Fabrication and optimization of multilayered composite scaffold made of sulfated alginate-based nanofiber/decellularized Wharton's jelly ECM for tympanic membrane tissue engineering

In this study, we fabricated a novel multilayer polyvinyl alcohol (PVA)/alginate sulfate (ALG-S) nanofiber/ decellularized Wharton's Jelly ECM (d-ECM) composite for tympanic membrane perforations (TMPs) tissue engineering (TE). Initially, electrospun PVA/ALG-S scaffolds with different blend ratios were fabricated. The influence of ALG-S ratio on surface morphology, mechanical, physical and biological properties of the nanofibers was studied. Secondly, 3-layer composites were developed as a combination of PVA/ALG-S nanofibers and dECM to take synergic advantages of electrospun mats and d-ECM. As part of the evaluation of the effects of dECM incorporation, the composite's mechanical properties, in vitro degradation, swelling ratio, and biological activities were assessed. The MTT assay showed that PVA/ALG-S nanofibers with 50:50 ratio provided a more desirable environment to support cell growth. A composite containing 25 mg/cm2 d-ECM was determined as the optimal composite through MTT assay, and this composite was used for animal studies inducing TMP regeneration. According to the in vivo studies, the optimal composite not only stimulated the healing of TMPs but also shortened the healing period. These results suggest that a multilayer nanofiber/hydrogel composite could be a potential platform for regenerating TMPs.