Brazilian and European researchers have demonstrated exactly how a nanotechnology-based compound delivers an oral vaccine against hepatitis B to the immune system. When particles containing silica and an antigen combine, even though they are different sizes, they reach the intestine without being destroyed by the acidity of the digestive system.
A compound of nanostructured SBA-15 silica and HBsAg, the hepatitis B surface antigen, was submitted to different types of X-ray imaging in European laboratories.
Silica - Researchers - University - São - Paulo
The nanostructured silica was developed by researchers at the University of São Paulo's Physics Institute (IF-USP) in Brazil. The antigen was created by the Butantan Institute, which is also in São Paulo. The results are published in Scientific Reports.
The aim of the study was to understand how a 22-nanometer-sized antigen binds to silica nanotubes with a diameter of approximately 10 nanometers and a honeycomb-like structure. One nanometer (1 nm) is a billionth of a meter. Studies carried out at USP revealed the measurements of both the antigen and the silica nanotubes using small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and transmission electron microscope.
Size - Difference - Tests - Animals - Immune
"Despite the size difference, tests [in animals] produced an excellent immune response to the oral vaccine—as good as the injectable form or better," said Márcia Fantini, full professor at IF-USP.
X-ray and neutron imaging was coordinated by Heloisa Bordalo, a Brazilian researcher at the University of Copenhagen's Niels Bohr Institute in Denmark. In collaboration with other researchers in Denmark as well as colleagues in France, Germany, Sweden and Switzerland, Bordalo submitted the compound to small-angle X-ray scattering (SAXS), among other techniques.
Images - Techniques - Antigen - Nanotubes - Macropores
The three-dimensional images obtained by these techniques showed that although the antigen did not enter the nanotubes, it was retained in 50 nm macropores between the nanotubes. This protected it from the acidity of the digestive system.
(Excerpt) Read more at: phys.org