A Novel Internal Fixator Device for Peripheral Nerve Regeneration

Abstract

Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension-traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration.

Recycle the dental fairy’s package: overview of dental pulp stem cells

“…The different cells in different surrounding materials are able to regulate self-gene expressions and secrete new ECM which will lead the other cells fate determination [ 45 ]. A well-designed device also has a similar function, for example, a novel, modular nerve-lengthening device with scaffold giving the imposition of moderate tensile for axonal outgrowth [ 8 ]. More and more studies seek to investigate the biological effects of the properties of biomaterials in TE, which is called material biology; it is a new concept draws from material science [ 45 ].…”

Photocrosslinkable Gelatin/Tropoelastin Hydrogel Adhesives for Peripheral Nerve Repair

“…3,4 However, the use of nylon or polypropylene sutures for nerve anastomosis may further damage the injured tissue resulting in increased tension, inflammation, and the development of a foreign body response (FBR). [3][4][5] In particular, excess tension in neural tissues has been associated with reduced angiogenesis, which is essential for the promotion of tissue remodeling and axonal regeneration. 6 Several sutureless interventions have been proposed, including tissue laser welding (LTW), 7,8 photochemical bonding (PTB), 9,10 as well as the use of bioadhesives.…”

Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts

“…Direct anastomosis of the transected nerve is the optimal method of nerve repair when there is low tension at the coaptation site[2526]. However, if the gap between the nerve ends is too large, a graft is needed to bridge the gap and guide the new axonal lateral buds towards the distal nerve stump, and prevent neuroma formation[2728].…”