Biomaterials: Cell injection techniques can be used to treat visual impairments.

August 15, 2020 /--- In a recent study, engineering researchers at the University of Toronto developed a new method of injecting healthy cells into damaged eyes that could provide new treatments for vision loss that is currently incurable.
Around the world, thousands of people experience vision loss due to age-related macular degeneration (AMD) or pigmented retinitis, both of which are caused by the death of retinal cells in the back of the eye.
(Photo Source: www.pixabay.com) "The cells responsible for vision are photosensic cells that are closely related to another cell called retinal pigment epithelial cells (RPE)," said the authors, Professor Molly Shoichet. "In AMD, RPE first dies and then causes photosensome death.
have conducted experiments based on treatments that inject healthy photoreceptic or RPE cells into the eye to replace dead cells.
but integrating new cells into existing tissues is a major challenge, as most injected cells eventually die.
Shoichet and her team used an engineered biomass called hydrogels to promote the survival of newly injected cells after transplantation.
early in the injection, hydrogels ensure a uniform distribution of cells, reduce inflammation and promote tissue healing.
, they degrade naturally, leaving healthy cells.
in 2015, the team used hydrogels to inject healthy photoresponsive cells into the damaged retina of mouse models.
although the team observed some vision repair, the benefits were limited, so they began to think more carefully about the relationship between RPE cells and sensors.
Shoichet said: "RPE and sensory cells are thought to be the same functional unit, and if one cell dies, the other dies.
we wanted to know if the joint delivery of the two cells would have a greater impact on vision recovery.
like photoresocytors, many groups have tried to implant RPE cells on their own, but no one has integrated the two cell types into a single treatment.
Shoichet said: "Other researchers usually inject photoresponsive cells into a salt solution, which usually causes cells to gather together or surgically implant the layer of RPE cells that normally grow on polymer membranes.
Our hydrogels are strong enough to ensure that both cells are well distributed in syringes, but they also have important shearing and thinning properties that make it easy to inject with the very fine needles needed for this operation," Shoichet added.
team tested the method in amD's mouse model.
a recent paper published in the journal Biomaterials, they reported that mice who received co-injections regained 10 percent of their normal vision.
mice that received two cell types alone showed little improvement.
mice who received co-injections were also more active in darkrooms than bright mice, suggesting that these nocturnal animals were able to distinguish light.
(bioon.com) Source: Researchers develop cell injection type that help reverse vision loss Original source: Nikolaos Mitrousis et al, Hydrogel-mediated co-transformation of the retinal pigmented epithelium and photoreceptors restores vision in an animal model of retinal degeneration, Biomaterials (2020). DOI: 10.1016/j.biomaterials.2020.120233.