Stem cell technology, also known as regenerative medicine, new, normal or even younger cells, tissues or organs are bred in vitro by separating stem cells, in vitro culture, directed induction, and even genetic modification, and ultimately the treatment of clinical diseases is achieved by transplantation of cells, tissues or organs. The application of stem cells to treat diseases is no longer just an idea. Although the research time of stem cells is limited, it has begun to enter the clinical trial stage with its treatment of diseases.
Recently, the New England Journal of Medicine published a study achieved by Chinese scholars which is the first time in the world to use gene editing methods to inactivate CCR5 gene in human hematopoietic stem cells and transplant the edited stem cells into HIV (HIV) infection combined with acute lymphoblastic leukemia.
Gene-edited hematopoietic stem cells can survive and multiply in patients, becoming the key to curing AIDS. The researchers claim this improvement proves that genetically engineered hematopoietic stem cells are safe in the human body and can survive. The research team will continue to improve the efficiency of gene editing and adjust the treatment plan to achieve the goal of treatment.
The editing efficiency and off-target effects of CRISPR gene editing technology have always hindered its clinical application. In order to meet the clinical requirements, the research team based on the establishment of the experimental animal verification technology system, explore a variety of conditions to establish a genetically edited hematopoietic stem cell pretreatment culture method, without destroying its dryness, stability state, survivability, etc. The team tried eight transfection methods that introduced “scissors” and explored ways to improve editing efficiency and reduce off-target efficiency by shortening editing time and introducing paired guide RNA strategies.
In recent years, gene editing technology has been continuously developed, and it is believed that a safe and more efficient gene editing technology system will be developed. Meanwhile, the optimization of existing methods will also improve efficiency in many ways. In the future, when genetically edited hematopoietic stem cells are able to produce enough T cells with mutations to fight HIV, a lasting effect may be achieved with one treatment.
As for stem cells, they can be applied to the culture of human tissues and organs in animals. The significance of this work is similar to that of the above-mentioned in vitro culture. The main technical principle is to inject human stem cells by genetically engineered animal embryos in order to obtain the corresponding organ tissues derived from human stem cells. Technically, complex in vitro stem cell culture, differentiation induction and tissue formation conditions can be avoided. But it also faces many challenges, such as how to improve the integration efficiency of human stem cells in animals.
Another important application of stem cells is the dedifferentiation and re-differentiation of patient tissue cells, which can be differentiated and re-differentiated by simple genetic manipulation, which is a revolutionary leap in theoretical research and clinical application of stem cells. In theory, the acquisition of dedifferentiated stem cells and in vitro culture can help to understand the nature of pluripotency and cell differentiation, and the degenerative stem cells associated with specific diseases can be used as an in vitro model system to study the mechanism of the corresponding diseases.
Stem cell transplantation or stem cell therapy is currently the most widely known method of stem cell therapy. Conceptually, it is simple because stem cells are pluripotent and differentiated, and injecting stem cells into specific tissues can repair diseased or physically damaged tissues. The American Clinical Trial Center has learned that clinical research on stem cells has been applied to hundreds of diseases in humans worldwide, and has made gratifying research progress. For example, scientists successfully applied stem cells to treat myocardial infarction, used mesenchymal stem cells to treat hematopoietic dysfunction and Parkinson’s disease, spinal cord injury, cirrhosis, osteoarthritis and so on. These clinical applications have made remarkable achievements. Regenerative medical researchers believe that the clinical application of stem cells and their derivatives and tissues is one of the greatest scientific achievements of human beings in the 21st century. It will definitely produce a new kind of treatment technology, which has set off a new round of medical technology revolution in human history.
In view of the special status of stem cells in the process of life development, scientists expect to explore new treatment technologies from stem cell research. The clinical practice of stem cell technology represents a major direction of future medical development, and it also carries the expectations of human beings to overcome incurable diseases.