The inner diameter of the tube is 0.5 millimetres and its height is about 1 millimetre, making it the size of the ventricle in a human fetus at about the 19 th week of gestation. The result: a tube composed of three overlapping layers of heart cells that beat in unison, pumping fluid out of the hole at the end. After seeding the scaffold with cells and allowing them to grow for about a week, the researchers rolled the sheet around a hollow polymer shaft, which they call a mandrel. Electrical pulses can even be used to control how fast they beat – a kind of training gym for the heart tissue.įor the bioartificial left ventricle, Okhovatian and Mohammadi created a scaffold shaped like a flat sheet of three mesh-like panels. The underlying shape or pattern of the scaffold encourages the growing cells to align or stretch in a particular direction. Over time, the living cells grow together, forming a tissue. The scaffolds, which are often patterned with grooves or mesh-like structures, are seeded with heart muscle cells and left to grow in a liquid medium. To move into three dimensions, Radisic and her team use tiny scaffolds made from biocompatible polymers. Many of the challenges facing tissue engineers relate to geometry: while it’s easy to grow human cells in two dimensions – for example, in a flat petri dish – the results don’t look much like real tissue or organs as they would appear in the human body. We can also use them to screen large libraries of drug candidate molecules for positive or negative effects.” “With these models, we can study not only cell function, but tissue function and organ function, all without the need for invasive surgery or animal experimentation. “The unique facilities we have at CRAFT enable us to create sophisticated organ-on-a-chip models like this one,” Radisic says. A unique partnership between Canada’s National Research Council and U of T, CRAFT is home to world-leading experts who design, build and test miniaturized devices to control fluid flow at the micron scale, a field known as microfluidics. Their multidisciplinary team was led by Milica Radisic, a professor in the department of chemical engineering and applied chemistry and senior author of the paper.Īll three researchers are members of the Centre for Research and Applications in Fluidic Technologies (CRAFT). Okhovatian and Mohammad Hossein Mohammadi, who graduated from U of T with a master's in chemical and biomedical engineering, are co-lead authors on a new paper in Advanced Biology that describes the model they designed. “Both of these were nearly impossible to get with previous models.” “With our model, we can measure ejection volume – how much fluid gets pushed out each time the ventricle contracts – as well as the pressure of that fluid,” says Sargol Okhovatian, a PhD candidate in the Institute of Biomedical Engineering. The new lab-grown model could offer researchers a new way to study a wide range of heart diseases and conditions, as well as test potential therapies. In the human heart, the left ventricle is the one that pumps freshly oxygenated blood into the aorta, and from there into the rest of the body. The bioartificial tissue construct is made with living heart cells and beats strongly enough to pump fluid inside a bioreactor. Hence, results suggested that fabricated scaffolds have huge prospective as a bioactive, well-designed and economical scaffold stand for tissue engineering application.University of Toronto researchers in the Faculty of Applied Science & Engineering have grown a small-scale model of a human left heart ventricle in the lab. Their tensile strength and water absorption capacity were improved, but pore size and porosity were decreased after incorporation of gelatin. The results revealed that the gelatin contributed to the enhanced cell attachment and proliferation over the scaffolds, whereas cellulose as a strong backbone in the scaffold to support it for keeping its appearance. The physicochemical and mechanical properties of the scaffolds were characterized. Microfibers-based scaffold could overcome the limitations of nanofibrous material-based scaffold for tissue engineering application. In this work, the gelatin-coated microfibrous paper scaffold was fabricated successfully by a papermaking process. Therefore, cotton would be good raw material to design a scaffold for tissue engineering applications. Cotton is cheap, easily available and widely used as surgical material.

Tissue engineering scaffold