New Research Brings Artificial Organs Closer to Reality

Tissue engineering has long been in need of biological "fill material." Blood vessels, nerves, and other small structures lie in a "matrix" of tissue that supports it and facilitates necessary growth of biological structures. A recent news report details the creation of a new type of "bio-gel" that may suit the need.

Scientists at The University of Manchester have created a new type of 'bio-gel' which provides a pH neutral environment for culturing cells in 3D, as published in the journal Advanced Materials (March 2006).

The gel is the first pH neutral material made from combinations of dipeptides (pairs of amino acids) to provide an environment in which cells can be cultured under physiological conditions.

Uniquely, the gel mimics the properties of cell scaffolds which naturally occur in the body and has potential applications for wound healing and tissue engineering.

Cell scaffolds, known as the extra cellular matrix (ECM), are naturally produced by the body to grow new cells in order to repair damaged tissue. Like the ECM, the gel acts like a scaffold in which cells can grow.

In their paper, 'Nanostructured Hydrogels for Three-Dimensional Cell Culture Through Self-Assembly of Fluorenylmethoxycarbonyl-Dipeptides', Dr Rein Ulijn and collaborators describe how the gel is created through a process of self-assembly.

Dr Ulijn said: "We have used combinations of modified dipeptides which act like building blocks and spontaneously assemble into nanometer sized fibres when exposed to physiological conditions, to create a fibrous gel-like structure in which cells can be cultured. Because this material is made up of 99% water and is pH neutral, it is compatible with biological systems.

"By using dipeptide building blocks instead of much larger oligo-peptides used by other researchers, we have greater control over the fibrous architecture and the physical properties of the gels. These materials offer us great potential for future applications in wound healing and regenerative medicine."

Dr Ulijn and his collaborators have successfully cultured cartilage cells using the gel. They found that both the properties of the gels formed and the cell response to the gels could be controlled by using different combinations of di-peptides. The team recently received a £630k award from EPSRC to develop the gels further.

This is good news for tissue engineers, and forward thinking plastic surgeons. With improvements in collagen synthesis, cartilage production, and other basic level tissue engineering processes, the creation of functioning lab-grown organs, complete with support tissue, is much closer.