Biomechanical Properties Of Acellular Peripheral Nerve

Objective:Utilized Endura TEL ELF 3200 to test biomechanical properties of fresh and acellularized nerve graft treated with different methods, which to investigate the differences in biomechanical properties between fresh and acellularized nerve graft.Methods:Forty-eight sciatic nerves were harvested from 24 adult male Wistar rats of 3 months old and randomly assigned into 4 groups. Normal control group(group A),in which the nerve segments were underwent no treatment and were immersed in PBS until further use; Physically freeze-thawed method group(group B),in which the nerve segments were frozen at -196℃and then thawed at 37℃,repeated this process five times; Sondell method group(group C),in which the nerve segments were chemically extracted with the detergents of Triton X-100 and sodium deoxycholate; And improved chemical method group(group D),with the detergents of TritonX-200.Sulfobetaine-10 and Sulfobetaine-16. After the acellularization process was completed, the structural changes of nerves in each group were observed by HE staining and field emission scanning electron microscope, then tested the biomechanical properties of nerves in each group using mechanical apparatus (Endura TEC ELF 3200).Results:HE staining and field emission scanning electron microscopy showed that the effect of acellularization of improved chemical method was similar to that of traditional Sondell method and better than that of physical method, but the effect of demyelination and integrity of nerve fiber tube were better than that of traditional Sondell method and physical method; The biomechanical testing showed that the ultimate loads,ultimate stresses,and mechanical work to fracture in group B were the largest.the next were group A and group C,the least was group D,but the differences in each group had no statistical significance by statistical test(P>0.05); The ultimate strains in group A were the largest,the next were group C and group D,the least was group B,but the differences in each group had no statistical significance by statistical test(P>0.05); The tenacities,elastic modulus in group B were the largest,the next were group C and group D,the least was group A; the differences between group A and group B had statistical significance(P<0.05).while the differences in other groups had no statistical significance by statistical test(P>0.05).Conclusions:This study used acellular nerve graft as a nerve substitute, which resulted in reduced immunogenicity by acellularization and maintenance of the extracellular matrix. The acellular nerve graft was researched from histological and biomechanical properties. Compared with orther methods, the nerve graft treated by improved chemical method could remove Schwann cells, preserve neural structures well and ensure biomechanical properties of nerve graft, which could be more appropriate for use in implantation.