角膜缘干细胞识别的研究进展

角膜干细胞存在于角巩膜缘被人们所认识已有20年了。随着对角膜缘干细胞研究的深入，发现其对角膜的完整性及功能至关重要。正常情况下角膜缘干细胞具有上皮屏障的作用，能阻止结膜上皮及血管向角膜内生长。角膜缘干细胞缺乏将导致各种眼表功能异常。角膜缘干细胞的定位和分离，对临床上应用角膜缘干细胞移植治疗各种眼表异常具有重要意义。就国内外对角膜缘干细胞识别的研究做一综述。     

角膜缘干细胞在重建眼表中的作用研究进展

正常角膜上邓小平的完整性依赖于基底层角膜缘干细胞的不断增殖。角膜缘于细胞对角膜上皮的再生起着重要的作用。如果角膜缘干细胞因各种原因严重缺乏，会导致持续性角膜上皮糜烂、角膜新生血管和假性翼状胬肉形成，角膜的完整性和透明性将受到破坏。本对角膜缘干细胞的性质、特点、分布、检测、各种干细胞移植术、干细胞的体外培养及其适宜的载体等进行综述，以便对角膜缘干细胞进行更深入的研究。     

角膜缘干细胞培养体系的研究进展

正常角膜上皮形态稳定和功能的维持是依靠角膜缘干细胞的不断增殖和移行来实现。近年来，角膜缘干细胞的重要作用逐渐被人们所认识。本文从角膜缘干细胞的定位、体外取材、分离培养、培养条件的选择、常用体外培养的载体、鉴别方法等对角膜缘干细胞培养体系进行综述。     

角膜缘干细胞微环境的研究进展

角膜上皮的更新及损伤后修复有赖于角膜缘干细胞功能正常.角膜缘干细胞的增生及相关特性受干细胞微环境的调控影响.近年研究表明,角膜缘干细胞微环境包括干细胞龛三维结构、干细胞龛中存在的各种细胞类型、细胞分泌的细胞因子及角膜缘特异的基底膜.其中角膜缘细胞外基质和邻近细胞对角膜缘干细胞的调节尤为重要.模拟角膜缘干细胞微环境构建组织工程角膜对实现眼表重建,为患者带来复明希望具有重要意义.     

不同体外方法培养兔角膜缘上皮细胞作用的研究

自从1986年Schermer等发现角膜缘干细胞位于角膜缘基底Vogt栅栏内后，对角膜缘干细胞缺失和角膜上皮病变治疗有了许多新的疗法，其中以角膜缘上皮细胞体外培养法治疗上述疾病比较有效。目前，多数学者采用组织块法进行角膜缘上皮细胞体外培养，但在培养系中干细胞能否从组织块中迁移出来尚有争议。另外，最近角膜缘上皮单细胞悬浮液超低温冷藏、复苏以及体外培养技术越来越受到人们的关注，成为角膜缘干细胞研究中的一项重要的课题。此种培养方法既可以将角膜缘干细胞和其他角膜上皮细胞长期保存在超低温状态下，减少细胞传代培养次数，[第一段]     

角膜缘干细胞培养及研究进展

角膜缘干细胞是一种特殊类型的细胞,位于角膜缘基底上皮层,在角膜上皮更新和创伤愈合中起重要作用。对于角膜缘干细胞缺乏或功能障碍的疾病,培养角膜缘干细胞进行移植将是一种重要且有效的治疗方法。对角膜缘干细胞的生物学特性和解剖定位、影响培养的干细胞增殖的调控因素、培养的角膜缘于细胞移植、移植所需载体的选择等方面的研究进展作一综述。     

培养角膜缘干细胞移植重建眼表的研究进展

角膜缘干细胞缺乏所致眼表疾病已成为角膜病致盲的重要原因之一。随着细胞培养技术的发展,角膜缘干细胞的重要作用已经得到了极大的肯定。角膜缘干细胞体外培养后移植是治疗眼表疾病的重要途径。本文就其组织学定位、培养载体和基础研究做一综述,以便对角膜缘干细胞有更深入的研究。     

角膜缘干细胞在重建眼表中的作用研究进展

正常角膜上皮的完整性依赖于基底层角膜缘干细胞的不断增殖。角膜缘干细胞对角膜上皮的再生起着重要的作用。如果角膜缘干细胞因各种原因严重缺乏 ,会导致持续性角膜上皮糜烂、角膜新生血管和假性翼状胬肉形成 ,角膜的完整性和透明性将受到破坏。本文对角膜缘干细胞的性质、特点、分布、检测、各种干细胞移植术、干细胞的体外培养及其适宜的载体等进行综述 ,以便对角膜缘干细胞进行更深入的研究。     

角膜缘干细胞移植治疗角膜疾病的研究进展

角膜缘干细胞在维持正常角膜上皮完整性以及角膜损伤修复中有重要作用.角膜缘干细胞损伤所致的角膜缘干细胞缺失可导致严重的角膜病变.目前治疗角膜缘干细胞缺失的主要方法是细胞移植治疗.本文就角膜缘干细胞的体外培养、鉴定、移植方法以及新的细胞来源等问题进行综述.     

