EURON and THEME joint PhD meeting

75
EURON and THEME joint meeting 2011
Development of an in vitro system for the
assessment of axon growth promoting properties of
bioengineered scaffolds
Gerardo-Nava J 1,2 , Grehl T 3 , Weis J 2 , Steinbusch HWM 1 , Brook GA 2 .
1 Maastricht University, School of Mental Health and Neurosciences; 2 RWTH Aachen University Hospital,
Institute of Neuropathology; 3 Ruhr-University-Bochum, Department of Neurology.
An in vitro model capable of studying the axon growth promoting properties of
3D biomaterials will be useful in the development of scaffolds for the repair of
traumatically injured peripheral nervous system (PNS) tissues. The well preserved
cytoarchitectural organization of spinal cord organotypic slice cultures (SCOSC)
as well as hemisected dorsal root ganglia (DRG) are being used to determine
the orientated motor- and sensory axon growth promoting properties of a
3D collagen scaffold. Sensory neurons from hemisected DRGs extended long
and highly orientated SMI32-positive axons throughout the Matricel collagen
microchannels as well as along the surface of the scaffold. Axons that reached
the dorsal horn of the SCOSC crossed the scaffold-SCOSC interface and matrix
crossing it and exploring the target tissue of the DH of the organotypic slice
cultures. Similarly, ventral horn motor neuron axons (also SMI-32 positive) from
the of slice cultures extend within and along the surface of the scaffold. In both
cases, a close interaction between regenerating axonal profiles and NGFr/p75postive
Schwann cells could be seen. Cell migration into the collagen scaffold
was strong in both experimental set-ups and included migration by cells that
were immunoreactive for NGFr/p75, S100, IBA1 and ED1. A more limited degree
of GFAP-positive astrocyte migration was observed close to the SCOSC-scaffold
interface. Earlier in vitro investigations have focused largely on cell-substrate
interactions using cell suspensions and 2D biomaterials. As the field of biomaterial
research advances in the development of 3D scaffolds, the utilization of in vitro
models capable of analyzing the tissue-scaffold interactions may generate much
useful information. In particular, it is hoped that such approaches will eventually
reduce the number of animals required in the development of bioengineering
strategies intended for PNS repair.