Editor's note: corneal blindness is the second major blindness after cataract. At present, there are about 4 million corneal blindness in China, and more than 100000 cases are added every year. Corneal transplantation is the most important means to restore eyesight in patients with corneal blindness. However, due to various factors, there is a great lack of corneal sources in eye banks all over China, which limits the large-scale development of corneal transplantation. The emergence of corneal regeneration therapy may solve this problem and create a new era of corneal disease treatment. Recently, Professor Du Yiqin and his team published a review article - regenerative therapy for the cornea in the journal progress in retinal and eye research, reporting the current new research progress on stem cell induction promoting corneal repair. Professor Hong Jing of the Third Hospital of Peking University has been committed to the relevant research in the field of corneal transplantation and corneal regeneration for many years. He took the lead in carrying out corneal endothelial transplantation in China and popularized the operation technology, bringing light and hope to many patients with corneal blindness. International ophthalmology news specially invited Professor Hong to share his understanding of the literature reports on corneal regeneration therapy and explain the significance and Prospect of corneal regeneration therapy.
New direction of international research in the field of cornea: the progress of corneal regeneration therapy is gratifying, which will usher in a new era of corneal disease treatment
Corneal disease is a serious blinding eye disease. Although the current treatment methods for corneal diseases have made progress, they still promote corneal healing in the form of scarring, which will lead to the loss of corneal transparency, vision loss and even vision loss. Corneal transplantation is the only way to restore blindness and vision. Due to the lack of donor materials and the limitation of complications after corneal transplantation, corneal transplantation has not been widely carried out. Many patients with corneal diseases can not be effectively treated and are in a state of blindness.
In other medical fields, stem cell transplantation or tissue damage repair has made some progress. Due to the particularity of cornea - no blood vessels, we hope to maintain the transparent state and function of cornea when promoting corneal regeneration. Regenerative medicine will be an important development direction in the field of cornea. It can restore the original level of cornea through corneal self repair (or with the help of external forces, such as drugs or other methods), and cure the disease through the regenerative function of cornea. The application of regenerative medicine can not only effectively control diseases, but also maintain the transparency and refractive state of cornea. It has great potential in the treatment of corneal diseases.
Recently, Professor Du Yiqin and his team published a comprehensive article - regenerative therapy for the cornea in the journal progress in retinal and eye research, which comprehensively combed some research progress at home and abroad on stem cell induction and corneal repair. Professor Hong highly recognized the content of this article. Professor Hong believes that this article clearly describes the current progress of biological cornea from different levels and overall structure: stem cell induced regeneration and promoting tissue repair, including transplantation, have been carried out for more than 20 years, and great progress has been made from cell selection to tissue structure. The article mainly introduces from two aspects:
One is the selection of seed cells. Seed cells are divided into adult stem cells and adult stem cells plus embryonic stem cells. As we all know, corneal tissue mainly comes from epithelial cells, stromal cells and endothelial cells. In recent years, studies have confirmed the existence of corneal epithelial stem cells and stromal stem cells in the cornea. Now people put forward a new idea, that is, endothelial stem cells also exist in the cornea. The existence of stem cells provides a source for cell regeneration. The corresponding tissues can be regenerated by activating stem cells, which is also an important direction for people to make breakthroughs in relevant research. If some patients are seriously injured and stem cells in cornea no longer exist, we can consider transplanting stem cells from other sources (such as bone marrow mesenchymal stem cells, adipose stem cells, IPS stem cells and embryonic stem cells), especially embryonic stem cells, which have the most complete functions and the strongest ability to induce potential differentiation.
The second is the choice of support. Compared with three-dimensional stents, Professor Du Yiqin recommends two-dimensional stents. Some cells have certain self secretory ability. By adding some secretory factors, the cells can secrete extracellular matrix as soon as possible, which is more favorable than the artificial scaffold.
In addition, the article mentioned that 3D bioprinting technology has been applied to clinic, and it is expected to be applied to the field of cornea as soon as possible.
The development of corneal regeneration therapy in China is booming: the transplanted synthetic biological corneal membrane has been successful in animal experiments!
In the past two years, Professor Hong and his team have focused on the tissue engineering of corneal endothelial cells. Professor Hong pointed out that endothelial cells play a very important role in the corneal tissue level. Once endothelial cells are lost, it will lead to corneal edema, loss of corneal transparency and even loss of vision. Professor Hong and his team took the lead in carrying out corneal endothelial transplantation in China. Due to the lack of donor materials, many patients were unable to carry out the operation. It is a great challenge for corneal endothelial transplantation that donor materials can not meet the clinical needs. Professor Hong and his team met the difficulties and synthesized biomaterials with the help of tissue structure and applied them in clinic. At present, the relevant animal experiments have been successful: the endothelial cells cultured in vitro are placed on the scaffold to construct the membrane of corneal endothelial cells, and then transplanted into animals. The results showed that the membrane maintained very good transparency after transplantation. Relevant articles were published on experience eye research. Professor Hong and his team are still carrying out relevant research, which is expected to achieve the treatment of corneal endothelial diseases with cell growth in the future.
Corneal transplantation treatment Trio: from a difficult start to an innovative break, corneal regeneration therapy will bring new treatment opportunities in the future
The history of corneal transplantation treatment is an epic of human pursuit of light:
Departure: the initial corneal transplantation was full-thickness corneal transplantation;
Breakthrough: with the development and progress of medical technology, the transition from full-thickness corneal transplantation to component transplantation, that is, which layer of cornea has lesions and which layer corresponds to the transplantation treatment;
Future: corneal transplantation may enter the era of stem cell transplantation in the future.
Professor Hong pointed out that the main three-layer structure of corneal tissue - epithelial cells, stromal cells and endothelial cells. Most of the extracellular matrix can construct the surrounding cell structure through synthesis or cell secretion promotion, while the cells themselves cannot be constructed and can only be transplanted. In the future, no matter which layer of cornea has lesions, as long as the stem cells at the corresponding layer are transplanted in and treated with the help of the patient's own cell framework. Even in the early stage of the disease, in the process of lesion development and not yet fully formed, stem cell transplantation can be carried out while treating the primary disease, so as to maintain the reconstruction of cell structure and better vision. Professor Hong said that for the treatment of corneal diseases, stem cell transplantation is the goal and direction of pursuit and development in the future. We expect stem cell transplantation to become a reality as soon as possible.