Stem cells can regulate immunity, promote peripheral tissue regeneration, and cell differentiation, and participate in wound repair in the human body. Taiwan has initiated special regulations for cell therapy since 2018, allowing autologous transplantation of stem cells in the treatment of various diseases, including chronic wounds, degenerative arthritis, ischemic stroke, or spinal cord injuries. Stem cell therapy is still in its infancy, and there are still many issues to be resolved. For example, after stem cells are injected into the wound, microenvironmental factors such as low oxygen, high inflammation, and high free radicals in the wound are often unfavorable for the survival of stem cells.

In addition, stem cells after transplantation also face the problem of loss, which seriously affects the effect of stem cell therapy. To address the above issues, injectable cell scaffold materials may be utilized to enhance cell efficacy by improving the retention and activity of stem cells. Ordinary injectable scaffold materials can be mixed with stem cells. However, the crosslinking mechanisms such as temperature, pH, or enzymes may delay gelation, making it difficult to precisely control the formation of a cell-laden hydrogel. We currently develop a novel self-healing hydrogel material shGEL-X, which is applied to improve the efficiency of stem cell transplantation. This material is mainly composed of two natural polymers, GEL and X. After the GEL polymer aqueous solution is uniformly mixed with stem cells, then X polymer is added to form stem cell-laden shGEL through the reversible bond between GEL and X polymer. The self-healing property of shGEL-X allows it to re-form a hydrogel structure after injection, overcoming the delay in the gelation time of traditional injectable materials, can precisely control the injection position of the hydrogel, and enhance the therapeutic effect of stem cells.

The related technology has been affirmed by the 2020 National Innovation Award. This project will further introduce the microfluidic technology platform to achieve stable manufacturing of injectable steel cell-laden microgels and will explore the application of shGEL-X as a gel material combined with genetically modified stem cells in tissue engineering and regeneration.