Effect of Schwann Cells in the Enhancement of Peripheral-Nerve Regeneration

Abstract

Schwann cells appear to stimulate the early phases of axon regeneration. The reported study investigated whether nerve guides with Schwann-cell monolayers can help regenerating nerves span gaps larger than 1 cm. Schwann-cell cultures were established by resecting 1-cm segments of sciatic nerves of adult female Sprague-Dawley rats, establishing cell monolayers in 24-mm nerve guides, and then reinserting these "living guides" into 20-mm nerve gaps of the rats from which they were developed. Control groups had plain guides (no Schwann cells) inserted between the same 20-mm gaps. In the experimental group, resected nerves regrew progressively. At 8 weeks, regrowth had spanned the entire gap in 60 percent of the animals. Axon counts increased at each successive time point. Regeneration did begin to occur in the control group but by 8 weeks, those cables had atrophied. The experimental groups displayed more central connections and higher nerve conduction velocity. Explant organ cultures of rat sciatic nerve can be used to develop nonneural conduits with Schwann-cell monolayers. These living artificial nerve guides permit the spanning of gaps of at least 20 mm.

Behavioral evaluation of regenerated rat sciatic nerve by a nanofibrous PHBV conduit filled with Schwann cells as artificial nerve graft

“…As shown by Williams et al (1983), SCs may have an impact on peripheral nerve regeneration in the early phases. Bryan et al (1996) investigated this " early impact " by bridging a 20 mm, a fairly long, nerve gap in a rat model by using a poly-L-lysine pre-coated polyethylene guide fi lled with pre-established SCs. Cell-seeded guides had better results in axon counts and nerve conduction velocity.…”

Poly(Lactic-Co-Glycolic Acid) Based Drug Delivery Devices For Tissue Engineering And Regenerative Medicine

“…Shive and Anderson (69) injected rats intramuscularly in the leg with norethistrone or lypressin microspheres prepared with radiolabelled PLGA microspheres of varying lactide:gycolide mole ratio in order to determine the biodegradation kinetics of microspheres prepared with lactide/gycolide exipients. The radiolabel was incorporated into the excipient by using 14 C-DL-lactide monomer during its polymerization. Altering the chemical composition by increasing the gycolide mole ratio in the copolymer increases the rate of biodegradation ( Fig.…”

Biodegradable Cell-Seeded Nanofiber Scaffolds for Neural Repair

“…Schwann cells, the principal glia cells of PNS, facilitate both peripheral and central nerve regeneration by providing a permissive environment. Shortly after injury, Schwann cells divide rapidly, move to the injury site, express a completely different set of genes, and stimulate axonal regrowth, the key element in functional restoration of nerves at the early stages [196][197][198][199][200][201][202]. In response to axonotmesis injury, in which the axon is injured but the myelin sheath remains intact, Schwann cells form aligned paths, termed bands of Büngner, which guide regenerating axons in peripheral nerves [200].…”

“…As shown by Williams et al and others [196][197][198][199][200][201][202], Schwann cells may have an impact on peripheral nerve regeneration in the early phases. Bryan et al [197] investigated this "early impact" by bridging a 20-mm, a fairly long, nerve gap in a rat model by using a poly-L-lysine precoated polyethylene (PE) guide filled with pre-established Schwann cells. Cell-seeded guides had better results in axon counts and nerve conduction velocity.…”

“…Cell-seeded guides had better results in axon counts and nerve conduction velocity. The positive impact of Schwann cells on the repair process might be due to the directing cue that Schwann cells provided [197]. Rodriguez et al [209] investigated the influence of syngeneic (genetically identical), isogeneic (genetically alike) and autologous Schwann cells, respectively, on peripheral nerve regeneration using a mouse model.…”