NEUROCAP: natural artificial limbs
The goal of this project is to develop a highly selective neuroprosthesis for artificial hand control in amputees. The prosthesis is a neural endcap device. The problem with previous devices is that neural regeneration is hampered by fasciculation of regenerating axons.
This in vitro and in in vivo study shows that the fasciculation mechanism can be manipulated by providing an appropriate microchannel scaffold to guide and influence growth, thereby achieving a high degree of selectivity. The microchannels employed have a bifurcation from a primary channel into two secondary channels. This bifurcating microstructure was able to support and promote fasciculated growth over 70% of the time for microchannels widths of 2.5, 5, 10 and 20 μm, in vitro and also (for wider channels only) in vivo. Fasciculation is shown to be a strong force during ingrowth, with the initiation of neurite separation related to random spatial exploration. Narrower microchannels initiate separated
growth better. The reduction from 20 μm to 10 μm wide channels also
resulted in a 3-fold decrease in ingrowing neurites performing 180◦ turns to exit the microchannel via the entrance.
A second advantage of guided channel growth and separation is that neural signals recorded inside the channels have largely increased amplitudes of action potentials, making recording of these tiny signals easier and more reliable.
Eddy de Weerd
Karin Groot Jebbink