A fundamental challenge of tissue engineering that has been successfully addressed in research and by a number of companies developing tissue engineering for therapeutics (Organovo, 3DM, Advanced BioHealing, ISTO Technologies, BioTissue Technologies, BioSyntech, others) is the formation of functional, three-dimensional tissues.
This is particularly important for bone tissue engineering, in which the 3D structure must to serve as a substitute for bone under both static and dynamic, weight-bearing conditions, and must be resorbed at an appropriate rate. Even skin, which might simplistically be viewed as two dimensional, requires a three dimensional structure in tissue engineered products (see Dermagraft by Advanced BioHealing).
A good example of 3-D scaffold technology is that of ISTO Technologies:
ISTO has also developed a biomaterial platform for tissue repair that is used to create a variety of scaffold-based products for tissue-engineering applications. ISTO’s biomaterial platform is composed of synthetic poly(lactide-co-glycolide) (PLGA) and hyaluronic acid (HyA). PLGA is an excellent biomaterial for constructing three-dimensional tissue scaffolds; however, because of its innate hydrophobicity it is not optimal for cell penetration and attachment. To overcome this limitation, ISTO developed a process whereby HyA is entangled within the PLGA backbone structure, creating a hydrophilic scaffold that supports migration and attachment of cells. In addition to facilitating exchange of water and ions within tissues, HyA is reported to play a central role in skeletal development and tissue repair. The first commercial application of ISTO’s biomaterial technology is for bone healing.
Source: ISTO Technologies; MedMarket Diligence report #S520.
See also a recent post on the formation of 3D structures for micro-fluidic channels.