Health Story

03 December 2008 02:07 BST

Advance in tissue regeneration

US scientists have demonstrated how bones can be repaired using tissue grown from human embryonic stem cells.

The process was used to repair holes in the skulls of mice, with the new technique devised by researchers from Baltimore's John Hopkins University.

Using the procedure to heal critical-size defects in intramembraneous bone, the flat bone type that forms the skull, those working on the project were able to demonstrate how human embryonic stem cells can be used in tissue regeneration.

They believe the study is the first to demonstrate the potential application of material derived from human embryonic stem cells to aid musculoskeletal tissue regeneration.

As part of the research, the results of which were presented at the latest annual meeting of the American Society for Cell Biology, researchers took so-called mesenchymal precursor cells from human embryonic stem cells.

The mesenchymal precursor cells, a type of cell capable of giving rise to fat, cartilage, bone and muscle, were then "seeded" onto "scaffolds" - tiny, three-dimensional platforms made from biomaterials which provide a framework on which cells can proliferate, differentiate and form functional tissues.

Large skull injuries in mice were then healed using bone cells which were subsequently generated by the process.

Researchers found the nature of the scaffolds they used to grow the bone cells determined what type of tissue was formed.

The tissue generated to repair the mice skulls used a composite scaffold made of biodegradable polymers and a hard, gritty mineral called hydroxyapatite.

Hydroxapatite caused the mesenchymal precursor cells to become the type of tissue which makes skull, jaw, and collar bones.

Cells grown on an all-polymer scaffold resulted in the formation of endochondral tissue - found in "long" bones such as limbs.