A new vaccine-delivery patch based on hundreds of microscopic
needles that dissolve into the skin could allow persons without
medical training to painlessly administer vaccines — while
providing improved immunization against diseases such as
influenza.
Patches containing micron-scale needles that carry vaccine
with them as they dissolve into the skin could simplify
immunization programs by eliminating the use of hypodermic
needles — and their “sharps” disposal and re-use concerns.
Applied easily to the skin, the microneedle patches could allow
self-administration of vaccine during pandemics and simplify
large-scale immunization programs in developing nations.
Details of the dissolving microneedle patches and immunization
benefits observed in experimental mice were reported July 18th in
the advance online publication of the journal
Nature Medicine
. Conducted by researchers from Emory University and the Georgia
Institute of Technology, the study is believed to be the first to
evaluate the immunization benefits of dissolving microneedles.
The research was supported by the National Institutes of Health
(NIH).
“In this study, we have shown that a dissolving microneedle
patch can vaccinate against influenza at least as well, and
probably better than, a traditional hypodermic needle,” said Mark
Prausnitz, a professor in the Georgia Tech School of Chemical and
Biomolecular Engineering.
Just 650 microns in length and assembled into an array of 100
needles for the mouse study, the dissolving microneedles
penetrate the outer layers of skin. Beyond their other
advantages, the dissolving microneedles appear to provide
improved immunity to influenza when compared to vaccination with
hypodermic needles.
“The skin is a particularly attractive site for immunization
because it contains an abundance of the types of cells that are
important in generating immune responses to vaccines,” said
Richard Compans, professor of microbiology and immunology at
Emory University School of Medicine.
In the study, one group of mice received the influenza vaccine
using traditional hypodermic needles injecting into muscle;
another group received the vaccine through dissolving
microneedles applied to the skin, while a control group had
microneedle patches containing no vaccine applied to their skin.
When infected with influenza virus 30 days later, both groups
that had received the vaccine remained healthy while mice in the
control group contracted the disease and died.
Three months after vaccination, the researchers also exposed a
different group of immunized mice to flu virus and found that
animals vaccinated with microneedles appeared to have a better
“recall” response to the virus and thus were able to clear the
virus from their lungs more effectively than those that received
vaccine with hypodermic needles.
“Another advantage of these microneedles is that the vaccine
is present as a dry formulation, which will enhance its stability
during distribution and storage,” said Ioanna Skountzou, an Emory
University assistant professor.
Pressed into the skin, the microneedles quickly dissolve in
bodily fluids, leaving only the water-soluble backing. The
backing can be discarded because it no longer contains any
sharps.
“We envision people getting the patch in the mail or at a
pharmacy and then self administering it at home,” said Sean
Sullivan, the studys lead author from Georgia Tech. “Because the
microneedles on the patch dissolve away into the skin, there
would be no dangerous sharp needles left over.”
The microneedle arrays were made from a polymer material,
poly-vinyl pyrrolidone, that has been shown to be safe for use in
the body. Freeze-dried vaccine was mixed with the
vinyl-pyrrolidone monomer before being placed into microneedle
molds and polymerized at room temperature using ultraviolet
light.
In many parts of the world, poor medical infrastructure leads
to the re-use of hypodermic needles, contributing to the spread
of diseases such as HIV and hepatitis B. Dissolving microneedle
patches would eliminate re-use while allowing vaccination to be
done by personnel with minimal training.
Though the study examined only the administration of flu
vaccine with the dissolving microneedles, the technique should be
useful for other immunizations. If mass-produced, the microneedle
patches are expected to cost about the same as conventional
needle-and-syringe techniques, and may lower the overall cost of
immunization programs by reducing personnel costs and waste
disposal requirements, Prausnitz said.
Before dissolving microneedles can be made widely available,
however, clinical studies will have to be done to assure safety
and effectiveness. Other vaccine formulation techniques may also
be studied, and researchers will want to better understand why
vaccine delivery with dissolving microneedles has been shown to
provide better protection.
Beyond those already mentioned, the study involved Jeong-Woo
Lee, Vladimir Zarnitsyn, Seong-O Choi and Niren Murthy from
Georgia Tech, and Dimitrios Koutsonanos and Maria del Pilar
Martin from Emory University.
“The dissolving microneedle patch could open up many new doors
for immunization programs by eliminating the need for trained
personnel to carry out the vaccination,” Prausnitz said. “This
approach could make a significant impact because it could enable
self-administration as well as simplify vaccination programs in
schools and assisted living facilities.”
Research News & Publications Office
Georgia Institute of Technology
75 Fifth Street, N.W., Suite 314
Atlanta, Georgia 30308 USA
Media Relations Contacts
: John Toon, Georgia Tech (404-894-6986) (
jtoon@gatech.edu
), Holly Korschun, Emory University (404-727-3990) (
hkorsch@emory.edu
) or Abby Vogel Robinson, Georgia Tech (404-385-3364) (
abby@innovate.gatech.edu
).
Writer
: John Toon
