The body is aging unevenly. The first candidates for failure are the organs most necessary for life вЂ” eyes, teeth, and the brain. Losing their performance, they also cause a chain reaction of deterioration in the functions of other organs, which could serve for many more years. But, fortunately, having restored their work, it is possible to reverse some processes.
For example, photosensitive eye receptor proteins wear out retinal cells with every new quantum of light that is taken. But recent developments in the field of nanotechnology clearly show that the aged retina can be restored.
The research was carried out by a collaboration of scientists from the Center for Synaptic Neuroscience and Technology of Italy (Center for Synaptic Neuroscience and Technology at the Center for Nano Science and Technology) with colleagues from the Universities of Pisa, Milan, and Granada. Specialists from hospitals in Genoa, Negara, and Mantua were also involved.
Any receptor in our body that receives a particular signal and then sends it on a journey through the nervous system is a transformed neuron that has specific mechanisms for the perception of those same signals. But the task for all receptors is the same вЂ” to turn the energy of the stimulus, whether it is pressure on the skin or a photon of light, into an electrical signal that is understandable to the brain.
In the case of the retina, the process of converting the signal in the receptor wears out the photosensitive proteins located on the surface of the retinal neurons. Therefore, when the resource of the receptor protein is exhausted, the neuron still continues to live, although it becomes useless in terms of the perception of light. The nanoparticles created by scientists replace receptors that have collapsed over time, returning the meaning of life to retinal neurons.
Just one microinjection into the eye in the space in front of the retina вЂ” and vision returns to the blind rat.
Nanoparticles are located on retinal neurons that have already outlived and they again begin to show electrical activity in response to light. In this case, the вЂњintrudersвЂќ do not cause inflammation, as they have high biocompatibility.
Judging by the behavior of rats, animals after only one such microinjection began to see absolutely normal.
To make sure of this, scientists studied the brain activity of the roaring rodents. After the injection of nanoparticles, the activity of the visual cortex in previously blind rats became the same as in young and healthy sighted relatives. And this effect lasted up to eight months.
Nanoparticles are called P3HT-NPs. Having a diameter of 300 nanometers, they cannot penetrate the neuron itself and therefore remain in the extracellular space, that is, on the surface of nerve cells. In fact, they become the вЂњprosthesisвЂќ of photosensitive receptors.
At the same time, they can be distributed over the entire surface of the retina and, in contrast to existing retinal prostheses, can restore not a small area, but the entire organ.
вЂњThis is the simplest surgical procedure compared to implanting a retinal prosthesis. Nanoparticles potentially restore the entire field of view, which opens up a whole new path for the clinical use of P3HT-NPS polymer nanoparticles in cases of degenerative blindness,вЂќ summarizes leading specialist Mattia Brahmin.
An animal study confirmed the efficacy and safety of the new approach. And while far from human experiments so far, the results are very promising.
If the new method is introduced into clinical practice, the treatment of age-related eye diseases in the future will become much simpler and more reliable.