title: Biocompatibility of "On-command" dissolvable tympanostomy tube in the rat model.
abstract: A prototype tympanostomy tube, composed of polybutyl/methyl methacrylate-co-dimethyl amino ethyl methacrylate (PBM), was tested to 1) evaluate the effect of PBM tubes on rat dermis as a corollary for biocompatibility and (2) to observe the efficacy of dissolution with isopropyl alcohol (iPrOH) and ethanol (EtOH).
  
  
  
  Original animal experiment and bench testing.
  
  
  
  A two-part study was conducted to assess biocompatible substance with inducible dissolvability as a critical characteristic for a newly engineered tympanostomy tube. First, tympanostomy tubes were inserted subcutaneously in 10 rats, which served as an animal model for biosafety, and compared to traditional tubes with respect to histologic reaction. Tissue surrounding the PBM prototype tubes was submitted for histopathology and demonstrated no tissue reactivity or signs of major inflammation. In the second part, we evaluated the dissolvability of the tube with either isopropyl alcohol, ethanol, ofloxacin, ciprodex, water, and soapy water. PBM tubes were exposed to decreasing concentrations of iPrOH and EtOH with interval qualitative assessment of dissolution.
  
  
  
  Histologic examination did not reveal pathology with PBM tubes. Concentrations of at least 50% iPrOH and EtOH dissolve PBM tubes within 48 hours, whereas concentrations of at least 75% iPrOH and EtOH were required for dissolution when exposure was limited to four 20-minute intervals.
  
  
  
  PBM is biocompatible in the rat model. Additionally, PBM demonstrates rapid dissolution upon alcohol-based stimuli, validating the proof-of-concept of dissolvable on-command or biocommandible ear tubes. Further testing of PBM is needed with a less ototoxic dissolver and in a better simulated middle ear environment before testing can be performed in humans.
  
  
  
  NA Laryngoscope, 127:956-961, 2017.
authors: Department Surgery, Division of Otolaryngology-Head and Neck Surgery, Washington, District of Columbia, U.S.A.
authors: Johnny P
authors: JP
authors: Mai
authors: George Washington University Health Science Center, Washington, District of Columbia; Sheikh Zayed Center for Pediatric Surgical Innovation, Washington, District of Columbia, U.S.A.
authors: Matthieu
authors: M
authors: Dumont
authors: Washington, District of Columbia; Department of Surgery, Division of Pediatric Otolaryngology-Head and Neck Surgery, Washington, District of Columbia, U.S.A.
authors: Christopher
authors: C
authors: Rossi
authors: George Washington University Health Science Center, Washington, District of Columbia; Sheikh Zayed Center for Pediatric Surgical Innovation, Washington, District of Columbia, U.S.A.
authors: Kevin
authors: K
authors: Cleary
authors: Department Surgery, Division of Otolaryngology-Head and Neck Surgery, Washington, District of Columbia, U.S.A.
authors: Joshua
authors: J
authors: Wiedermann
authors: Children's National Medical Center, Washington, District of Columbia; and the Department of Surgery, Division of Pediatric Otolaryngology-Head and Neck Surgery, Children's National Medical Center, Washington, District of Columbia, U.S.A.
authors: Brian K
authors: BK
authors: Reilly
mesh_terms: D019840:2-Propanol / Q000494:pharmacology; D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004432:Ear, Middle / Q000473:pathology / Q000601:surgery*; D000431:Ethanol / Q000494:pharmacology; D007150:Immunohistochemistry; D008876:Middle Ear Ventilation / Q000295:instrumentation* / Q000379:methods; D011474:Prosthesis Design; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity
chemical_list: D001672:Biocompatible Materials; D000431:Ethanol; D019840:2-Propanol
keywords: Biocommandability; dissolvable; grommet; myringotomy tube; pressure equalization tube; tympanostomy tube