In vitro reconstruction of a three-dimensional middle ear mucosal organ and its in vivo transplantation.
CONCLUSIONS
These experimental findings suggest the feasibility of artificial middle ear mucosa grafting as an effective treatment for achieving mucosal regeneration after middle ear surgery.


OBJECTIVE
Postoperative mucosal regeneration of tympanic cavity and mastoid cavity is of great importance after middle ear surgery. We reconstructed in vitro a three-dimensional middle ear mucosal organ, and assessed its feasibility for regenerative medicine of middle ear-related diseases.


METHODS
Epithelial cells and fibroblasts were isolated from the middle ear mucosa of rats and propagated by subculturing. An artificial middle ear mucosal organ was reconstructed by overlaying the middle ear epithelial cells on three-dimensional lattices of a collagen gel that had been repopulated with the fibroblasts. In addition, the artificial organ was implanted in the middle ear cavity of rats.


RESULTS
The artificial middle ear mucosa consisted of the single layer of epithelial cells, the basal membrane, and the underlying connective tissue. Electron microscopy revealed the presence of tight junctions and adherence junctions on the apical side, and adhesion complexes made of desmosomes. The reconstituted mucosa expressed genes of mucin, strongly suggesting that the artificial middle ear mucosa was capable of secreting mucus proteins. The DiI-labeled artificial middle ear mucosa implanted into the middle ear cavity was well engrafted and associated with host tissues.
Wada
Kota
K
Department of Otorhinolaryngology, Jikei University School of Medicine, Tokyo, Japan. wadakota@jikei.ac.jp
Tanaka
Yasuhiro
Y
Kojima
Hiromi
H
Inamatsu
Mutsumi
M
Yoshizato
Katsutoshi
K
Moriyama
Hiroshi
H
D000818:Animals; D001187:Artificial Organs; D002455:Cell Division / Q000502:physiology; D003094:Collagen; D003470:Culture Media; D004432:Ear, Middle / Q000166:cytology*; D004847:Epithelial Cells / Q000166:cytology / Q000637:transplantation; D005347:Fibroblasts / Q000166:cytology / Q000637:transplantation; D005786:Gene Expression Regulation; D048091:Guided Tissue Regeneration / Q000379:methods*; D007633:Keratins / Q000648:ultrastructure; D008416:Mastoid / Q000166:cytology / Q000601:surgery; D008854:Microscopy, Electron; D009077:Mucins / Q000235:genetics; D009092:Mucous Membrane / Q000166:cytology* / Q000637:transplantation*; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023822:Tissue Engineering / Q000379:methods*; D016378:Tissue Transplantation / Q000379:methods*; D014433:Tympanoplasty / Q000379:methods*; D014746:Vimentin / Q000648:ultrastructure
D003470:Culture Media; D009077:Mucins; D014746:Vimentin; D007633:Keratins; D003094:Collagen