New polymer gel for treating blindness
doi:10.1038/nindia.2019.44 Published online 10 April 2019
Researchers have synthesised a novel temperature-sensitive polymer-based gel that can repair retinal detachments and seal breaks in the retina, a layer of light-sensitive cells on the inside back wall of the eye1. This ‘thermogel’ could be useful for treating the retinal diseases that lead to blindness.
Ageing impairs the functions of the vitreous body, a clear gel that fills the space between the lens and the retina of the eyeball. A damaged vitreous causes the retina to detach, resulting in blindness. Specific liquids and polymer gels used as alternatives to the natural vitreous are toxic.
To find a safer alternative, an international research team, including a scientist from the Vision Research Foundation in Chennai, India, prepared the thermogel by linking three different polymers: a water-absorbing polymer, a temperature-sensitive polymer, and a water-repelling and biodegradable polymer.
The researchers then tested the efficiency of the gel in replacing the natural polymer gel that forms the vitreous in the eyes. They surgically removed the natural vitreous and injected the gel into the eyes of rabbits and non-human primates.
Unlike commercial gels, which are toxic to the eyes, the new gel was non-toxic to the eyes and retained retinal structure and function six months after implantation in rabbits and up to one year in non-human primates.
After six months, the gel was able to form a vitreous-like body containing its key structural proteins such as collagen, fibrillin and vitrin. Since this gel doesn’t require removal surgery, it can reduce the healthcare costs and clinical complications associated with such surgery.
1. Liu, Z. et al. Retinal-detachment repair and vitreous-like body reformation via a thermogelling polymer endotamponade. Nat. Biomed. Eng. (2019) doi:10.1038/s41551-019-0382-7