经济及社会医疗负担。随着细胞悬液移植相关的制备技术和载体材料研究趋渐成熟,其降低供皮区面积、治疗效果明确等优点使得自体/异体细胞应用于皮肤创面的治疗研究成为近年来创面修复临床研究的热点之一。但细胞悬液制备技术和载体技术目前尚无统一标准且部分技术尚未进行严格临床研究验证,仍需进行进一步临床研究明确其疗效及适应证。本文从细胞悬液的制备、移植及临床应用3个方面,对细胞悬液移植技术在创面修复方面的研究与应用进行归纳整理,以期为临床及科研工作者提供参考依据。     

无细胞胶原基质的研究进展

天然胶原类组织,经过脱细胞处理后,降低免疫原性,可作为组织工程的支架材料,本文就脱细胞的方法以及无细胞胶原基质的研究进展作一综述。     

胶原基真皮再生支架的微结构控制

综述了影响胶原基真皮再生支架微结构的各种因素及其控制方法。胶原基真皮支架的生物活性和修复创面的能力受到诸如除胶原外的其它主要材料 (第二组分 )、支架的孔径和孔隙率、支架厚度、生物活性因子以及交联度等多方面因素的综合影响。从材料学、生物学和医学的角度综合地应用物理、化学和生物学的手段探索各种影响因素的控制方法是组织工程皮肤研究的重点。     

细胞生长因子修复骨骼肌损伤

BACKGROUND: A variety of cell growth factors are involved in skeletal muscle regeneration; moreover, these factors cooperate with each other to promote muscle repair and regeneration. OBJECTIVE: To explore the synergy mechanism of a variety of cell growth factors in promoting damage repair. METHODS: By using literature survey, Wanfang, CNKI and PubMed databases were searched for articles related to exercise-induced muscle damage and repair using the keywords of “cell growth factor; skeletal muscle damage;   repair; fibroblast growth factor” in Chinese and English, respectively. Research achievements related to exercise-induced muscle damage, molecular biological characteristics of cell growth factors and skeletal muscle injury repair are discussed. RESULTS AND CONCLUSION: Basic fibroblast growth factor plays a basic biological role to promote cell proliferation and angiogenesis, which is the strongest cytokine known to promote cell growth and reflects a very important role in skeletal muscle repair. Epidermal growth factor is synthesized by monocytes and ectodermal cells, which is prominent to stimulate the division and proliferation of a variety of tissues and cells, enhance cell movement, division and synthesis of interstitial protein. Insulin-like growth factors are a family of insulin-like growth factor 1-related and insulin-like growth factor 2-related peptides, which can promote muscle protein synthesis, promote muscle cell proliferation and differentiation, and participate in skeletal muscle regeneration and repair, thereby accelerating wound healing of the muscles. Neurotrophic factor is a kind of trace soluble substances around sensory neurons and produced by neuron-targeted cells, which can specifically promote neuronal growth and maintenance, and promote skeletal muscle repair. But studies on the synergy mechanism of a variety of cell growth factors in the repair of exercise-induced muscle damage are just at the initial stage, and further research is necessary.       

肌腱损伤的修复材料

背景：目前肌腱修复研究需要解决的问题很多,如肌腱缝合与粘连的机制研究,提高肌腱愈合质量研究,缝合材料与方法的改进,肌腱缝接处的抗张强度研究,组织工程肌腱的生物材料研究等,这些都是影响肌腱修复研究发展的重要问题。 目的：通过对汤森路透Web of Science数据库收录2002/2011有关肌腱损伤修复材料相关文献的献计量学分析,评估该领域学术文献的总体趋势,为该领域的深入研究提供参考。 设计：文献计量学分析。 资料提取：由第一作者以电子检索方式对汤森路透Web of Science数据库2002-01/2011-12肌腱损伤修复材料研究的文献进行分析,采用检索词为“tendon injury(肌腱损伤),material (材料),repair (修复)”,对检索的相关文献运用数据库中自带的分析功能和Excel软件绘制图表的功能进行分析,描述其分布特征。 入选标准：纳入经同行评议的肌腱损伤修复材料研究已发表的文献,包括研究原著、综述和会议的文献类型。排除：①需采用手工检索和电话检索方式收集的文章。②未正式出版的文章。③在收录数量之外排除勘误类文献类型。 主要数据的判定指标：以SCI数据库相关文献出版时间、文献的数量、学科分类、文献类型、发文量较多的作者、来源出版物、会议、发文量较多的机构、国家地区分布、基金资助情况、文献语种和被引频次进行分析。 结果：①汤森路透Web of Science数据库过去10年共收录肌腱损伤修复材料研究相关文献156篇。从文献发表数量的趋势上看,总体呈现出逐步上升的状态,2009年收录该领域的相关文献达到顶峰,为28篇。其中研究原著类文章共收录141篇,综述类文章13篇。研究文字的学科领域集中在骨科学和外科学方向,其次为运动科学和工程学。②目前发表量较多的出版物为American Journal of Sports Medicine《美国运动医学杂志》、Foot Ankle International《足与踝国际杂志》和Archives of Orthopaedic and Trauma Surgery《矫形外科与创伤外科学文献集》。发表文献的国家以美国为主,占全球相关领域发稿量的42.9%。中国在过去10年间被收录文章总量位居第5名,共发表9篇相关文章,占全球相关文章的5.8%。③肌腱损伤修复材料研究相关文献的基金以NIH资助为主。最高被引频次文章主要发表在Journal of Cellular Physiology《细胞生理学杂志》和Cytokine & Growth Factor Reviews《细胞分裂与生长因子评论》等期刊上。 结论：文献分析显示,近几年来肌腱损伤修复材料的研究趋于成熟,发文量稳定并且呈逐渐上升趋势,是目前骨科、外科和运动医学领域的研究热点。       

