Japan'S Research And Development Of Artificial Blood: Preservation For One Year Without Blood Restriction, Clinical Application Still Exists

The use of artificial blood instead of some or all of the functions of blood to solve the shortage of blood products has become one of the difficult problems that people have been trying to overcome for a long time.

Not long ago, according to Japan's Asahi Shimbun, Japan's research team based on Japan's Defense Medical University announced that they had successfully developed an artificial blood that can save many lives. This artificial blood can be stored at normal temperature for more than 1 years without considering the different blood groups. At present, this artificial blood has been successfully tested on experimental rabbits.

But Zhou Jiaxi, a researcher at the Chinese Academy of Medical Sciences hematology Institute and the State Key Laboratory of Experimental Hematology at hematology hospital, pointed out that human blood is very complex and artificial blood is almost impossible. At present, artificial blood is studied in some components of artificial blood, and the more common ones are artificial red blood cells and platelets. The Japanese team developed artificial blood consisting mainly of artificial platelets and artificial red blood cells. They made tiny bags from a cell membrane called liposomes and filled them with hemostatic components and components that could transport oxygen.

"Artificial blood is not the restoration of the whole blood of human body, and it can not go in this direction in scientific research field. The mainstream research direction of artificial blood is still developing to a part of components that can transport oxygen, stop bleeding and assist blood. The artificial blood in this study can be simply interpreted as the physiological saline at the blood level. A researcher from a biopharmaceutical enterprise in Shenzhen told reporters on twenty-first Century economic report.

Artificial blood exploration

The most important function of blood is to transport oxygen. The carrier of oxygen is the hemoglobin in red blood cells. Therefore, the main idea of artificial blood is to find a carrier that can transport oxygen - red blood cells or hemoglobin. At present, there are two ways to achieve hematopoiesis: the first is the biosynthesis of red blood cells, white blood cells and platelets with complete biological functions; the other is the synthesis of the main functions of red blood cells or platelets.

But human hematopoiesis is different from the traditional understanding of human blood.

Artificial blood can be regarded as isotonic solution for gas exchange. It is exchange of oxygen, exchange of carbon dioxide and other gases of normal saline, in addition to this function, other functions are very difficult to achieve. A large number of similar artificial blood is transported, and the proteins, hormones and inorganic salts in the blood will be diluted. It can cause many problems, such as body temperature imbalance, hypokalemia, hypocalcemia and increased cardiac load.

"At this stage, artificial blood is still functional liquid, similar to the buffer used before, but it contains only small molecules of chemical properties, and there are not many bioactive substances, so the shelf life can be as long as one year. The real functional substances are very different in the human body, especially between individuals. There is a difference between quantity and quality. Real functional substances can be used in the metabolism of artificial blood resources. So it can be kept for a long time, just because there are not so many active ingredients (all kinds of catalyzed enzymes). At present, it is impossible to make enzymes into universal artificial blood, and can only make basic maintenance physiological similar buffers. If we want to simulate human blood, it is not the way of artificial blood production, but from stem cells. " The former researcher told reporters.

In the field of scientific research, artificial blood has two main directions, one is buffer, and the other two is the use of stem cells to study and produce functional cells.

Over the years, multinational scientists continue to explore in this field, using human hematopoietic stem cells, embryonic stem cells and induced pluripotent stem cell technology, large-scale cultivation of oxygen binding function of red blood cells, hoping to develop artificial blood that can replace normal red blood cells. From a number of previous studies, it is not difficult to use stem cell technology for large-scale cultivation of red blood cells with normal functions in vitro. However, there is a general lack of effective clinical trials to verify whether these cultured red blood cells can bind and release oxygen in vivo.

Application still space

At present, artificial blood has a certain distance from clinical application. Many hematopoietic studies have only stayed in animal testing stage, and have not really entered clinical trials. Japan, the fastest way, has just begun to apply for clinical trials. Security is the first big problem.

Secondly, it is the problem of mass production. Taking the platelets prepared by Japanese team of pluripotent stem cells as an example, the whole process takes 26 days, and it is difficult to solve the clinical emergency blood demand. Moreover, the clinical blood transfusion needs to achieve a certain amount of effectiveness. At present, the laboratory's ability to produce artificial blood is equivalent to the level of the family workshop, which is still far from the large-scale production of the factory.

Finally, the question of cost. At present, platelets prepared from pluripotent stem cells are much more expensive than donated platelets, and even cost tens of thousands of times higher than donated platelets. "If you lose a bag of platelets for 100 thousand yuan, then this artificial blood is meaningless." Zhou Jiaxi said.

According to the blood donation law of China, the blood of voluntary blood donation must be used in clinic, and it is not allowed to buy and sell blood. Therefore, the blood itself is priceless. The related expenses of clinical blood use are collected, stored, separated, tested, and transported by cold chain. As a special medicine, blood plays an important role in saving lives. Because the blood is not able to be replaced by artificial or other substances, the blood needed for medical treatment can only be donated.

For a long time, "blood bank emergency" has become the norm. "The current norm is that patients need blood, and they need blood donation from their families. Usually, hospitals have to take care of patients from all over the place, such as cardiothoracic surgery, Department of orthopedics, obstetrics and so on. The blood pressure is very heavy. Especially in winter and summer vacation, the peak period of blood is used. At this time, we have to arrange surgery according to the patient's condition. Compared with the seasonal characteristics of blood donation group, the hospital bed blood volume is increasing year by year, which is an important reason for the blood bank's emergency. A doctor from a third class hospital in East China told reporters on twenty-first Century economic report.