Biomedical Engineering Reference
In-Depth Information
Polypeptide sequences larger than 35 amino acids stretch the limits of clinical
economic viability. Transgenic organisms appear to be the best option for large-
scale synthesis of peptides for use in self-assembling peptide scaffolds (Gelain et
al., 2007a).
Although sapeptides are amino acid-based, the sequences used to create self-
assembling scaffolds are not biologically relevant signaling sequences
promoting cell binding and proliferation. That being said, because they are
peptide-based, it is especially easy to integrate bioactive sequences into the -
sheet structures. These sapeptide structures that include designer application-
dependent bioactive sequences can increase cell proliferation, differentiation
and migration into these hybrid scaffolds as compared with those without the
integrated bioactive sequences (Horii et al., 2007).
10.7
Future trends
The era when surgeons can take tissue constructs off the shelf, like an
automotive mechanic picking through replacement engine pistons, has not
arrived. Although many of the methods presented in this chapter have not yet
reached clinical viability, the myriad of tools available to engineers to solve the
design problems of tissue engineering suggest that a time when off-the-shelf
tissue engineered products are commonly used in clinical practice is not far off.
Well-designed and easily produced matrices will be a necessary component for
making this ideal become a reality.
Despite the promise suggested by the research presented in this chapter, as of
the year 2004, the field of tissue engineering had yet to produce a profitable
product despite the 4.5 billion dollar research and development investment
(Lysaght and Hazlehurst, 2004). In the case of designing matrices for tissue
engineering, researchers should turn an eye to the future and consider what will
be necessary to convert their research into economically and clinically viable
products earlier in the evolution of their research. An increased awareness of
process engineering earlier in the product development could lead to the creation
of more clinically useful and economically viable tissue engineering products
(Archer and Williams, 2005). Tissue engineering research should continue to
move away from proof of principle experiments, and focus more closely to
explore the clinical efficacy and industrial fabrication processes of concepts.
10.8 References and further reading
Archer R, Williams DJ (2005), `Why tissue engineering needs process engineering',
Nature Biotechnology, 23, 1353±1355.
Baker SC, Rohman G, Southgate J, Cameron NR (2009), `The relationship between the
mechanical properties and cell behavior on PLGA and PCL scaffolds for bladder
tissue engineering', Biomaterials, 30, 1321±1328.