Despite the high hopes surrounding stem cells' potential to form replacement tissue for medical use, biologists are still struggling in the lab to get these finicky cells to transform into the needed tissues. Now Cartilix, a startup in San Carlos, CA, is offering a technology that might help: polymer materials that direct the growth and development of stem cells.

The startup is working on polymer gels that would be implanted into the joints of arthritic patients and serve as scaffolds upon which the patients' own bone marrow stem cells would form new cartilage. The stem cells would come from the blood that naturally seeps into the joint area during the implantation procedure; after new tissue forms, the polymer would biodegrade. The hope is that this treatment will help patients "get their own cartilage back" and avoid joint replacement surgery, says Frank Huerta, Cartilix's CEO.