1:Biodonostia Institute; 2:Otorhinolaryngology - Head & Neck Surgery Department, Hospital Universitario Donostia, Biodonostia Health Research Institute, Donostia-San Sebastián, 20014, Spain.; 3:Head & Neck Study Group of Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), Donostia-San Sebastián, 20014, Spain.; 4:BIOMAT Research Group, Escuela de Ingeniería de Gipuzkoa, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, 20018, Spain.; 5:BCMaterials - Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, Leioa, 48940, Spain.; 6:Proteinmat Materials SL , Donostia-San Sebastián, 20018, Spain

Tympanic membrane perforations (TMP) represent a common cause of visit to the ear, nose, and throat specialist, usually due to recurrent infections or trauma. The rate of recovery depends on the TMP size and the presence of secondary infection. The current gold standard treatment (myringoplasty) presents relevant morbidity and costs. We aimed to develop and test a protein-based biomaterial to be used as a carrier in tympanic membrane (TM) regeneration. For this purpose, we designed scaffolds based on porcine gelatine and characterised them in terms of intrinsic properties (water uptake, water vapour transmission rate and degradation degree analyses), functional properties (puncture and mucoadhesion tests) and biocompatibility. The gelatine-based scaffolds showed adequate hydration and permeability properties, and did not degrade following 6-month exposure to water. The performance in the puncture and mucoadhesion tests was similar to native TM, and the scaffolds were fully biocompatible over one-week period. Encouraged by these results, we are currently conducting an in vivo study in a rat model of chronic TMP to study the integration, regeneration and functionality of the developed TM substitutes for a period of 8 weeks (N=4 per group). Outcome measures to monitor the evolution of the chronic perforations include the level of closure as measured by otoscopy and the detection of inflammatory markers in the blood at weeks 1, 4 and 8. Preliminary preclinical results will be presented at the meeting.