Polyester based nerve guidance conduit design.

Nerve conduits containing highly aligned architecture that mimics native tissues are essential for efficient regeneration of nerve injuries. In this study, a biodegradable nerve conduit was constructed by converting a porous micropatterned film (PHBV-P(L-D,L)LA-PLGA) into a tube wrapping aligned electrospun fibers (PHBV-PLGA). The polymers were chosen so that the protective tube would erode slower than the fibrous core to achieve complete healing before the tube eroded. The pattern dimensions and the porosity (58.95 (%) with a maximum pore size of 4-5 microm) demonstrated that the micropatterned film would enable the migration, alignment and survival of native cells for proper regeneration. This film had sufficiently high mechanical properties (ultimate tensile strength: 3.13 MPa, Young's Modulus: 0.08 MPa) to serve as a nerve guide. Electrospun fibers, the inner part of the tubular construct, were well aligned with a fiber diameter of ca. 1.5 microm. Fiber properties were especially influenced by polymer concentration. SEM showed that the fibers were aligned parallel to the groove axis of the micropatterned film within the tube as planned considering the nerve tissue architecture. This two component nerve conduit appears to have the right organization for testing in vitro and in vivo nerve tissue engineering studies.