The biotech industry is rapidly expanding and the emerging field of tissue engineering is projected to have a high impact in the near future. Relatedly, in vitro methods for toxicology and drug testing is expected to grow as the ban on animal testing for research purposes is expanded from Europe into North America. The response of many tissue engineered (TE) tissues to external stimuli is overly sensitive, possibly due to a lack of innervation. Recent advances in the construction of innervated TE tissues have demonstrated the importance of nerve-target cell interactions. We have engineered human corneal substitutes that promote nerve in-growth in a pattern similar to in vivo re-innervation. We demonstrate that these nerves (a) are morphologically equivalent to natural corneal nerves; (b) make appropriate contact with target cells; (c) can generate action potentials; (d) respond to chemical and physical stimuli; and (e) play an important role in the overall functioning of the bioengineered tissue. This work demonstrates a role for innervation in the protective quality and function of the engineered tissue, and the potential to use the nerves themselves as indicators of the severity of an insult. This model could also be used as an in vitro alternative to animals for safety and efficacy testing of chemicals and drugs.
See details at: Development of Tissue Engineered, Alternatives to Animal Testing: The Cornea Example