BEIJING -- Chinese researchers are studying the use of stem cell technology in the treatment of people critically ill with the novel coronavirus disease (COVID-19), according to the Science and Technology Daily.

Four COVID-19 patients who received stem cell treatment while in a serious condition have been discharged from hospital after recovery, and the clinical trial of the therapy will be further expanded, Vice Minister of Science and Technology Xu Nanping, was quoted by the paper as saying.

Stem cells can self-renew or multiply while maintaining the potential to develop into other types of cells. They can become cells of the blood, heart, lungs or other body parts.

Stem cells also have a strong secretory function, promoting the formation of new blood vessels, cell proliferation and differentiation and inhibiting inflammatory response, experts say.

Stem cell therapy has been used in the treatment of some infectious diseases and complications. For instance, it has been tried in treating H7N9 avian flu and showed good results.

According to the Ministry of Science and Technology, the Chinese Academy of Sciences has developed a new stem cell drug, CAStem, which has shown promising results in animal experiments. The research team has applied for urgent assessment by the National Medical Products Administration. Approvals by the ethics committee, and clinical observation and evaluation are in progress.

A research team from the fifth medical center of the Chinese PLA General Hospital is cooperating with hospitals and institutions in Wuhan, the epicenter of the epidemic, and North China's Tianjin municipality to conduct clinical research on the safety and effectiveness of mesenchymal stem cell therapy in treating COVID-19 patients.