Current model
A three-dimensional model of the left ventricle, which is a nanofiber frame, populated by cells of the heart muscles.
Researchers at Harvard University, working under the guidance of Professor Keith Parker (Parker Kit) have created a bioengineered three-dimensional model of the left ventricle of the human heart, which can be used to study diseases and test drugs and develop customized methods of treating diseases of the heart, such as arrhythmia.
The key to creating a functional cardiac ventricle is a reproduction of the unique composition of the fabric. In the heart of a living organism are arranged parallel to each other of the myocardial fibers act as a frame for the correct location of cardiomyocytes that form a hollow conical structure. When the heart cells consistently stretch and shrink.
To create an artificial framework, the authors used platform for the production of nanofibers, known as Poole-spinning (pull spinning). This approach uses a rotating roller, which is immersed in a tank of polymer and pulls the drop in the stream. Fiber moves along a spiral trajectory and hardens to the separation of the roller and moving to the collector.
To create ventricle, the researchers used a combination of biodegradable fibers from polyester and gelatin collected on a rotating collector, having the shape of a bullet. Due to the rotation manifold fibers aligned in one direction.
Thus formed a three-dimensional frame was settled by myocytes of the rat or human cardiomyocytes derived from induced pluripotent stem cells. Within 3-5 days of the frame was covered with a thin layer of tissue and are located parallel to each other cells began synchronously to contract. From this point, the researchers were able to regulate and track the movement of calcium ions and to use a catheter for the study of the pressure-volume cutting of the ventricle.
Attached to the catheter bioengineering ventricular myocytes from newborn rats spontaneously reduced.
The authors influenced formed the fabric of isoproterenol, a drug, which is similar to the effect of adrenaline, and estimated the increase in frequency of contractions. They also pierced the holes in the fabric of artificial ventricle, simulating myocardial infarction, and studied the effects of developing a heart attack in vitro.
To examine the functioning ventricle for long periods of time was developed Autonomous bioreactor, with a separate chamber for the introduction of various valves, and additional ports for catheters and other support tools. All this provides the opportunity to study the functions of artificial ventricle using conventional clinical methods, such as the assessment loop "volume-pressure" and ultrasonography.
This device is allowed to cultivate ventricle of cardiomyocytes for 6 months. In the future, the authors plan to settle nanofiber frame pre-differentiated cells of patients, to ensure more efficient production myocardial tissue. Such artificial ventricles can be used to study the progression of diseases as well as for individual selection of the most effective methods of treatment.
According to the authors, their group is working on the development of an artificial heart for over 10 years, and getting artificial ventricle is a very serious achievement. They began their work with the study of methods for obtaining cardiomyocytes, then gradually moved on to creating the cardiac muscle tissue and muscle pumps. In the course of work they have clarified some of the fundamental principles of structure muscle pumps and formulated the ideas of the approaches for the restoration of damage to the heart in cases when these laws are violated diseases. They recognize that there is still a long way to creating a fully 4-chambered hearts, but lately, the progress is greatly accelerated.
Article Luke A. MacQueen et al. A tissue-engineered scale model of the heart ventricle published in the journal Nature Biomedical Engineering.
Eugene Ryabtsev, the portal of "Eternal youth" http://vechnayamolodost.ru on materials from Harvard University: A 3-D model of a human heart ventricle.