Middle ear ventilation tube (MEVT) therapy is one of the most commonly performed pediatric surgical procedures in the United States[1]. Associated problems with this procedure are bacterial infection, recurrent bleeding, prolonged ventilation due to unpredictable extrusion of the tube, and persistent perforation of the tympanic membrane[2]. To address these drawbacks, this research investigated the performance of MEVTs constructed from three resorbable polymers: Glyosilâ„¢, polylactic acid (PLA), and poly(lactic-co-glycolic acid) (PLGA). These polymers were cast into grommet-style MEVTs using custom-fabricated molds. The addition of silver antimicrobials, in the form of silver salt (AgNO3) and silver nanoparticles, to the tubes was investigated as a means to control infection at the site of implantation and reduce inflammation. In vitro studies indicate tubes containing silver exhibit a zone of inhibition when challenged with Pseudomonas chlororaphis O6. Host response and inflammation were characterized by tube implantation into tympanic membranes of chinchillas. The release of antimicrobials as the tubes degrade, in addition to possible intrinsic bacteriostatic properties of the selected biopolymers[2, 4], present a two-tiered defense against infection.

1. Kay, D.J., M. Nelson, and R.M. Rosenfeld, Meta-analysis of tympanostomy tube sequelae. Otolaryngology-Head and Neck Surgery, 2001. 124(4): p. 374-380.

2. Ludwick, J.J., et al., The bacteriostatic properties of ear tubes made of absorbable polylactic acid. International Journal of Pediatric Otorhinolaryngology, 2006. 70(3): p. 407-410.

3. Park, A.H., et al., Crosslinked hydrogels for tympanic membrane repair. Otolaryngology-Head and Neck Surgery, 2006. 135(6): p. 877-883.

4. Magnani, A., et al., In vitro study of blood-contacting properties and effect on bacterial adhesion of a polymeric surface with immobilized heparin and sulphated hyaluronic acid. Journal of Biomaterials Science-Polymer Edition, 2000. 11(8): p. 801-815.