The performance horse market may decide. Which is more clinically effective? Which is more economic, easier to extract, yields greater quanties of effective cells? The answer, perhaps only that there is no difference, will impact at least one of our sector companies, perhaps more than one.
"It's very exciting (field) and incredibly promising," says researcher Lisa Fortier of Cornell University's College of Veterinary Medicine. "Not only for horses. Researchers are exploring the potential of stem cells in human orthopedics also, and if the approach works in the equine world, it will probably work in the human one. Two-legged patients have only a fraction of the joint stress. "A horse is essentially walking around on your middle finger," Fortier says.
The performance horse market is being addressed in Europe by VetCell Bioscience Limited, a company formed in partnership with the Royal Veterinary College and the Institute for Orthopaedic and Musculoskeletal Science to develop the veterinary use of stem cell technologies.
VetCell uses bone marrow derived stem cells in the treatment of tendon and ligament injury in horses. A veterinary surgeon removes a bone marrow sample from the sternum of an injured horse under standing sedation and local anesthetic. The stem cells are then extracted and multiplied at VetCell’s laboratories before being returned to the veterinary surgeon for implantation directly into the core of the lesion.
VetStem, another private company, this one located in San Diego, is addressing the United States performance horse market. VetStem, which is very good at self promotion, uses adipose (fat) derived stem cells to do exactly the same thing VetCell does in Europe, claiming 3,000 horses treated since the company's inception. As with Cytori Therapeutics, a sector company totally committed to adipose derived stem cells, but which is not involved on the veterinary side, VetStem claims that adipose derived stem cells have two major advantages over bone morrow derived cells. The first is ease of extraction (probably true); the second is purportedly in the concentration of stem cells per unit extracted (this claim is highly questionable).
Here's why that claim is questionable (The following is an excerpt from a paper written by Lucy Richardson, Department of Veterinary Clinical Sciences, The Royal Veterinary College):
Mesenchymal stem cells (MSCs) can be obtained from bone marrow aspirate, usually taken from either the iliac crest or sternum (Gronthos et al, 1998) or from adipose tissue (Gimble and Guilak, 2003). De Ugarte et al, (2003) found that there was no significant difference in adherent cell yield (italics and underlining mine), growth kinetics, cell senescence, differentiation capacity or gene transduction efficiency between bone marrow derived MSCs and those derived from adipose tissue. Bone marrow can be separated into its constituent parts by density centrifugation, usually over Ficoll at 400g for 30 minutes (Gronthos et al, 1998, Smith et al, 2003) or 500g for 25 minutes (Rickard et al, 1996). The buffy layer containing the MSCs can then be separated and stored. The MSCs in adipose tissue can be separated by first mincing the tissue and then digesting it with type I collagenase at 37ºC, the constituents are then separated by differential centrifugation at 1200g for 5 minutes (Gimble and Guilak, 2003 and De Ugarte et al, 2003). Because of their high lipid content, the mature adipocytes will reside in the supernatant, while the pellet will contain the A-MSCs (Gimble and Guilak, 2003).
This paragraph (the entire paper is referenced below), suggests there is little difference in the end result between the two approaches, bone marrow vs. adipose (fat). That said, Colorado State University has done some studies from which they drew the suggestion that bone marrow derived stem cells may reduce inflamation relative to adipose derived cells. There have not been a lot of studies. Much work is left to be done. While recent studies of stem cell therapies have produced encouraging results, Fortier also points out that "there is zero peer-reviewed published evidence that this actually works."
In February 2008, Thermogenesis Corp., one of our sector companies, announced that its wholly-owned subsidiary, Vantus, Inc. (formed at basically the same time), has signed a formal agreement with the UC Davis School of Veterinary Medicine's Center for Equine Health and its Stem Cell Regenerative Medicine Group to conduct joint research and development of methods to enhance the collecting, processing and storing of stem cells from equine cord blood, bone marrow and placental tissue. These cells will be used in the development of therapeutics for the prevention and treatment of orthopedic injuries, such as tendon and ligament injuries, in performance horses. In other words, Thermogenesis, through its subsidiary, Vantus Inc., is going head to head with the two private companies that have been in this field. And Thermogenesis is all about bone marrow derived stem cells, claiming that the equine orthopedic market alone is in excess of one billion dollars.
Both of the bone marrow derived stem cell companies, Vantus and VetCell, are also in the cord blood collection and storage business for performance horses. VetStem is not.
In 1961 researchers showed that stem cells could develop into tendon cells in the lab, and by the end of the 1990’s the regeneration of new tendon-like tissue had been seen in small animals. The early part of this century saw the formation of both VetStem and VetCell.
Adapted from "The Use of Mesenchymal Stem Cells in the Treatment of Equine Tendon Injuries" by Lucy Richardson, Royal Veterinary College, and other sources.