A heart disease that seriously threatens human health. According to statistics, at least 2.5 million new myocardial infarctions in my country each year, and the number of people who die from myocardial infarction and its complications each year has exceeded 1 million.

Myocardial infarction is a heart disease that seriously threatens human health. According to statistics, at least 2.5 million new myocardial infarctions in my country each year, and the number of people who die from myocardial infarction and its complications each year has exceeded 1 million. Although timely drug treatment, percutaneous coronary intervention, coronary artery bypass transplantation and other treatment methods can save the lives of some patients with myocardial infarction, there is still a lack of effective treatment methods for severe old myocardial injury.

htmlOn September 11, JAMA Network Open, a sub-public of the Journal of the American Medical Association, published online the important research results of the cooperation between Dai Jianwu's regenerative medicine team of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences and Professor Wang Dongjin's team of Nanjing Gulou Hospital. As the first clinical study in the world to treat ischemic heart disease with injectable stent material combined with stem cell transplantation, it proved for the first time the clinical safety and feasibility of injectable stent material combined with stem cells for the treatment of heart disease, and showed good application prospects, laying the foundation for subsequent large-sample clinical trials.

The first international clinical study of injectable collagen stent material combined with stem cell transplantation for the treatment of ischemic heart disease, jointly conducted by Dai Jianwu's regenerative medicine team and Professor Wang Dongjin's team, recruiting patients with old myocardial infarction since March 2016. Through one-year follow-up of 44 enrolled subjects, the results showed that cell and material transplantation are safe. Collagen material combined with stem cell transplantation can significantly reduce the patient's heart infarction volume after one year, and the patient's quality of life and heart rating improved. The effect is particularly obvious for patients with severe preoperative conditions (cardiac ejaculation fraction is less than 40%).

stem cells have self-renewal and differentiation potential as well as strong nutrition and secretion functions. Stem cell transplantation is a hot topic in the field of myocardial regeneration. At present, a large number of clinical studies have been carried out in the treatment of myocardial infarction, and there are hundreds of related studies registered on the Clinical Trail website, but its therapeutic effect is still controversial. Some studies have shown that stem cells are prone to spread after transplantation, and it is difficult to colonize and survive in the damaged site, affecting the treatment effect. How to promote stem cell colonization in myocardial injury sites is a key issue that stem cell therapy needs to be solved.

Dai Jianwu's regenerative medicine research team has been engaged in the research of regenerative medicine functional biomaterials for many years. After years of research, it has successfully developed a collagen scaffold with good biocompatibility that can be used for intramuscular injection, which can provide cells with stable extracellular matrix support. After injection into damaged myocardial tissue, it can effectively limit the spread of cells from the damaged site, helping to reshape myocardial regeneration and repair the microenvironment. The material has completed product standardization research and has obtained product technical requirements certification, biosafety testing, immune evaluation, virus inactivation testing and other reports from authoritative institutions such as the China Food and Drug Inspection Institute, and has reached the quality standards of clinical implantable medical devices.

can inject collagen material. A is the electron microscope picture of the material, B is the electron microscope picture after the material is mixed with mesenchymal stem cells, and C is the photo of the material being extruded from the 27G needle.

In the past 10 years, Dai Jianwu's team and Wang Dongjin's team have cooperated to carry out preclinical large animal experiments to test the safety and effectiveness of material and cell transplantation. In the old pig myocardial infarction model with coronary ligation, injectable collagen materials with normal saline, umbilical cord mesenchymal stem cells and mixed umbilical cord mesenchymal stem cells were injected respectively. Blood biochemical analysis, cardiac ultrasound and cardiac nuclear magnetic analysis, and histopathological examination were performed at multiple time points within one year after injection. It was found that the material and stem cell transplantation were good. Compared with the control group, material combined with stem cell transplantation can promote angiogenesis of myocardial infarction tissue, inhibit the expansion of pig heart infarction volume, and promote cardiac function recovery.

Based on the clear safety and effectiveness evaluation of animal experiments, the team further formulated a clinical trial plan, completed ethical review and international clinical research registration, and carried out randomized controlled clinical research research on injectable collagen materials combined with umbilical cord mesenchymal stem cells in the treatment of ischemic heart disease with funding from the strategic pilot science and technology special project of "Stein Cells and Regenerative Medicine Research" of the Chinese Academy of Sciences and the key deployment project "Tissue Organ Regeneration and Injury Repair".

The basic enrollment criteria for this clinical study are patients with old myocardial infarction who need bypass surgery with cardiac function less than 45%. After more than three years of hard work, a total of 50 patients were enrolled in the study and 44 patients completed one-year follow-up. The results showed that cell and material transplantation were safe, and there was no obvious difference between the control group in terms of incidence, biochemical indicators, immune indicators, etc. Compared with the control group, collagen material combined with stem cell transplantation can significantly reduce the patient's heart infarction volume after one year, and the patient's quality of life and heart rating improved. The effect is particularly obvious for patients with preoperative cardiac ejaculation fractions less than 40%: one year after the combined injection of bypass and stem cells and collagen materials, the average cardiac ejaculation fraction increased by 9.35%, while the control group increased by 6.59% (bypass surgery combined with stem cell transplantation group) and 3.62% (bypass surgery alone).

Representative nuclear magnetic bull eye diagram of patients in combination with collagen material and mesenchymal stem cells. Figure A shows the heart transmural index, and the degree of infarction gradually increases from blue to red. Picture B red shows more than 50% of tissues in infarcts.