Cryogel sponge slowly releases stem cells to reverse arthritis in mice
With no real forms of treatment other than pain-relieving medications or a full joint replacement, osteoarthritis remains a difficult disorder to tackle, at great pain and discomfort to sufferers. Regenerating the degrading tissue in worn out joints through the use of stem cells is one promising possibility, and scientists in China have just demonstrated how a newly developed "cryogel" can be used to dramatically improve this technique's effectiveness, by reversing osteoarthritis in mice.
As it does in many areas of regenerative medicine, stem cell therapy holds great promise as a way of rebuilding the deteriorating tissue that characterizes osteoarthritis. But it isn't as simple as implanting the cells in the affected joints and letting them go to work. If the dosage is too high, it can incur side effects like redness, swelling and scar tissue, while if the dosage is too low, the therapy is limited in its effectiveness.
The authors of the new study, from Huazhong University of Science and Technology and Wuhan Union Hospital, believe they may have hit the sweet spot with the help of a new biocompatible scaffold. This material is a sponge-like "cryogel" that is made of gelatin and formed at subzero temperatures, and features a network of tiny, connected pores that allows it to be loaded up with small particles.
By seeding the cryogel scaffold with mesenchymal stem cells (MSCs) sourced from umbilical cord tissue and implanting them into the knees of osteoarthritic mice, the researchers were able to produce some promising results. They report that it provided the necessary support structure for the stem cells to remain in the area for a significantly longer period and be released slowly, working to dramatically relieve the pain arising from inflammation, and confer regenerative benefits that remained even after the cells had moved on.
"It takes about two weeks for half of the implanted cells to leave, but their regenerative effects stick around for longer," says corresponding author Wei Tong from the Department of Orthopedics of Union Hospital. "So it is possible that the therapeutic result comes indirectly, via the stem cells secreting epidermal growth factors, which stimulate cell proliferation and healing, rather than directly becoming newly formed cartilage in the joint."
According to the research team, this technique reduces the necessary dosage of stem cells by 90 percent, avoiding the risk of side effects but still reversing the arthritis in the knee joints of the rodents. The scientists hope to build on these promising results with further studies on non-human primates, with a view to one day offering clinical treatments that can reverse the effects of osteoarthritis in people.
The research was published in the Chemical Engineering Journal.