Scaffolds for skeletal tissue engineering
Scaffolds are three-dimensional supports that are being developed and evaluated at Sheffield to increase the quality of the tissue that can be successfully engineered. The cells may grow to adopt the shape of the scaffold, so this feature can also be used to generate an implant tissue of the correct shape.
Scaffolds may be "active" (helping direct cell growth) or "inert" (simply providing a shape for the final tissue), and both types are in use and development in different groups at Sheffield.
More complex scaffolds, such as the composite osteochondral scaffold have been developed for co-engineering cartilage and bone for articular joint repair. These are two-phase scaffolds, with one area that integrates into the sub-chondral bone, and holds the tissue engineered cartilage pad in place above it. This is important as cartilage implants have a limited capacity to re-integrate with native cartilage.
Above right: Chondrocytes growing in a non-woven scaffold. Fibres of the scaffold appear as black dots or short lines in this section, in which the extracellular matrix has been stained purple, and the cells are visible as darker blue flecks.
A number of scaffolds have been investigated for their suitability as cartilage scaffolds at Sheffield. These include:
- Polymer-ceramic composite scaffolds for osteochondral tissue engineering.
- Porous calcium phosphate ceramic scaffolds for bone tissue engineering.
- Hydrogels for tissue engineering and related applications.
- Surface modification using plasma polymers.
- Chitosan and other natural polymer scaffolds
- Silk proteins
The physical form of the scaffold is also important. We have found that Chondrocytes prefer fibrous scaffolds, within which they can lay down the correct Collagen type II matrix.
Researchers engaged in this work are Richard Ackbar, Prof. Ian Brook, Dr Aileen Crawford, Rebecca Goodchild, Prof. Paul Hatton, James Lapworth, Ana MacIntosh, Dr Steve Rimmer. (PhD project by Jon Collett, 2005)