This shows the way to a methodfor restoring damaged heart tissue. Itis astonishing to see just how swiftly we are progressing in this. At the same time, actual methods to outrightreplace a heart with one’s own freshly grown heart is also happening.
The heart is obviously our mostimportant organ that needs this support, though we will soon be applyingsimilar methods elsewhere.
As posted earlier we are enteringa brave new world in which damaged components can be grown in vitro with onesown stem cells and then transplanted into the body in two steps. The first step is to allow the body tointegrate the component and the second step is to remove the damaged component.
The take home is that restorationwill become standard practice inside a few short years now because we aremoving ever faster on this.
MAY 09, 2011
Researchers at Columbia Engineering have established a new methodto patch a damaged heart using a tissue-engineering platform that enables hearttissue to repair itself. This breakthrough, recently published in theProceedings of the National Academy of Sciences (PNAS), is an important step forward in combating cardiovascular disease, one of the most serious health problems of our day.
PNAS - Composite scaffold provides a cell delivery platform forcardiovascular repair
Control over cell engraftment, survival, and function remainscritical for heart repair.
We have established a tissueengineering platform for the delivery of human mesenchymal progenitor cells (MPCs)by a fully biological composite scaffold.
Specifically, we developed amethod for complete decellularization of human myocardium that leaves intactmost elements of the extracellular matrix, as well as the underlying mechanicalproperties. A cell–matrix composite was constructed by applying fibrinhydrogel with suspended cells onto decellularized sheets of human myocardium.
We then implanted this compositeonto the infarct bed in a nude rat model of cardiac infarction. We nextcharacterized the myogenic and vasculogenic potential of immunoselected humanMPCs and demonstrated that in vitro conditioning with a low concentration ofTGF-β promoted an arteriogenic profile of gene expression. When implanted bycomposite scaffold, preconditioned MPCs greatly enhanced vascular networkformation in the infarct bed by mechanisms involving the secretion of paracrinefactors, such as SDF-1, and the migration of MPCs into ischemic myocardium, butnot normal myocardium. Echocardiography demonstrated the recovery of baselinelevels of left ventricular systolic dimensions and contractility when MPCs weredelivered via composite scaffold. This adaptable platform could be readilyextended to the delivery of other reparative cells of interest and used inquantitative studies of heart repair.
Led by Gordana Vunjak-Novakovic, professor of Biomedical Engineering atColumbia University’s Fu Foundation School of Engineering and Applied Science,the researchers developed a novel cell therapy totreat myocardial infarction (heart damage that follows a heart attack). Theywere able, for the first time, to combine the use of human repair cells thatwere conditioned during in-vitro culture to maximize their ability torevascularize and improve blood flow to the infarcted tissue with a fullybiological composite scaffold designed to deliver these cells to the damagedheart. With this platform, they could both keep the cells within the infarctbed (in contrast to the massive cell loss associated with infusion of cellsalone) and enhance cell survival and function in the infarct bed, wheremost of the cells would have died because of the obstruction of their bloodsupply.
“We are very excited about this new technique,” said Dr. Vunjak-Novakovic.“This platform is very adaptable and we believe it could be readily extended tothe delivery of other types of human stem cells weare interested in to rebuild the heart muscle and further our research of themechanisms underlying heart repair.”
In effect, the
“It really is encouraging to make progress with ‘instructing’ cells to formhuman tissues by providing them with the right environments,” noted Dr.Vunjak-Novakovic. “The cells are the real ‘tissue engineers’—we only design theenvironments so they can do their work. Because these environments need tomimic the native developmental milieu, the progress in the field is reallydriven by the interdisciplinary work of bioengineers, stem cell biologists,and clinicians. By enabling regeneration and replacement of our damagedtissues, we can help people live longer and better.”
Dr. Vunjak-Novakovic and her team already have several active research projectsthat continue this line of work. They are now investigating the formation of acontractile cardiac patch using human stem cells thatcan give rise to both the muscle and vascular compartments of the heart muscle.They are also studying how the cells within such a cardiac patch, whenimplanted on infarcted heart tissue, develop their ability to generatemechanical force and electrical conduction, and how these functions can bemodulated by in-vitro culture.
“Ultimately, we envision this system as a possible point of care approach,”said Dr. Vunjak-Novakovic, “with components actually produced and assembled inthe operating room to most effectively target-signaling mechanisms involved inthe repair process of someone’s damaged heart.”
I also added this video. You may need go join Newsy to properly uses it.
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