March 9

High-Pressure Spray Delivers Vaccines Directly into Cheek

As good chefs stress, presentation matters. The same holds true for vaccinemakers, who know that how you deliver the ingredients powerfully affects potency. Now, researchers have devised a gel pill that can painlessly spray vaccine into the cheek and reach cells in the underlying tissue, potentially triggering what’s known as a mucosal immune response. This, in turn, might help thwart infections with pathogens like HIV, human papillomavirus, influenza, and gonococci that enter the body through the mouth, nose, or genitals.

Unlike injected vaccines, administering this “microjet vaccination” requires no particular skill. The researchers also contend that the capsule-shaped device, which they call MucoJet, triggers unique immune responses that neither oral nor injected vaccines can produce. “We can actually reach immune cells in the oral cavity,” says team member Kiana Aran, a bioengineer at the Keck Graduate Institute in Claremont, California.

The MucoJet capsule holds about five drops of water in an outer compartment. An interior compartment has two reservoirs separated by a membrane. One contains the vaccine—for their tests, the researchers used a liquid version of ovalbumin, a constituent of egg whites. The other contains powdered citric acid and sodium bicarbonate. When a person clicks the exterior and interior compartments together before putting the MucoJet in the mouth, water penetrates the reservoir holding the citric acid and sodium bicarbonate, creating carbon dioxide—a familiar high school chemistry experiment. One minute later, the bubbly gas buildup busts the membrane and propels a piston into the chamber that holds the protein, which then sprays out a nozzle at one end of the capsule. (FluMist, an influenza vaccine delivered by a squirt into the nose, does not rely on the force of the spray to penetrate tissue.)

Source: Science (link opens in a new window)

Health Care
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