Peripheral nerve regeneration by microbraided poly(L‐lactide‐co‐glycolide) biodegradable polymer fibers

Abstract

Tiny tubes with fiber architecture were developed by a novel method of fabrication upon introducing some modification to the microbraiding technique, to function as nerve guide conduit and the feasibility of in vivo nerve regeneration was investigated through several of these conduits. Poly(L-lactide-co-glycolide) (10:90) polymer fibers being biocompatible and biodegradable were used for the fabrication of the conduits. The microbraided nerve guide conduits (MNGCs) were characterized using scanning electron microscopy to study the surface morphology and fiber arrangement. Degradation tests were performed and the micrographs of the conduit showed that the degradation of the conduit is by fiber breakage indicating bulk hydrolysis of the polymer. Biological performances of the conduits were examined in the rat sciatic nerve model with a 12-mm gap. After implantation of the MNGC to the right sciatic nerve of the rat, there was no inflammatory response. One week after implantation, a thin tissue capsule was formed on the outer surface of the conduit, indicating good biological response of the conduit. Fibrin matrix cable formation was seen inside the MNGC after 1 week implantation. One month after implantation, 9 of 10 rats showed successful nerve regeneration. None of the implanted tubes showed tube breakage. The MNGCs were flexible, permeable, and showed no swelling apart from its other advantages. Thus, these new poly(L-lactide-co-glycolide) microbraided conduits can be effective aids for nerve regeneration and repair and may lead to clinical applications.

The role of aligned polymer fiber-based constructs in the bridging of long peripheral nerve gaps

“…Topographical cues involving grooves and fibers have been previously demonstrated to cause Schwann cell alignment and subsequent neurite extension in vitro [13][14][15], and some studies have used magnetically aligned collagen filaments [16], microbraided polymer fibers [3], or micron-scale filaments to promote nerve regeneration [17,18]. In this study, the quantitative comparison of both DRG outgrowth in vitro and nerve regeneration in vivo on two different polymer surface topographies (i.e., aligned and randomly oriented fiber films, but with identical material and fabrication process) clearly provides key insights into the importance of the structural cues (i.e., alignment) for promoting nerve regeneration.…”

“…The clinical "gold standard" for bridging peripheral nerve gaps is the use of autografts (typically, the sensory sural nerve). However, the use of autografts is limited by the following issues: 1) limited availability of nerves to use in the autograft [1], 2) secondary surgery, 3) lack of coaptation between the injured nerve and the nerve graft due to size/length/modality mismatch [2], and 4) functional loss, such as numbness at the donor sites [3]. Moreover, complications at the donor site such as hyperesthesia or formation of painful neuromas also have to be addressed [4,5].…”

Biodegradable Cell-Seeded Nanofiber Scaffolds for Neural Repair

“…Bini et al [166] fabricated a tubular and porous nerve guidance conduit made of PLGA (10:90) fibers using a microbraiding technique with potential application for peripheral nerve regeneration, and also investigated its degradation behavior. Swelling, a common phenomenon caused by water uptake and observed in many biodegradable nerve conduits, was not detected; maintaining a constant lumen cross section in a conduit may be advantageous for nerve regeneration.…”

Novel opportunities and challenges offered by nanobiomaterials in tissue engineering

“…The charged jet is accelerated toward the counter electrode, and it thins rapidly during this period due to droplet elongation and evaporation of the solvent until solid or wet fi bers are deposited onto a substrate, usually a planar surface, located on top of the counter electrode. Electrospinning process is economical, simple, yields continuous fi bers (while for self-assembling they are a few micrometers in length) and hollow fi bers, and is versatile enough to be applied to a variety of materials to obtain knitted structures (Bini et al 2004), aligned nanofi bers (Corey et al 2007), or core-shell structures. In electrospinning, fi bers can be spun from polymers at their molten state or organic solvents and water polymeric solutions.…”