Aims: Biosynthetic scaffolds made of degradable bio-materials enriched with cultured cells holds promise for peripheral nerve repair after complex traumatic injuries. In the perspective of future transplantation applications, the aim of this study was to investigate how cultures of olfactory ensheathing cells (OECs), in particular neonatal olfactory ensheathing cells (NOBECs), grow up in vitro on degradable polymeric films made with polycap-rolactone matrices and multi-block polyesterurethane respectively. In addition, since several transplantation studies use green fluorescent protein (GFP) positive cells so that they can be easily located in the receiving tissues, the cDNA encoding for GFP was cloned in expression vector and transfected in NOBECs.
Methods: To characterize NOBECs we employed electron microscopy, immunohistochemistry, RT-PCR and western blotting analyses. Moreover the proliferative ratio of NOBECs and the ability of the cells to migrate in a three dimensional environment were evaluated under basal and experimental culture conditions. Finally, the GFP-positive NOBEC were seeded on two types of synthetic films and their behaviour was analyzed to determine cell adhesion, survival and proliferation.
Results: We examined the expression of glial markers and NRG1/ErbB system in the NOBEC cell line at RNA and protein level. Results showed that NOBECs express both glial markers (GFAP and S-100), ErbB receptors (ErbB1, ErbB2 and ErB3) and different isoforms of NRG1. NOBECs exhibited a remarkable proliferation activity and a high basal migration activity. GFP positive NOBECs showed no significant difference in their behaviour as compared to untransfected parental cells. Finally, both normal and GFP-NOBECs showed good cell adhesion, survival and proliferation properties when seeded on both films employed in this study.
Conclusion: Taken together, results of our study showed that the glial cell line has similar biochemical properties as primary cultures of OECs. Moreover, we showed that NOBECs survive, proliferate and migrate on two different types of synthetic films that were prepared in the perspective of build up nerve scaffolds. Therefore, our results indicated that the NOBECs produce growth-promoting proteins and possess regeneration-promoting capabilities that make them a potentially good transplant material to enhance axonal regeneration inside synthetic tubes used to bridge nerve lesion with substance loss.
