Design and properties of a new braided poly lactic-co-glycolic acid catheter for peripheral nerve regeneration

Abstract

A new braided poly lactic-co-glycolic acid (PLGA) (LA : GA = 10 : 90) catheter, consisting of an outside-tube and an inside-scaffold, was designed and fabricated to guide and support peripheral nerve regeneration. According to the process of peripheral nerve regeneration, the functional division of the outside-tube and the inside-scaffold was confirmed as follows: the major function of the outside-tube was support for the space of the nerve regeneration and the needed good compression performance and the major function of the inside-scaffold was simulation of the matrix bridge in the nerve regeneration process. Therefore, the outside-tube was braided for a higher density with PLGA ply yarns and coated with chitosan; the inside-scaffold was braided for a lower density with PLGA single filaments treated by H2O2. The arrangement and number of micro-tubes were designed and theoretically calculated. In this paper, the basic thickness and density performance of the new catheter was tested first. Then, the fibroblast cytocompatibility and the fiber tensile in degradation were assessed as indications of the performance change of the unmodified and modified materials. Finally, the compression performance of the new catheter was compared with two other catheters. The results showed that the new catheter had a uniform and stable structure. The modified inside-scaffold had a higher cytocompatibility and facilitation of fibroblast growth than the unmodified one; meanwhile, it maintained enough mechanical properties to support nerve regeneration in degradation. Furthermore, the elastic recovery and compressive resistance retention respectively reached 84% and 93%, which meant excellent compression performance. In summary, the performance of this new braided PLGA catheter attained the designed targets.