Its been a busy week for me but a slow week on stem cell news. One piece of news that I thought interesting to mention was about the use of muscle stem cells obtained from a patient's thigh and implanted into his failing heart in the US. A company called Bioheart has been promoting the use of patient's own cultured muscle cells for re-implantation via angioplasty since its inception in 1999. They have been conducting clinical trials for their process- results expected in 2008- and have also developed related instruments for delivery (much like Cordis, which I blogged about in another entry).
The news piece related the story of a patient, Richard Howell, who had heart failure and underwent experimental heart surgery at The Cleveland Clinic (listed as one of Bioheart's clinical trial centers). The treating doctor, Dr. Stephen Ellis did not describe the procedure in any great detail but revealed that the patient received 18 separate injections of a total of 200 million cells. The article mentions a "surgery" that was performed and it is unclear to me as to whether the cells were delivered by angioplasty or by direct cardiac injection.
It does however, say that he underwent the surgery 6 weeks ago and is feeling much better than he has in six years, enough to be out on the beach when he could not leave his living room before.
Previous trials with stem cells obtained from thigh muscles had poor outcomes, enough to stall these trials in a number of countries including Singapore. The stem cells were cultured to form "myoblasts" which are muscle cells and injected into the heart. But little known to the scientists and doctors at the time, although the cells looked genuinely like cardiac muscle cells, they lacked one important and necessary factor- the timing of the heartbeat known as "twitch". Skeletal muscle (normal muscle) fibers exhibit "slow twitch" but cardiac muscle fibers have to have "fast twitch" in order to maintain the contractile action of the heart to pump blood around the body.
There were a few publications that came out strongly against this technique of using cultured thigh muscle cells- although the cells in culture did show the twitch rhythm of the heart- the results upon injection showed that the thigh muscle cells never really engrafted or express cardiac markers, and in fact the cells died after some time. The consequence of this poor clinical outcome was serious enough to warrant patients requiring a pacemaker and to take other measures for their worsening condition.
Ever since those publications in 2002-2003, support for this area of work has waned clinically but I'm sure scientifically, it has spurred the need for greater understanding of the expression markers necessary to show that at the minimum, these cells do no harm to the patient.
As for StemLife's work on the heart, we have taken a more conservative approach of using a mixed population of cells obtained from mobilized peripheral blood. Cell culture is neither cheap nor easy to prove that it works better than a mixed population of cells. For now, we'll be preparing the cells with our own in-house developed protocol, which has helped patients feel better and certainly done them no harm.
If you know anyone with heart failure who would like to seek advice or participate in StemLife's cardiac cell therapy program, feel free to drop by or give us a call.
StemLife Malaysia: +603 2163 8800 (ask for me)
StemLife Thailand: +662 613 1515-8 (ask for Kostas)
We'd be delighted to set up a no obligations appointment for an honest and friendly consultation.
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