角膜缘干细胞培养后移植的研究进展

眼表的许多疾病都是由于角膜缘干细胞功能障碍引起，角膜缘干细胞培养后移植是治疗角膜缘干细胞功能障碍的有效手段。本文将对培养的角膜缘干细胞移植的材料，角膜缘干细胞培养后自体和异体移植以及移植术后的处理等方面的研究作一简要综述。     

Perspektiven und aktueller Stand der Limbusstammzelltransplantation

The transplantation of limbal stem cells is one of the most challenging surgical approaches in ocular surface reconstruction. Partial and unilateral limbal stem cell insufficiency (LSCI) can be treated by fractionated abrasion or autologous limbal stem cell transplantation from the fellow eye. In cases of advanced bilateral and partial LSCI, ex vivo expansion of limbal stem cells on amniotic membranes or fibrin can be performed but all patients with complete bilateral LSCI must rely on allogenic limbal stem cell transplantation with high immunological risks. Attempts to combine allogenic limbal stem cell transplantation with mitomycin C and amniotic membrane transplantation are promising. In the laboratory, attempts to transdifferentiate bone marrow stem cells into corneal epithelial cells have been without success. Nonetheless, transdifferentiation of hair follicle stem cells into corneal epithelial cells looks promising. In parallel, research on the limbal stem cell niche is ongoing to elucidate the natural environment of limbal stem cells in order to improve ex vivo culture.     

培养兔自体角膜缘干细胞移植的实验研究

目的 观察以羊膜为载体的兔角膜缘于细胞膜片移植治疗兔角膜缘于细胞缺损的效果。方法 制造兔角膜缘干细胞缺损的动物模型,以右眼为实验眼,从兔左眼取角膜缘组织,将兔角膜缘干细胞消化下来,接种于铺有羊膜的无菌六孔培养板中,待细胞形成多层角膜上皮细胞后,对兔角膜缘干细胞缺损动物模型行角膜缘干细胞羊膜移植术,并对治疗后的角膜进行裂隙灯及病理学检查。结果 临床和组织病理学染色证实：体外培养的兔角膜缘干细胞可在羊膜上继续增生、分化为多层角膜上皮细胞;角膜缘干细胞移植术后兔角膜缘轻度充血、角膜上皮完整、基质细胞浸润减轻、新生血管减少或消失。结论 应用角膜缘干细胞羊膜移植术可恢复其角膜上皮结构的完整性,减少角膜新生血管的形成,维持角膜缘的细胞屏障功能。     

自体角膜缘干细胞移植治疗翼状胬肉

目的探讨自体角膜缘干细胞移植重建角膜缘干细胞治疗翼状胬肉的临床疗效。方法近6年来1032例（1285眼）翼状胬肉行自体角膜缘干细胞移植术,重建角膜缘干细胞,术后进行严格用药并定期复诊,术后随访6个月～5年。结果1285眼术后胬肉复发46眼,占3．58％。结论自体角膜缘干细胞移植重建具有功能活性的角膜缘干细胞是治疗翼状胬肉较为好的手术方法。     

单眼双侧翼状胬肉联合手术临床疗效观察

目的:观察患眼带自体角膜缘干细胞的结膜瓣移植加健眼带自体角膜缘干细胞的结膜瓣移植治疗单眼双侧胬肉的临床疗效.方法:对24例24眼患者单眼双侧胬肉行翼状胬肉切除及自体角膜缘干细胞移植术,鼻侧结膜瓣自患眼上方取,颞侧行结膜瓣自健眼取,随访7~16mo,观察临床疗效.结果:所有患者伤口愈合良好,1例复发,复发率为4%.结论:患眼带自体角膜缘干细胞的结膜瓣移植加健眼带自体角膜缘干细胞的结膜瓣移植治疗单眼双侧胬肉临床疗效好,复发率低,为解决单眼双侧翼状胬肉复发率较高的问题提供一种较好治疗方法.     

