Regenerative medicine and tissue engineering are fields that emerge from the growing ability to control cells and cellular behavior. Complete control over cells will one day be the basis for the vast majority of all medicine dealing with natural, unmodified humans. Little is left beyond that arena aside from the removal of metabolic waste products that cells are not equipped to destroy. However, this is a narrow view of the future. Long before complete cellular control is achieved researchers will already be modifying cells and their components: building better and more reliable machinery, augmenting or replacing the evolved components of a cell and a body one by one. So at the same time as fields emerging from cellular control take over near-all medicine, they themselves will be transformed and made obsolete by the growing ability to replace our evolved biology with something better.
But this dynamic will play out a way down the line. It is interesting to look ahead, and also to keep an eye on areas in which replacements for evolved cellular components could happen comparatively soon, such as in the development of artificial mitochondria. If you are interested in the impact on your future health and life, it is control over - and the ability to repair - our present biology that is the most important line of research and development. That is work that has the best chance of extending healthy life spans soon enough to matter to you and I.
There is a lot going on in the energetic fields of cell research, and it is fortunate that the interests of the researchers involved are largely aligned with those of life extension supporters. Most of the medical conditions that would benefit the most from cell therapies are age-related, and thus researchers have a strong incentive to figure out how to make their work effective in old tissues. This will require them to provide solutions for a number of the aspects of degenerative aging, such as the changes in signaling protein levels that reduce stem cell activity, the dysfunction of the aged immune system, and so forth. With that in mind, here is a random selection of recent work in regenerative medicine and tissue engineering.
Every muscle has satellite cells on reserve, ready to activate upon injury and begin the regeneration process. The key to the team's success was successfully creating the microenvironments - called niches - where these stem cells await their call to duty. "Simply implanting satellite cells or less-developed muscle doesn't work as well. The well-developed muscle we made provides niches for satellite cells to live in, and, when needed, to restore the robust musculature and its function."
To put their muscle to the test, the engineers ran it through a gauntlet of trials in the laboratory. By stimulating it with electric pulses, they measured its contractile strength, showing that it was more than 10 times stronger than any previous engineered muscles. They damaged it with a toxin found in snake venom to prove that the satellite cells could activate, multiply and successfully heal the injured muscle fibers.
We used a microdialysis technique to show that, after a heart attack, local enzyme levels go way up, but when the inhibitor molecules are delivered via the gel, we see the activity level of this enzyme go down. Over the next 28 days, we also used imaging techniques to show thicker cardiac walls and less expansion and dilation of the ventricle. And, as a result, we see better performance in the heart using clinical measurements like ejection fraction, the amount of the blood the heart is pumping.
While most groups working in this field are attempting to develop myocardial regenerative therapies, our team is focused on the biomechanical stabilization of the heart after heart attack. Most researchers working towards regenerative therapies often overlook an important fact, namely, that the overwhelming majority of patients who suffer heart attack initially have adequate heart function. We strongly believe that optimizing the function of the surviving heart muscle after heart attack will be a more realistic and effective strategy than trying to regenerate the muscle that is lost.
The study is the largest placebo-controlled double-blind randomized trial to treat patients with chronic ischemic heart failure by injecting a type of stem cell known as mesenchymal stromal cells directly into the heart muscle. The study included 59 patients with chronic ischemic heart disease and severe heart failure.
Six months after treatment, patients who received stem cell injections had improved heart pump function compared to patients receiving a placebo. Treated patients showed an 8.2-milliliter decrease in the study's primary endpoint, end systolic volume, which indicates the lowest volume of blood in the heart during the pumping cycle and is a key measure of the heart's ability to pump effectively. The placebo group showed an increase of 6 milliliters in end systolic volume.