Spatial‐Temporal progress of peripheral nerve regeneration within a silicone chamber: Parameters for a bioassay

Abstract

The spatial-temporal progress of peripheral nerve regeneration across a 10-mm gap within a silicone chamber was examined with the light and electron microscope at 2-mm intervals. A coaxial, fibrin matrix was observed at 1 week with a proximal-distal narrowing that extended beyond the midpoint of the chamber. At 2 weeks, Schwann cells, fibroblasts, and endothelial cells had migrated into the matrix from both nerve stumps. There was a delay of 7-14 days after nerve transection and chamber implantation before regenerating axons appeared in the chamber. At 2 weeks, nonmyelinated axons were seen only in the proximal 1-5 mm of the chamber in association with Schwann cells. Axons reached the distal stump by 3 weeks and a proximal-distal gradient of myelination was observed. These observations define the parameters of a morphologic assay for regeneration in this chamber model which can be used to investigate cellular and molecular mechanisms underlying the success of peripheral nerve regeneration.

Efecto de la permeabilidad en la regeneración del nervio ciático entubado de rata

“…Esta estructura es similar a otras ya descritas en la literatura utilizando este sistema experimental (6,8,9). La matriz presenta un aspecto difuso y contiene esencialmente células sanguíneas y fibrina.…”

“…El modelo de la entubación se ha convertido en una herramienta experimental muy útil para el estudio de los fenómenos básicos subyacentes en la regeneración del nervio periférico (1-3). Las guías tubulares que se han utilizado son hechas de diversos materiales y permeabilidades: sintéticas impermeables, semipermeables o totalmente permeables; biodegradables o de origen biológico (4)(5)(6)(7)(8)(9). En la rata, los tubos de silicona impermeable permiten la regeneración de un mayor número de fibras mielinicas que los tubos acrilicos semipermeables (10).…”

“…Cuatro semanas de supervivencia: para los tres grupos experimentales, la organización histológica básica es similar a otras descripciones ya publicadas (6,9); en términos generales, se observa un puente circular de tejido conectivo, altamente vascularizado y colonizado por células de Schwann y fibras nerviosas mielínicas (figura 4A). Sin embargo, nuevamente se observa una diferencia importante entre los tubos con 9 agujeros y los otros.…”

Estudo experimental comparativo da ação das neurocinas cardiotrofina-1 e oncostatina-m na regeneração nervosa periférica

“…Apesar In spite of discordance (KIYOTANI et al, 1996;SUZUKI et al, 1999), several trials studied the axonal growth through empty tubes and concluded that 10 mm was the maximum distance to achieve an appropriate regeneration (BRUNELLI et al, 1994;DEN DUNNEN et al 1996;FRANCEL et al, 1997 (LUNDBORG et al 1982;WILLIAMS et al 1983;DA SILVA, 1987;LANGONE, 1991).…”

The effect of intraluminal contact mediated guidance signals on axonal mismatch during peripheral nerve repair

“…These advantages include limiting myofibroblast infiltration, a reduction in scar and neuroma formation, and no associated donor pain [14]. However, hollow conduits provide only limited structural support (in the form of a fibrin cable) and guidance to regenerating axons and as a result functional recovery remains poor [6,8,15]. To overcome the limitations of the use of hollow conduits, intraluminal guidance structures (e.g.…”