In the following classic tissue engineering model, a biodegradable scaffold serves as a temporary matrix where implanted cells divide, differentiate and grow into the specific type of tissue cell required, ultimately functioning in the same way as “normal” tissue. In fact, an ideal scaffold functions in much the same way as the body’s own extracellular matrix, allowing normal cellular and physiological processes to occur.
Scaffold-guided tissue regeneration has been used to create the following tissues:
Skin and Cartilage — both of these tissue substitutes are commercially available for treatment of human subjects
Cartilage, Bone, Liver, Nerve and Blood vessels — are in various stages of research and development
ChallengesRegenerative medicine researchers face many challenges in constructing suitable scaffolds, generally related to controlling the spatial distribution of cells, and the proper combination of growth factors, which can have both positive and negative effects on cells, depending on their concentration.
Among the numerous questions being addressed by scientists are these:
- What is the most effective means of seeding the scaffold with cells?
- How readily to cells infiltrate the scaffold?
- What dimensions and composition of scaffold promote the desired distribution of cells?
- How well do cells adhere to the scaffold and how readily can they migrate?
- What physiological effects on the cell result from cell-scaffold interactions?
- Is it possible to selectively vary the concentrations of biochemicals through the scaffold structure?
- What is the lifetime of biochemicals and their effects within the scaffold?
- Do toxic effects result from the interaction of cells, scaffolds and regulatory molecules?