Development of biological and synthetic substrates for the ex-vivo expansion of conjunctival epithelium for ocular surface reconstruction

开发用于结膜上皮离体扩张以进行眼表重建的生物和合成基质

• 批准号: MR/K023357/1
• 负责人: Shivani Kasbekar
• 金额: $ 16.18万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FK023357%2F1
• 关键词: Development; biological; synthetic; substrates; ex

Background The conjunctiva is a thin membrane that covers and protects the surface of the eye. It lines the inner surfaces of the upper and lower eyelids creating anatomical spaces between the eyelids and eyeball known as conjunctival fornices. The conjunctiva may become irreversibly damaged and the fornices obliterated by scarring following injuries such as chemical burns, severe infections or autoimmune disease. When severe, this prevents eyelid closure, restricts movement and causes lid deformity leading to painful blindness when the cornea (optically clear structure on the eye's surface) becomes opaque due to progressive abrasion and scarring. Such patients comprise up to ten percent of patients attending specialist ocular surface clinics. So far techniques to replace conjunctiva have failed as a result of recurrent scarring or because the graft has been insufficient in size. These patients invariably suffer visual loss due to corneal disease which cannot be addressed with clear corneal grafts unless the ocular surface is restored first. I will develop a novel biological and synthetic material on which the patient's own conjunctival cells will be cultivated to create larger grafts for transplantation. Conjunctiva will be retrieved from a cadaver and the cellular (living components) removed leaving behind a 'biological scaffold'. Eventually this research will lead to a patient's own cells being seeded on the developed substrate and the resulting graft transplanted into the same individuals so that an immune reaction should not occur. Examples of biological scaffolds successfully transplanted in humans include skin, heart valves and trachea. The synthetic substrate will be developed on a well tolerated biomaterial (ePTFE), commonly known as 'Gore-Tex', also used in medical devices such as grafts for blood vessel repair. This has been previously shown to support fornix reconstruction but growth of conjunctiva on its surface would be novel. I plan to render the surface conducive to cell growth by incorporating chemical groups and proteins on the ePTFE surface. My preliminary work has shown conjunctival growth on gas plasma treated ePTFE but further development is required to achieve optimal results. Aim: To develop decellularised human conjunctiva and ePTFE with novel surface chemistry to enable conjunctival expansion for future use as grafts.How research will be conducted Human conjunctival tissue will be obtained from deceased patients at the Royal Liverpool University Hospital and the research carried out in laboratories in the University of Liverpool. A novel protocol for the decellularisation of conjunctiva will be developed through collaboration with NHS Blood and Transplant, Liverpool. The ePTFE will undergo chemical modification by a process that changes surface chemistry (gas plasma treatment) and binding of proteins. Once both substrates have been developed, cadaveric conjunctival biopsies will be cultured on the two novel surfaces leading to the production of two conjunctival constructs. The physical and biological properties of the engineered constructs will be tested and compared to natural human conjunctiva.Expected outcomes This research will benefit patients who require conjunctival replacement for reasons including glaucoma surgery, excision of conjunctival growths and fornix reconstruction. The greatest impact of this research will be in patients with severe ocular surface disease ranging from autoimmune conditions such as mucous membrane pemphigoid to those with chemical burns. These novel grafts will enable ophthalmologists to develop new surgical strategies to reconstruct the surface of the eye. This will profoundly reduce pain and improve visual outcomes for patients with severe conjunctival disease. The novel materials developed through this fellowship could also lead to cell replacement therapies to treat other incurable eye diseases in the future.

背景结膜是覆盖和保护眼睛表面的一层薄膜。它在上、下眼睑的内表面形成线条，在眼皮和眼球之间形成解剖空间，称为结膜穹隆。在化学烧伤、严重感染或自身免疫性疾病等损伤后，结膜可能会受到不可逆转的损害，穹隆可能会因疤痕而消失。严重时，这会阻止眼皮闭合，限制运动，当角膜(眼睛表面的光学透明结构)因逐渐磨损和疤痕而变得不透明时，会导致眼睑畸形，导致疼痛失明。这类患者占到眼表专科诊所就诊患者的10%。到目前为止，由于复发的疤痕形成或因为移植结膜的大小不足，替换结膜的技术都失败了。这些患者总是由于角膜疾病而导致视力丧失，除非首先恢复眼表，否则无法通过透明的角膜移植来解决。我将开发一种新的生物和合成材料，在这种材料上培养患者自己的结膜细胞，以创建更大的移植结膜。结膜将从身体上取出，细胞(活成分)将被移除，留下一个“生物支架”。最终，这项研究将导致患者自己的细胞被种植在开发的底物上，并将由此产生的移植物移植到相同的个体中，这样就不会发生免疫反应。成功移植到人体的生物支架包括皮肤、心脏瓣膜和气管。这种合成基材将在一种耐受性良好的生物材料(EPTFE)上开发，这种材料通常被称为“Gore-Tex”，也用于医疗设备，如血管修复的移植物。这已经被证明支持穹隆重建，但结膜表面的生长将是新奇的。我计划通过在ePTFE表面加入化学基团和蛋白质来使表面有利于细胞生长。我的初步工作表明，气体等离子体处理的ePTFE结膜生长，但需要进一步的开发才能达到最佳效果。目的：开发具有新型表面化学的脱细胞人类结膜和ePTFE，以使结膜扩张，以便将来用作移植物。将如何进行研究将从皇家利物浦大学医院的已故患者身上获得人类结膜组织，并在利物浦大学的实验室进行研究。通过与利物浦NHS血液和移植中心的合作，将开发一种新的结膜脱细胞方案。EPTFE将通过改变表面化学(气体等离子体处理)和蛋白质结合的过程进行化学修饰。一旦两种基质都显影，身体结膜活检将被培养在两种新的表面上，从而产生两种结膜结构。工程结构的物理和生物学特性将被测试，并与自然人类结膜进行比较。预期结果这项研究将使因青光眼手术、结膜生长切除和穹隆重建等原因而需要结膜置换的患者受益。这项研究将对患有严重眼表疾病的患者产生最大影响，患者范围从自身免疫性疾病，如粘膜类天疱疮到化学烧伤。这些新的移植物将使眼科医生能够开发新的手术策略来重建眼睛表面。这将大大减轻疼痛，改善严重结膜疾病患者的视觉结果。通过这一奖学金开发的新材料还可能导致细胞替代疗法，在未来治疗其他无法治愈的眼病。