How can you mend a broken heart?
Cardiologists have been wrestling with this question for years. The difficulty is that when one suffers a myocardial infarction (heart attack), the lack of blood supply to certain parts of the heart can eventually cause myocardial scarring. Myocardial scarring can lead to potentially life-threatening arrhythmias and increase the risk of a ventricular aneurism. Moreover, the loss of this healthy heart tissue is essentially permanent. Part of the heart literally dies.
However, advances in nanotechnology have allowed researchers at Brown University to investigate the use of carbon nanotubes to regenerate cardiomyocytes and neurons. Using carbon nanotubes and a polymer as a kind of scaffold, they seeded it with cardiomyocytes.
Why use carbon nanotubes instead of just a polymer scaffold, you may ask? According to the researchers:
“The carbon nanofibers work well because they are excellent conductors of electrons, performing the kind of electrical connections the heart relies upon for keeping a steady beat. The researchers stitched the nanofibers together using a poly lactic-co-glycolic acid polymer to form a mesh about 22 millimeters long and 15 microns thick and resembling, a black Band Aid.” They laid the mesh on a glass substrate to test whether cardiomyocytes would colonize the surface and grow more cells.
According to the results, after only four hours, there were five times as many cardiomyocytes on the carbon nanotube-containing scaffold than on the control, polymer-only one. After five days, the density was six times that of the control sample. As for neuron growth, the density of neurons also greatly increased, doubling after four days.
O enfarte do miocárdio ocorre devido a um processo de necrose (morte do tecido) de uma parte do músculo cardíaco por falta de aporte adequado de nutrientes e de oxigénio. Isto acontece devido a uma interrupção brusca e grave no fluxo sanguíneo, podendo levar à morte, sendo actualmente a principal causa de morte nos países industrializados. Por isso, muitos estudos têm sido desenvolvidos com o intuito de descobrir novas técnicas de prevenção e, principalmente, de tratamento, de forma a minimizar as consequências no organismo humano.
ResponderEliminarEstes investigadores encontraram assim uma solução para regenerar o tecido cardíaco morto, para tal utilizam nanotubos de carbono juntamente com um polímero, nos quais semearam células do tecido cardíaco e encontraram condições favoráveis à sua adesão e proliferação, o que promoveu a “ressuscitação” da área lesada.
Estudos realizados in vitro e in vivo vieram comprovar a biofuncionalidade e biocompatibilidade deste biomaterial quando implantado no Homem.
Assim, este nano-dispositivo pode tornar-se uma esperança para as pessoas que sofreram um ataque cardíaco.