Antibiotic-Free Treatment and Prophylaxis of Otitis Media
Otitis
media (OM) is the most commonly diagnosed pediatric disease and the #1 reason
for antimicrobial prescription to US children. Moreover, 62% of children with
OM demonstrate viral infections in their middle ear, to which antibiotics are
ineffective but prescribed nonetheless. The wide spread use of systemic
antibiotics against a disease of such high prevalence and recurrence is
believed to breed antibiotic resistance. To avoid systemic antibiotic exposure,
we have developed a platform that can non-invasively overcome the impermeable
barrier of the tympanic membrane (TM) and sustainably deliver antibiotics
directly to the middle ear. The current application attempts to completely
eliminate antibiotic usage in this prevalent childhood disease and to mitigate
antibiotic resistance by using a stand-alone therapy that treats bacterial and
viral infections.
I
propose a therapeutic system that continuously generates hypohalites in situ,
mimicking the vanadium haloperoxidase of seaweeds, using vanadium pentoxide
nanowires (V2O5-NW). V2O5-NW catalyzes oxidation of halides to hypohalites
using hydrogen peroxide (H2O2). Compared to haloperoxidase, V2O5-NW has better
stability, high reactivity with H2O2 at very low concentration (>100nM), and
scalability for industrial production. Unlike other inorganic catalysts,
V2O5-NW performs well under physiological conditions (no need for organic
solvents, or extreme temperature or pH).
Given
the paucity of biomedical experience with hypohalites, studies of
biocompatibility, toxicity, and biodistribution (especially across the round
window, and into the inner ear) will be important. We note that vanadium is
present in many foods, and hypochlorite ion is generated by human
myeloperoxidase during the oxidative burst of activated neutrophils. Damage to
hair cells by reactive oxygen species comparable to hypochlorite has been
reported at much higher concentrations (1-10 mM) than I intend to use.