[ExI] Nanoparticle injection grants nightvision to mice.

[Stuart LaForge]

Now this technology scores really high on the H plus cool meter:  
injectable nanoparticles that allow mammals to see near infrared. The  
same wavelengths used by so-called night vision goggles only unlike  
night vision goggles, the nanoparticles work during the daytime too.  
So many applications . . .


http://www.sci-news.com/biology/mice-infrared-vision-06960.html

"Humans and other mammals are limited to seeing a range of wavelengths  
of light called visible light, which includes the wavelengths of the  
rainbow. But infrared radiation, which has a longer wavelength, is all  
around us. People, animals and objects emit infrared light as they  
give off heat, and objects can also reflect infrared light. Now a team  
of researchers from the University of Massachusetts Medical School,  
the University of Science and Technology of China and China’s Center  
for Excellence in Brain Science and Intelligence Technology has  
developed technology to give night vision to mammals. A single  
injection of nanoantennae in the mice’s eyes bestowed infrared vision  
for up to 10 weeks with minimal side effects, allowing them to see  
near-infrared light even during the day and with enough specificity to  
distinguish between different shapes.

Injectable photoreceptor-binding nanoparticles with the ability to  
convert photons from low-energy to high-energy forms allow mice to  
develop infrared vision without compromising their normal vision and  
associated behavioral responses. Image credit: Ma et al, doi:  
10.1016/j.cell.2019.01.038.
Injectable photoreceptor-binding nanoparticles with the ability to  
convert photons from low-energy to high-energy forms allow mice to  
develop infrared vision without compromising their normal vision and  
associated behavioral responses. Image credit: Ma et al, doi:  
10.1016/j.cell.2019.01.038.

The visible spectrum is the portion of the electromagnetic spectrum  
that is observed by the human eye. A typical mammalian eye will  
respond to wavelengths from about 400 to 700 nm (nanometers).

However, this is only a small percentage of the full electromagnetic  
spectrum. The detection of longer wavelength light, such as  
near-infrared (NIR) light or infrared light, is impossible.

The human eye is unable to see NIR or to project an NIR image to the  
brain without the aid of complicated and cumbersome electronic  
devices, such as night vision goggles. During the day, these goggles  
become saturated and lose their ability to function.

“The visible light that can be perceived by human’s natural vision  
occupies just a very small fraction of the electromagnetic spectrum,”  
said study co-author Dr. Tian Xue, a researcher at the University of  
Science and Technology of China.

“Electromagnetic waves longer or shorter than visible light carry lots  
of information.”

“With this research, we’ve broadly expanded the applications of our  
nanoparticle technology both in the lab and translationally. These  
nanoantennae will allow scientists to explore a number of intriguing  
questions, from how the brain interprets visual signals to helping  
treat color blindness,” said Dr. Gang Han, from the University of  
Massachusetts Medical School.

In the study, the scientists developed lectin protein conjugated  
nanoparticles that can be delivered in droplets.

These proteins guide the nanoantennae and ‘glue’ them to the outside  
of retinal photoreceptors in mice. Once anchored on the cells, these  
microscopic antennae convert NIR into visible, green light.

The green light is observed by the retinal cell and images are sent  
and interpreted by the brain as visible light. This happens without  
the aid of complicated equipment.



The researchers also developed a series of tests to verify that the  
mice treated with the nanoparticles were fully capable of perceiving  
NIR light.

They demonstrated that mice injected with these nanoantennae can not  
only perceive NIR light, but also obtain NIR pattern vision and are  
even able to differentiate between sophisticated shape patterns such  
as triangles and circles.

Treated mice were able to perceive these light patterns even in  
daylight conditions, indicating that the nanoparticles were working in  
parallel with conventional vision.

Also, thanks to the close proximity of the nanoantennae and  
photoreceptors, an exceptionally low power NIR LED lamp light is  
sufficient to activate the nanoparticles.

After two weeks, the ability wore off and the nanoparticles left no  
lingering effects to the mice or their vision.

“We believe that this research is a major advance in the field of  
biotechnology. This concept-provoking study should pave the way to  
numerous critical applications via the unique creation of mammalian  
NIR visual ability and have high translational potential,” Dr. Han said.

“Moreover, it is very likely that the sky may look very differently  
both at night and in daytime. We may have the capability to view all  
the hidden information from NIR and IR radiation in the universe which  
is invisible to our naked eyes.”

The results were published in the journal Cell.