Artificial Cartilage Implant

Boston, MA-

Artificial joints and components generated in vitro for surgical implantation in patients with injured joints is an area of intense research and commercialization interest.

Hydrogels are generally defined as a network of polymer chains that are water-soluble and can be used for implantation of drugs or cells into a desired anatomical area. In a recent paper (Hannouche D et al. Engineering of Implantable Cartilaginous Structures from Bone Marrow-Derived Mesenchymal Stem Cells. Tissue Eng. 2006 Dec 1;) the use of biodegradable hydrogels with a structural supporting polyglycolic acid (PGA) scaffold was used to allow for generation of three dimensional artificial cartilage tissue using mesenchymal stem cells as a source of chondrocytic precursors.

The researchers also assessed the impact of a gel made of collagen type I, as well as alginate (sea-weed derived polymer used commonly in making molds) on the polyglycolic acid scaffold to alter the differentiation of the mesenchymal stem cells into cartilage.

Briefly the experiments performed included:
1. Isolating mesenchymal stem cells from rabbits
2. Expanding said cells in monolayers
3. Suspend cells in the hydrogel
4. Load the hydrogel into the polyclycolic acid constructs
5. Cell-seeded constructs were grown in special bioreactors in TGF-beta but with no serum

At the end of growth...

1. The constructs looked like cartilage (ie white and appeared shiny)
2. The constructs thickened in a time-dependent manner
3. Collagen II and hyalin-like ECM was found in all constructs

But they did not implant them into animals...