Comparison of porcine acellular dermis and dura mater as natural scaffolds for bioengineering tympanic membranes.

Tympanic membrane (TM) perforation is a frequent cause of conductive hearing loss. The most popular surgical repair is autografting with temporalis fascia, although some disadvantages have been found with this method. Whether xenogeneous grafts produced by a tissue engineering approach could be used is unclear. The purpose of this study was to evaluate the possibility of bioengineering TM using porcine acellular dermis and dura mater with TM fibroblasts and to compare the effects of these two natural scaffolds. Both of the materials were prepared by sequentially using Triton X-100, nuclease solution, and freeze-drying technique. Histologically, both had porous structures without any cellular components. After seeding with TM fibroblasts isolated from guinea pigs, it was found that both of the materials could be used as scaffolds for bioengineering TM in vitro. In the in vivo study, chronic TM perforation models were successfully established in guinea pigs. From gross and histological examinations, most of TM perforations were healed after grafting these two bioengineered TMs using an underlay technique. Furthermore, auditory brainstem response audiometry was applied to determine the auditory threshold in each group. Results showed that hearing in the dura mater group seemed to undergo faster recovery in the early stage but in the end, no differences were found between the two groups. Two kinds of materials without cell seeding were used as controls. Porcine acellular dermis and dura mater are suitable scaffolds for bioengineering TMs.