Development of a novel biodegradable drug-eluting Ventilation tube for chronic otitis media with effusion


  • This study was funded by National Research Foundation Singapore Proof-of-Concept Research Grant (NRF2009NRF-POC002-103). The authors have no other funding, financial relationships, or conflicts of interest to disclose.

Send correspondence to Lynne Hsueh Yee Lim, Department of Otolaryngology–Head and Neck Surgery, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228. E-mail:



To develop a novel drug-eluting biodegradable ventilation tube (VT), to evaluate in vitro sustained release and antibacterial adherence of ofloxacin-loaded biodegradable VT on Pseudomonas aeruginosa, and to evaluate in vivo biodegradation of VT in guinea pig ears.

Study Design

A randomized animal study.


In vitro drug release and degradation of ofloxacin-loaded VT were studied in water for 3 months. Bacterial adherence was evaluated by inoculating the VT with P aeruginosa suspension for 6 days. Scanning electron microscopy (SEM) was used for morphologic analysis. Guinea pigs were assigned to three groups: commercial Mini Shah VT, biodegradable unloaded VT, and biodegradable ofloxacin-loaded VT. Myringotomy and VT insertion were performed. SEM of VTs and histology were performed at 2, 4, 10, and 18 weeks.


A total of 81.7% of ofloxacin in VT was eluted over 3 months. Biodegradable VTs had smoother surfaces and less bacteria adherence compared to Mini Shah VTs. VTs with ofloxacin had the least bacteria adherence. VTs resulted in neither inflammation nor otorrhea 18 weeks postinsertion in guinea pigs. Histology showed the new VTs were biocompatible. The VTs were still functioning and patent after 18 weeks postinsertion but had started degrading.


The first novel biodegradable ofloxacin-loaded VT with sustainable drug release technology and antibacterial adherence property was studied. Patency beyond 4.5 months allowed an adequate period of ventilation. The complete degradation of the VT warrants further studies to evaluate the duration of VT resorption in situ and healing of the ear drum.