Silk fibroin nanofiber scaffold (SFNS) as a graft material for myringoplasty- in vitro and in vivo

Tympanic membrane (TM) perforation repair or myringoplasty is one of the most common surgeries performed in ENT practice. This surgery uses graft materials such as temporalis muscle fascia, pinna cartilage, perichondrium, and even artificial materials such as silicone and polymers to restore the hearing mechanism in deaf people and stops ear discharge. Some disadvantages of this surgery include the requirement for complex microsurgical skills, high cost, graft site complications, and anesthesia-related risks. To overcome these drawbacks, a variety of bioengineered graft materials, such as polycaprolactone (PCL), silk polymers are being used. In this study, we used in vitro and in vivo investigations to assess the potential use of silk fibroin nanofiber scaffolds (SFNS) as a graft material. Cell proliferation, viability studies and DNA quantification tests were performed on rat primary TM epithelial cells and human mammary fibroblast (HMF) cells to evaluate SFNS in vitro. The results demonstrated that both rat primary TM epithelial cells and HMF cells are compatible with SFNS graft material and showed cell proliferation. The scanning electron microscopy (SEM) was used to image the rat primary TM epithelial cells on SFNS and found the cells integrated into SFNS, proving that the graft material is nontoxic. The in vivo experiments included creating TM perforations in Sprague Dawley rats and performing myringoplasty with SFNS as a graft. Five out of six rats demonstrated effective perforation healing, including evidence of neovascularization at the pars tensa, indicating that the SFNS is biocompatible and can be employed for TM perforation repair.