Mechanical properties of acellular peripheral nerve.

BACKGROUND Acellular nerve has been used in experimental models as a peripheral nerve substitute. Our objective was to determine the difference in tensile strength between fresh and chemically treated acellularized peripheral nerve. MATERIALS AND METHODS F344 rat sciatic nerves were either fresh or acellularized and tested either whole (Part A) or transected and repaired (Part B). For all constructs, the mean ultimate stress, mean ultimate strain, Young's modulus, and total mechanical work to fracture were calculated. The average ultimate strains for Groups A-1 and A-2 were 0.480 +/- 0.117 and 0.810 +/- 0.114, respectively. The Young's moduli in Groups A-1 and A-2 were 576 +/- 160 and 580 +/- 150 kPa, respectively. In Groups A-1 and A-2, the normalized work to failure was 0.35 +/- 0.14 and 1.11 +/- 0.38 N. The specimens in Group B-1 withstood an average ultimate stress of 780 +/- 280 kPa. The specimens in Group B-2 withstood an average ultimate stress of 405 +/- 20 kPa. RESULTS The average ultimate strains for Groups B-1 and B-2 were 0.319 +/- 0.087 and 0.266 +/- 0.019, respectively. The Young's moduli in Groups B-1 and B-2 were 4,030 +/- 1360 and 2,290 +/- 280 kPa, respectively. The normalized work to failure in Groups B-1 and B-2 was calculated as 0.22 +/- 0.04 and 0.11 +/- 0.02 N. CONCLUSIONS Although adequately robust for reconstructive procedures, the acellular peripheral nerve had decreased tensile strength compared with fresh nerve either when tested whole or when transected and repaired.