Piezoelectric bilayer fibrous conduit with gellan/curcumin encapsulated alginate infilling for promotion of sciatic nerve regeneration in the rat models

The peripheral nerve regeneration has a limited innate capacity for self-repair and thus it urgently necessitates designing a smart nerve guidance conduit. Considering the electrophysiological features of nerve tissues, a piezoelectric bilayer fibrous conduit filled with drug-encapsulated gellan was developed in this study and its ability to promote neural growth was assessed in vivo. To fabricate such conduit, bilayer fibrous mats were prepared from poly ε-caprolactone/BaTiO₃ and poly-L-lactic acid -chitosan-gelatin-polyaniline/graphene via an electrospinning process. After rolling the fibrous mat, the inside of the hollow conduit was filled with gellan containing Curcumin-loaded alginate (Alg) particles. All intermediate and final products were characterized using various analytical techniques. Encapsulation of Curcumin into the Alg particles and loaded in the gellan could effectively enhance sustained release of drug during the healing process, following Higuchi model. Four weeks post-surgery, such an engineered conduit revealed much better nerve regeneration results than the control group and showed desirable outcomes in terms of sciatic function indices and formation of the perineurium as well as axon number. Such developed conduit has a high potency to repair the injured nerve tissue due to their capacity to sustain the release of drugs over a long period and transfer self-stimulated electrical signals between cells. The in vivo assay revealed the feasibility of exploiting such conduit in nerve tissue engineering.