Stem Cells and Cartilage Repair; the Product we Need

In the latest edition of the ICRS (International Cartilage Repair Society) newsletter (winter 2012) there are no fewer than 21 papers on the use of mesenchymal stem cells for some aspect of cartilage repair. This level of interest mirrors the popularity of stem cells in the news, and the number of patients who are doing self-directed ‘research’ on the internet and have concluded that this is the way to go. As I have said  before in this blog, there remains a wide gulf  between fascinating lab studies and the clinical application of cell therapy. nevertheless, in a consumer market, this does not prevent people from using them.

Caveat Emptor, let the buyer beware, is not a phrase that occurs to all people who are shopping for medical treatments.  But it should. The average person is just not capable of assessing the validity of an experimental claim, most especially one tried only in animals.  But I fully understand how a glimmer of hope can lead to less than rational conclusions.

Let me describe the product we need: an injectable (not a surgical) therapy; a high safety profile;  of reasonable cost (less than $2000 would work); easy administration for the average doctor; targeted to the lesion, repeatable (if needed); widely available; moderate shelf life(say 2 weeks). In addition the cells should have along with them an appropriate scaffold replete with whatever growth factors are needed to regenerate tissue. And all of this needs to be in a single delivery system.

For example: a hand held ultrasound will some day show us the hole in the cartilage. the, under local anaesthesia, and in the doctors office, we direct a needle to the right spot and squirt in a self adhering jelly that contains all of the elements described above. It lands in the right place and starts to grow, and grows only cartilage, and stops growing when the hole is covered.

The cells to be used could be from the patient’s own bone marrow or they could be obtained from a tissue bank. The regulatory hurdles are more severe in the latter case, but that kind of scrutiny brings with it the type of convincing studies that are required to really prove a new technique is effective. So we might envision an autologous  (from the patient)product first, a pilot study, and then an allograft (from a tissue bank)  based product. Each of these would have to be predicated upon animal experiments.

This is not a far fetched concept, but we are not yet close.