In situ tissue engineering with synthetic self-assembling peptide nanofiber scaffolds, PuraMatrix, for mucosal regeneration in the rat middle-ear

Abstract

Middle-ear mucosa maintains middle-ear pressure. However, the majority of surgical cases exhibit inadequate middle-ear mucosal regeneration, and mucosal transplantation is necessary in such cases. The aim of the present study was to assess the feasibility of transplantation of isolated mucosal cells encapsulated within synthetic self-assembling peptide nanofiber scaffolds using PuraMatrix, which has been successfully used as scaffolding in tissue engineering, for the repair of damaged middle-ear. Middle-ear bullae with mucosa were removed from Sprague Dawley (SD) transgenic rats, transfected with enhanced green fluorescent protein (EGFP) transgene and excised into small pieces, then cultured up to the third passage. After surgical elimination of middle-ear mucosa in SD recipient rats, donor cells were encapsulated within PuraMatrix and transplanted into these immunosuppressed rats. Primary cultured cells were positive for pancytokeratin but not for vimentin, and retained the character of middle-ear epithelial cells. A high proportion of EGFP-expressing cells were found in the recipient middle-ear after transplantation with PuraMatrix, but not without PuraMatrix. These cells retained normal morphology and function, as confirmed by histological examination, immunohistochemistry, and electron microscopy, and multiplied to form new epithelial and subepithelial layers together with basement membrane. The present study demonstrated the feasibility of transplantation of cultured middle-ear mucosal epithelial cells encapsulated within PuraMatrix for regeneration of surgically eliminated mucosa of the middle-ear in SD rats.

Influence of continuous negative pressure in the rat middle ear

“…Immunohistochemistry was performed with the indirect enzyme‐labelled antibody method as described previously . The sections were deparaffinized with toluene and rehydrated with serially graded ethanol solutions and treated with 0.2% TritonX‐100 (Sigma) in PBS.…”

Self‐assembling peptide nanofiber hydrogels in tissue engineering and regenerative medicine: Progress, design guidelines, and applications

“…Insufficient gas exchange in the mastoid mucosa often results in retraction of the tympanic membrane, causing recurrence of otitis media or hearing loss. Akiyama et al isolated mucosal cells from Sprague Dawley transgenic rats, transfected with enhanced green fluorescent protein (EGFP), encapsulated them within the Ac‐(RADA) 4 ‐CONH 2 self‐assembling peptide hydrogel, and transplanted the tissue culture into immunosuppressed rats which had undergone surgical removal of their middle‐ear mucosa . The authors found a significant number of EGFP‐expressing cells in the recipient middle‐ear after transplantation compared with the control (that is, donor cells in culture medium transplanted by injection).…”

Applications of self-assembling peptide scaffolds in regenerative medicine: the way to the clinic

“…Here, mucosal epithelial cells encapsulated in peptide matrix regenerated the damaged mucosa in the middle ear of Sprague Dawley rats. 66 Very recently Uzunalli and coworkers demonstrated that PAs functionalized with YIGSR and RGD induced corneal stroma regeneration in rabbit models. 67 …”