Limbal Stem Cell Transplantation and Complications

ABSTRACT

Corneal epithelial stem cells are adult somatic stem cells located at the limbus and represent the ultimate source of transparent corneal epithelium. When these limbal stem cells become dysfunctional or deficient, limbal stem cell deficiency (LSCD) develops. LSCD is a major cause of corneal scarring and is particularly prevalent in chemical and thermal burns of the ocular surface. LSCD leads to conjunctivalization of the corneal surface, neovascularization, recurrent or persistent epithelial defects, ocular surface inflammation, and scarring that, in turn, lead to decreased vision, pain, and impaired quality of life. Several techniques have been reported for limbal stem cell transplantation (LSCT). We introduce the surgical techniques, examine the success rate, and discuss the postoperative complications of conjunctival limbal autograft (CLAU), cultivated limbal stem cell transplantation (CLET), simple limbal epithelial transplantation (SLET), and limbal allograft, including keratolimbal allografts (KLAL) and living-related conjunctival allograft (LR-CLAL).     

培养角膜缘干细胞羊膜移植治疗碱烧伤动物的实验研究

目的 观察培养生长于羊膜的角膜缘干细胞移植的治疗角膜缘碱烧伤伤的效果。方法 将兔角膜缘干细胞在的代培养后接种于羊膜,对新西兰大白兔角膜缘碱烧伤动物模型行角膜缘干细胞羊膜移植术,并对治疗后的角膜进行临床及病理学检查。结果 体外培养的兔角膜缘士细胞可在羊膜上继续增殖、分化为密集的角膜上皮细胞层;角膜缘干细胞移植术后兔角膜缘轻度充血、角膜上皮完整基质细胞浸润减轻、新生血管减少。组织病理学染色证实,角膜缘     

Oberfl?chenrekonstruktion bei Limbusstammzellinsuffizienz

Various ocular surface diseases are caused by loss of corneal epithelial stem cells or dysfunction of the limbal stem cell niche. Besides conventional transplantation of autologous or allogenic limbal tissue, recent advances in tissue engineering have led to the development of new culture and expansion techniques of human limbal stem and progenitor cells (LSPC) as a new strategy to successfully treat limbal stem cell deficiency (LSCD). From a small autologous limbal biopsy with a limited amount of LSPC an epithelium ready for transplantation is achieved. Autologous grafting of cultured limbal epithelium led in most of the treated cases to a successful reconstruction of the corneal surface. Alternative methods which have recently been introduced to treat LSCD use other stem cell sources including the transplantation of oral mucosal epithelium. In this article the challenges and controversies associated with these stem cell culture techniques for ocular surface reconstruction are reviewed.     

Transforming ocular surface stem cell research into successful clinical practice

It has only been a quarter of a century since the discovery of adult stem cells at the human corneo-scleral limbus. These limbal stem cells are responsible for generating a constant and unending supply of corneal epithelial cells throughout life, thus maintaining a stable and uniformly refractive corneal surface. Establishing this hitherto unknown association between ocular surface disease and limbal dysfunction helped usher in therapeutic approaches that successfully addressed blinding conditions such as ocular burns, which were previously considered incurable. Subsequent advances in ocular surface biology through basic science research have translated into innovations that have made the surgical technique of limbal stem cell transplantation simpler and more predictable. This review recapitulates the basic biology of the limbus and the rationale and principles of limbal stem cell transplantation in ocular surface disease. An evidence-based algorithm is presented, which is tailored to clinical considerations such as laterality of affliction, severity of limbal damage and concurrent need for other procedures. Additionally, novel findings in the form of factors influencing the survival and function of limbal stem cells after transplantation and the possibility of substituting limbal cells with epithelial stem cells of other lineages is also discussed. Finally this review focuses on the future directions in which both basic science and clinical research in this field is headed.     

Limbus transplantation for reconstruction of the ocular surface

Proliferation of the corneal epithelium originates in undifferentiated, long-lived stem cells that are located in the basal limbal epithelium. Stem cells are important for corneal epithelial regeneration and wound healing. Depletion of stem cells due to accidents as well as malfunctions of stem cells due to inborn or inflammatory diseases result in limbal stem cell deficiency. Limbal deficiency is characterized by conjunctivalization of the cornea with vascularization and opacification. Partial limbal deficiency can be treated by removing ingrown conjunctival epithelium thus allowing normal limbal epithelium to repopulate the cornea. Unilateral limbus-derived stem cell disease requires either limbal autograft transplantation from the healthy partner eye or kerato-limbal allograft transplantation. Several modifications of the latter technique have been performed including large kerato-limbal lamellar grafts and central penetrating kerato-limbal allografts. All homologous procedures render a very high risk of immunological reactions that require long term systemic immunosuppression. The use of amniotic membrane, better pharmacological drugs for immunosuppression and improvements in the HLA-matching of limbal allografts as well as ex vivo expansion of corneal stem cells should allow for better reconstruction of the ocular surface in limbal deficiency.