Affiliations: Department of Neurosurgery, C.H.U. Sart Tilman,
University of Liège, Belgium | Laboratory of Connective Tissues Biology, C.H.U. Sart
Tilman, University of Liège, Belgium
Note: [] Correspondence to: Department of Neurosurgery, C.H.U. Sart
Tilman, B 35, 4000 Liège, Belgium. Phone: +32-4-3667208; Fax:
+32-4-3667737.
Abstract: Our aim is to devise an artificially reconstituted nerve segment
made of a three-dimensional collagen gel populated with aligned fibroblasts and
Schwann cells. Collagen lattices were prepared by mixing concentrated medium, a
type I collagen solution and rat Schwann cells (SC), rat neural fibroblasts
(nF) or human dermal fibroblasts (dF) and allowed to polymerize at 37 °C.
In these free-floating lattices, nF and dF retracted the gel more than SC. All
cells appeared to be elongated and oriented at random. Rat cells obtained by
enzymatic digestion of nerves undergoing wallerian degeneration retracted the
gel at a larger extent than cells from intact nerves. Rectangular lattices
restrained at each extremity acquired a paraboloid shape upon retraction by
neural or dermal F reflecting the mechanical tension developed by these cells
on their support. Adult SC alone produced a faint paraboloid even at high cell
density while SC associated with nF developed a paraboloid similar to that
obtained with nF alone. The mechanical force developed by dermal F and SC in
the restrained lattice was measured by strain gauges and found much higher for
F than for SC. In restrained lattices, both types of F were elongated and
aligned to the long axis of the gel while SC elongated but not necessarily in a
parallel fashion. The central portion of a mixed nF-SC collagen restrained
lattice produces a flattened cylindric segment made of longitudinally oriented
col-lagen fibrils, F and SC, which could represent a promising material for
preparation of nerve grafts. An original plastic mould was devised to allow the
preparation of cylindrical segments of free or restrained collagen lattices in
view of in vitro and in vivo regeneration studies.
