Nanoemulsions are non-toxic lipid droplets approved for human consumption and common food substances that are defined as 'Generally Recognized as Safe' (GRAS) by the FDA. But they also can be used for medical applications. Researchers at the University of Michigan have developed nasal nanoemulsion vaccines for influenza which were successfully tested in animals in 2003. Now, the same team has shown that nanoemulsion vaccines are effective against smallpox and HIV -- at least for mice. The scientists are using an oil-based emulsion placed in the nose instead of needles. It should take years before this technique could be approved for human usage, but it really looks promising. But read more...
You can see above how nanoemulsion particles enhance the immune response system. "Nanoemulsion particles lyse virus and incorporate viral antigens into their structure. The particles are then rapidly taken up by antigen presenting dendritic cells to enhance presentation to helper T-cells." (Credit: NanoBio Corporation). Please note that "lysis refers to the death of a cell by breaking of the cellular membrane" (Credit: Lysis page on Wikipedia).
These research projects have been led by James Baker Jr., director of the Michigan Nanotechnology Institute for Medicine and Biological Sciences (M-NIMBS) ans some members of his team including Anna Bielinska, a Research Assistant Professor. For more information about this specific project, please read the Nanoemulsions page at M-NIMBS.
Here is a more detailed explanation of how nanoemulsions work. "The surface tension of the nanoparticles disrupts membranes and destroys microbes but does not harm most human cells due to their location within body tissues. Nanoemulsion vaccines are highly effective at penetrating the mucous membranes in the nose and initiating strong and protective types of immune response, Baker says. U-M researchers are also exploring nasal nanoemulsion vaccines to protect against bioterrorism agents and hepatitis B."
The smallpox results could lead to an effective human vaccine against smallpox that is safer than the present live-vaccinia virus vaccine. "When the mice were exposed to live vaccinia virus to test the vaccine’s protective effect, all of them survived, while none of the unvaccinated control mice did. The researchers conclude that the nanoemulsion vaccinia vaccine offers protection equal to that of the existing vaccine, without the risk of using a live virus or the need for an inflammatory adjuvant such as alum hydroxide."
Regarding a possible protection about HIV, the researchers said that "the HIV nanoemulsion vaccine tested in the noses of mice in the study represents 'a different approach in the way it produces immunity and the type of immunity produced.' Vaccines administered in the nose are also able to induce mucosal immunity in the genital mucosa. Evidence is growing that HIV virus can infect the mucosal immune system. 'Therefore, developing mucosal immunity may be very important for protection against HIV,' added Baker."
The study about a nanoemulsion vaccine protecting from smallpox has been published in Clinical and Vaccine Immunology under the name "A Novel, Killed-Virus Nasal Vaccinia Virus Vaccine" (February 2008, p. 348-358, Vol. 15, No. 2). Here is a link to the abstract.
The other study, about a vaccine showing immunity against HIV, has been published in AIDS Research and Human Retroviruses under the name "Nasal Immunization with a Recombinant HIV gp120 and Nanoemulsion Adjuvant Produces Th1 Polarized Responses and Neutralizing Antibodies to Primary HIV Type 1 Isolates" (Volume 24, Number 2, Pages 271-281, February 2008). Here are two links to the abstract and to the full paper (PDF format, 11 pages, 217 KB).
Finally, this technology about nanoemulsion vaccines is licensed to NanoBio Corporation, "an Ann Arbor-based biotech company which Baker founded in 2000 and in which he has a financial interest." Here are some other sources of information from NanoBio Corporation.
- their latest news release, news release named "Nasal Vaccine for Smallpox Confers High Levels of Immunity without Safety Risks" (February 26, 2008)
- a page about how their NanoStat technology works
- and a page about Mucosal-Vaccines, from which the above illustration has been picked
Sources: University of Michigan Health System news release, February 26, 2008; and various websites
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