A tissue engineered corneal epithelium replacement for animal testing using human stem cells

人类干细胞在治疗严重疾病或损伤中的应用目前正处于快速发展阶段。这项深入的研究已经产生了新的治疗失明的方法。英国和日本的科学家们现在正在培养从捐赠者角膜（眼睛前部的透明组织）中提取的成人干细胞，以创造新的功能组织。这些再生的组织然后被移植到患病或受伤的眼睛的表面上，导致患者视力的恢复。人类干细胞的使用不必限于临床治疗用途，即旨在重建人类的视力，它们也可以用于显著减少医学研究中使用的动物数量。目前，每年需要数千只兔子来测试新药和化妆品的潜在毒性。50多年来，用于测试兔子眼睛的方法几乎没有变化。现在，通过利用最近在治疗性干细胞研究中取得的科学进步来制造基于人类组织的复制品，我们的目标是开发一种基于人类干细胞的非动物替代药物和纳米材料测试。这样做的优点主要是可以在不伤害任何动物的情况下评估新化学品/材料的效果，并且由于复制组织是由人类干细胞形成的，因此结果也更具代表性。此外，我们的非动物模型可以评估水不溶性材料，如纳米材料，这是动物模型做得不好的。为了开发一种基于人类干细胞的非动物替代药物测试的方法，我们将在一个塑料盘中重现人眼的表面。使用从成人角膜供体组织中分离的成人干细胞，并建立在成功用于角膜干细胞移植的技术基础上，我们将确定一种合适的方案和基质，该方案和基质能够在体外支持功能性角膜上皮的形成并易于来源。新开发的基于人类干细胞的非动物替代药物测试的适用性将通过对模型对已知有毒和无毒试剂的反应进行严格测试来确定。将通过显微镜检查和已建立的毒性试验稳健评估模型对毒性试验的反应。

The use of human stem cells in the treatment of serious disease or injury is currently undergoing a phase of rapid development. This intensive research has already produced new treatments for blindness. UK and Japanese scientists are now growing adult stem cells taken from donor corneas (the transparent tissue at the front of the eye) on specialised membranes to create new functional tissue. These regenerated tissues are then transplanted onto the surface of diseased or injured eyes leading to a restoration of the patients' sight. The use of human stem cells need not be limited to clinical theraputic use i.e. aimed at re-establishing vision in humans, they can aslo be used to significantly reduce the number of animals used in medical research. Presently, thousands of rabbits are needed every year to test for the toxic potential of new drugs and cosmetics. The method used in testing on rabbits eyes has changed little over 50 years. Now, by employing the scientific advancements recently made in therapeutic stem cell research to the manufacture of a human tissue based replica in culture, we aim to develop a human stem cell based non-animal alternative to drug and nanomaterial testing. The advantages of this are primarily that the effect of new chemicals/materials can be assessed without any animals being harmed and since the replica tissue is formed from human stem cells the results are also more representative. Furthermore, our non-animal model can assess water insoluble materials such as nanomaterials, something the animal models can not do well. To develop a human stem cell based non-animal alternative to drug testing we will essentially recreate the surface of the human eye in a plastic dish. Using adult stem cells isolated from adult corneal donor tissue and building upon the techniques sucessfully employed for corneal stem cell transplantation, we will identify a suitable protocol and substrate capable of both supporting the formation of a functional corneal epithelium in vitro and being easily sourced. The suitability of the newly developed human stem cell based non-animal alternative to drug testing will be established by vigorous testing of the model's response to known toxic and non-toxic agents. The model's response to toxicity testing will be robustly assessed by microscopy and established toxicity assays.