Following an examination of embryonic development, scientists have made an advancement in tissue engineering. Scientists from the Harvard School of Engineering and Applied Sciences (SEAS) have been able to develop a new gel-based material, which they say can allow stem cells to repair damaged caused to bones and teeth. What is truly noteworthy is that the gel is able to shrink and effectively copies the physical conditions that occur when  tissue forms naturally.

In developing this gel the scientists took in to account the process known as mesenchymal condensation, which is a critical transitional stage that precedes cartilage formation during embryonic development. Mesenchymal cells, which are a type of stem cell, develop in to mature cells such as bone and enamel.


At SEAS the scientists simulated the compression that mesenchymal cells normally experience during the mesenchymal condensation process. They used a modified form of PNIPAAm polymer as the base of the gel so that it contracted at body temperature. The loose form of the gel was filled with mesenchymal cells and then as the gel was warmed, they were compressed, resulting in a differentiation of cell types and new tissue was formed.

Getting human cells to form in to 3D structures in a lab environment has been a real problem for tissue engineers but this bio-inspired gel could be a big step in helping them understand and overcome the problems.

“Tissue engineers have long raised the idea of using synthetic materials to mimic the inductive power of the embryo,” said senior author Don Ingber, founding director of the Wyss Institute, Judah Folkman Professor of Vascular Biology at Harvard Medical School, and Professor of Bioengineering at SEAS. “We’re excited about this work because it shows that it really is possible.”

The next step for the scientists is to test the gel with layers of mesenchymal cells and epithlial cells to see if they can form a full tooth. If successful, this coulld lead to the development of other tissue types.

[Image via Scicasts]