The lectin KM+ induces corneal epithelial wound healing in rabbits

Neutrophil influx is essential for corneal regeneration ( Gan et al. 1999 ). KM+, a lectin from Artocarpus integrifolia , induces neutrophil migration ( Santos-de-Oliveira et al. 1994 ). This study aims at investigating a possible effect of KM+ on corneal regeneration in rabbits. A 6.0-mm diameter area of debridement was created on the cornea of both eyes by mechanical scraping. The experimental eyes received drops of KM+ (2.5 μg/ml) every 2 h. The control eyes received buffer. The epithelial wounded areas of the lectin-treated and untreated eyes were stained with fluorescein, photographed and measured. The animals were killed 12 h (group 1, n  = 5), 24 h (group 2, n  = 10) and 48 h (group 3, n  = 5) after the scraping. The corneas were analysed histologically (haematoxylin and eosin and immunostaining for proliferation cell nuclear antigen, p63, vascular endothelial growth factor, c-Met and laminin). No significant differences were found at the epithelial gap between treated and control eyes in the group 1. However, the number of neutrophils in the wounded area was significantly higher in treated eyes in this group. Three control and seven treated eyes were healed completely and only rare neutrophils persisted in the corneal stroma in group 2. No morphological distinction was observed between treated and control eyes in group 3. In treated corneas of group 2, there was an increase in immunostaining of factors involved in corneal healing compared to controls. Thus, topical application of KM+ may facilitate corneal epithelial wound healing in rabbits by means of a mechanism that involves increased influx of neutrophils into the wounded area induced by the lectin.     

Neuregulin-1 accelerates corneal epithelial wound healing

Corneal epithelial cells (CECs) play an important role in the function of the cornea, and are maintained by corneal epithelial stem cells (CESCs). Recent studies have shown that neuronal growth factors affect the proliferation and migration of CESCs. Neuregulin-1 (NR-1) is a neuronal growth factor that is expressed in the early stages of brain development. The aim of this study was to determine whether NR-1 activates corneal wound healing. We observed that NR-1 activated both proliferation and migration of CECs. In addition, the colony-forming efficacy of CESCs was enhanced. In mice, NR-1 treatment improved corneal wound healing. Furthermore, the expression of markers of corneal epithelium maintenance (ΔNp63) and CESC proliferation (Bmi-1 and Abcg2) was increased. These effects were mediated by intracellular signalling pathways (Stat3, Erk1/2 and p38). Taken together, our results suggest that NR-1 accelerates the recovery of corneal wounds, and may represent a novel treatment for corneal damage.     

Comparative biochemical and morphometric studies on corneal wound healing

Comparative biochemical and morphological studies were carried out on wounded corneas in order to correlate biochemical findings with morphometric observations during the healing process. Experimental production of corneal wounds, biochemical determinations and quantitative morphometric studies are described in an attempt to correlate corneal matrix macromolecules biosynthesis during the healing process with the morphological modifications of the tissue. The central part and the peripheral part of the corneas were examined separately and compared to the central and peripheral parts of the controlateral corneas. The DNA content of the central portion of the wounded corneas progressively increased and reached after 60 days the same level as the corresponding portion of the controlateral corneas. The DNA contents of the peripheral portions of wounded and controlateral corneas are persistently higher than the DNA contents in the central portion. In peripheral portions of wounded corneas the DNA content is higher than in controlateral corneas and continues to increase steadily during the 60 days of experimentation. Cell density, as determined by morphometry, increased also during that period. The differences between the evolution of the DNA contents and cell density curves may be attributed to variations in cell sizes. The collagen content, estimated from hydroxyproline determinations remained lower in the wounded corneas as compared to the controlateral corneas, even 60 days after operation. This was true for the central as well as for the peripheral portions, suggesting a collagenolytic process as a result of wounding. This is confirmed by morphometric evaluation of fiber density.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lymphocyte function-associated antigen-1-dependent inhibition of corneal wound healing

