Stem cell, Granulocyte-Colony Stimulating Factor and/or Dihexa to promote limb function recovery in a rat sciatic nerve damage-repair model: Experimental animal studies.

Animal study investigating the effects of mesenchymal stem cells, G-CSF, and Dihexa on limb function recovery after sciatic nerve transection and repair in rats.

“We investigated whether administration of mesenchymal stem cell (MSC), Granulocyte-Colony Stimulating Factor (G-CSF) and/or Dihexa can improve recovery of limb function following peripheral nerve damage in rat sciatic nerve transection-repair model.”

Male Lewis rats.

“Ten to 12-week-old inbred male Lewis (RT1l) rats, weighing ∼300 g were purchased from Harlan Sprague Dawley (Indianapolis, IN).”

10 experimental groups with 6 to 8 rats per group.

“There were 10 experimental groups (n = 6–8 rats/group).”

16 weeks post-nerve repair.

“The limb sensory and motor functions were assessed at 1–2 week intervals post nerve repair until the study endpoint (16 weeks).”

Sensory function in all nerve boundaries returned to nearly normal by 8 weeks in all groups.

“The sensory function in all nerve boundaries (peroneal, tibial, sural) returned to nearly normal by 8 weeks (Grade 2.7 on a scale of Grade 0–3 [0 = No function; 3 = Normal function]) in all groups combined.”

Motor function significantly improved with MSC + G-CSF or MSC + Dihexa administrations into gastrocnemius muscle.

“Motor function at 8–16 weeks post-nerve repair as determined by walking foot print grades significantly (P < 0.05) improved with MSC + G-CSF or MSC + Dihexa administrations into gastrocnemius muscle and mitigated foot flexion contractures.”

Foot flexion contractures were significantly reduced in groups receiving G-CSF + MSC or Dihexa + MSC administration into gastrocnemius muscle compared to vehicle control.

“Flexion contracture was significantly (P < 0.01) reduced in Group 7 (Grade 1.2) that received G-CSF + MSC administration into gastrocnemius muscle and in Group 8 (Grade 1.8) that received Dihexa + MSC administration in to gastrocnemius muscle when compared to vehicle control group 10 (Grade 3.2).”

Sensory function was assessed by manual pinching rather than electrostimulation, and physiotherapy was manual rather than using a treadmill.

“We evaluated the sensory function by manually pinching the nerve boundary with forceps and recorded response, which is a standard and acceptable methodology. However, electrostimulator is preferred to precisely stimulate nerve boundaries at particular stimulus strength consistently in all animals and measure the response.”