Tianjin University scientists have invented a new technology pertinent to dimethyl sulfoxide (DMSO)-free cryopreservation of Chondrocytes based on the zwitterionic molecule and polymers as cryoprotectants (CPAs), which is the first of its kind in the world. The paper was published in Macromolecules.
This technology applies to cryopreservechondrocytes. The new CPAs are non-cytotoxic and present no side effects, which is expected to be a significant breakthrough in cell therapy. It will bring new hope for those who suffer from blood diseases and cancer.
Cell therapy works by culturing cells outside of the human body and then transplanting them into the patient, so that the injured tissues and cells can be repaired or replaced.
At cryogenic temperatures ( -80℃ or -196℃), the cell appears to be a suspended state because the cell metabolism totally stops. As a result, the cellular activity and functions are able to be preserved long term.
However, the ice crystals produced during the freezing process causes fatal cryoinjuries to the cells, which has challenged the technology. The main solution to this problem currently is to add organic solvents like dimethyl sulfoxide (DMSO) that possesses intrinsic toxicity, so that the recovered cells have to go through a complex procedure to remove DMSO before culturing or transplantation into patients.
On one hand, the DMSO-cryopreserved cells still have many side effects to patients even after the washing procedure. They may cause nausea, vomiting, bronchospasm, renal failure, heart block, among others. On the other hand, the clinical application in China relies on the import of such kind of product which is expensive.
Zwitterionic betaine was selected for intracellular protection, which made the cryopreservation of chondrocytes a success. A 90+% post-thaw survival efficiency has been achieved due to the application of zwitterionic betaine, bringing forth newcell cryopreservation technology. According to the results of the experiment, this know-how causes no severe damage to both the cell’s activity and function, which makes chondrocyte cryopreservation efficient, so that the recovered cells are expected to apply directly to clinical therapy.
Schematic diagram of technical principle of dimethyl sulfoxide (DMSO)-free cryopreservation of Chondrocytes
This achievement has been regarded as a national patent, and is currently applying for a PTC patent.
The research team was led by Tianjin University’s teachers Zhang Lei and Yang Jing.
“We are now testing other types of human somatic cells”, Yang said, “with thecell cryopreservation product developed by our team. This technology is totally noncytotoxic and is expected to replace imported products, which will greatly reduce the cost of scientific research and clinical practice. This is definitely good news to those who need cell therapy.”
By: Wu Jingjing
Editors: Harlan Haverback, Sun Xiaofang
