Abstract:

The last decade has seen a steady proliferation in the use of tissue-engineered cell culture systems, and these have been put to good use for studying neural axon growth and guidance. These systems have been designed to more closely mimic the natural microenvironment of the developing or repairing nervous system and to enable spatiotemporal control over certain aspects of the microenvironment. The 3D nature of these culture systems provides a more physiologically-relevant microenvironment, while spatiotemporal control addresses aspects of tissue architecture and molecular presentation for quantitative investigation into how specific physical or molecular variables might influence axon growth. These capabilities should be tremendously important to the study of neural regeneration, since it is well known that developing and regenerating axons of both the central and peripheral nervous systems respond to particular attractive or repulsive cues presented in their microenvironments that may be sensed by the growth cones of these extending axons. Tissue-engineered model systems are well suited to the investigation into precise mechanisms of action of these cues, the elucidation of novel mechanisms, and for testing potential therapeutic strategies.
To date, biologists have yet to fully leverage the engineering developments of these model systems for neural regeneration research. This is important because molecular neuroscientists, who are trained for hypothesis-driven research, are arguably better suited to the utilization of these models than bioengineers (such as this author), who may be better suited to their design and validation. The main barriers to adoption of these tools are somewhat obvious: nonstandardized techniques and the need for specialized equipment, devices, and materials. But a more subtle barrier arises because engineers and molecular biologists approach problems differently, frequent different circles, and speak different scientific languages. These differences lead various fields of experts to ignore the advances or dismiss the methodologies of those in other fields, though they may be most relevant. Tissue-engineered culture models have come of age, and are poised to play an integral role in neural regeneration research. For this to occur, the technical and intellectual barriers to adoption of these models can and must be overcome.