Abrasion of murine corneal epithelium induces neutrophil emigration through limbal vessels into the avascular corneal stroma, peaking within 12 to 18 hours after wounding. A central corneal wound closes within 24 hours by epithelial cell migration and division, and during wound closure corneal epithelial cells express intercellular adhesion molecule (ICAM)-1 (CD54). We investigated the contributions of lymphocyte function-associated antigen (LFA)-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) by analyzing wound closure in mice with targeted deletions of CD11a (CD11a-/-) or CD11b (CD11b-/-). In contrast to CD11a-/- mice, CD11b deficiency revealed a much greater delay in epithelial wound closure with >90% inhibition of epithelial cell division at a time when neutrophil accumulation in the cornea was approximately threefold higher than normal. Treating CD11b-/- mice with anti-CD11a monoclonal antibody at the time of epithelial abrasion resulted in significant reductions in neutrophils and significant increases in corneal epithelial cell division and migration. Treating CD11b-/- mice with anti-ICAM-1 significantly increased measures of healing but marginally reduced neutrophil influx. In conclusion, wound healing after corneal epithelial abrasion is disrupted by the absence of CD11b. The disruption is apparently linked to excessive neutrophil accumulation at a time when epithelial division is essential to wound repair, and neutrophils appear to be detrimental through processes involving LFA-1 and ICAM-1.     

Acidic fibroblast growth factor overexpression in corneal epithelial wound healing.

aFGF expression was studied in normal and regenerating cornea of adult rats. aFGF mRNA and proteins were expressed mainly in corneal epithelium but not in stroma. After burning of the epithelium by iodine vapours, the intact epithelial cells migrated to cover the wounded area during the first 4 days and then divided to reconstitute a normal multilayered epithelium 6 days after injury. aFGF mRNA localized by in situ hybridization on regenerating epithelium showed a peak between 6 hr and 2 days after denudation, decreasing to basal levels 6 days later. This induction of aFGF mRNA preceded the increased amount of aFGF peptides, as assessed by indirect immunofluorescence staining. Thus aFGF overexpression is clearly correlated with active migration in epithelial wound healing.     

Bioactive interpenetrating polymer network hydrogels that support corneal epithelial wound healing

The development and characterization of collagen-coupled poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) interpenetrating polymer network hydrogels is described. Quantitative amino acid analysis and FITC-labeling of collagen were used to determine the amount and distribution of collagen on the surface of the hydrogels. The bioactivity of the coupled collagen was detected by a conformation-specific antibody and was found to vary with the concentration of collagen reacted to the photochemically functionalized hydrogel surfaces. A wound healing assay based on an organ culture model demonstrated that this bioactive surface supports epithelial wound closure over the hydrogel but at a decreased rate relative to sham wounds. Implantation of the hydrogel into the corneas of live rabbits demonstrated that epithelial cell migration is supported by the material, although the rate of migration and morphology of the epithelium were not normal. The results from the study will be used as a guide toward the optimization of bioactive hydrogels with promise in corneal implant applications such as a corneal onlay and an artificial cornea.     

A study of the proliferative properties of corneal tissues during wound healing

Summary The process of healing of the injured cornea was investigated in rabbits. This process was followed up for the period ranging from 1 hr to 30 days after infliction of the injury. Biphasic course of regeneration of the epithelium and migration of cells from the epithelial layer to the border zone was not revealed. It was demonstrated that the structure of the epithelial wedge depended on the conditions of the experiment. Connective tissue possesses a lower reactivity than epithelium and it regenerates with its own cells. When the wound is inflicted near the limbus the elements of the latter may take part in its regeneration.Presented by Active Member Acad. Med. Sci. USSR N. G. Khlopin     

扰乱昼夜节律对小鼠角膜创伤修复的影响

目的:本研究旨在观察昼夜节律对角膜创伤修复的影响。方法:选用C57BL/6雄性小鼠,在小鼠角膜中央直径为2 mm的圆形区域,用高尔夫样刀机械性去除其上皮层,使用荧光素钠显色创伤面积,动态观察上皮层修复的动力学,并观察白细胞、血小板和分裂细胞的动态变化。结果:全昼(12 h light/12 h light,LL)和全夜(12 h dark/12 h dark,DD)组角膜创伤修复速率小于对照组(12 h light/12 h dark,LD),表现为再上皮化延迟、上皮细胞数量降低、血管扩张直径增大、白细胞和血小板募集的发生延迟,但白细胞和血小板数目显著增多。结论:扰乱昼夜节律延迟炎症反应的发生,但加剧炎症反应;延迟再上皮化过程,最终显著抑制角膜创伤修复过程。