Otitis media, or
ear infection, is as common in kids as scraped knees, but it's a lot more
difficult to treat, usually requiring a long course of antibiotics. Daniel
Kohane, a doctor at Boston Children’s Hospital, compared force-feeding
antibiotics to children to full-contact wrestling. So, working at the
Laboratory for Biomaterials and Drug Delivery at the Massachusetts Institute of
Technology, he developed an antibiotic-infused gel to treat and cure ear
infections with a single application.
Kohane said a
clinician can squirt the gel into the child’s ear during a single visit to the
doctor. The gel forms a hardened plug, and the active ingredients are able to
pass through the tympanic membrane, or eardrum, to treat the infection where it
is needed.
Kohane said
skeptical scientific researchers never thought it was possible to get the
antibiotic past the eardrum. But the gel contains chemical permeation
enhancers, compounds that have already received regulatory approval for other
uses. Known as CPEs, they are structurally similar to lipids or fat molecules
in the stratum corneum, the eardrum’s outermost layer. The CPEs insert
themselves into the membrane, opening up molecular pores that allow the
antibiotics to seep through.
Kohane said the
ear gel causes fewer side effects than antibiotics.
“I previously
spoke about the convenience that this gives the parents," he told VOA,
"but the other thing to understand is that current therapy is an oral
regimen of 10 days. So when you take a drug orally, the drug has to go
throughout the body to treat a really small piece of real estate inside the
head. The entire body gets exposed to antibiotic, and this leads to a number of
side effects, like diarrhea, rashes and things like that.”
Antibiotic
resistance
In addition to
side effects, there is the problem of antibiotic resistance. When a child
starts to feel better in a few days, parents may stop trying to medicate a
squirming child, creating stronger bacteria and harder-to-treat infections.
The ear gel was
tested in chinchillas, which were used because they have an ear structure and
hearing range similar to those of people. The gel dispensed high concentrations
of the antibiotic ciprofloxacin in the middle ear and completely cured ear
infections caused by Haemophilus influenzae in 10 of 10 animals. Ordinary
ciprofloxacin eardrops cured the infection in only five of eight chinchillas.
Researchers said
there were no side effects beyond a slight, temporary hearing loss, like that
caused by earwax. The problem could be solved, they said, by squirting less gel
into the ear.
An article
describing the ear gel was published in the journal Science Translational
Medicine. Kohane’s associate, Rong Yang, said she was surprised by comments
from the paper’s reviewers at the journal.
“They referred
to this technology that we developed as exciting, innovative, unique,
impressive, close to ideal, much-needed,” said Yang. Kohane added, "One reviewer asked us to
change a comma. That was the sum total of the constructive criticism.” The next
step is human clinical trials, which can’t come too soon for many parents.
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