"We demonstrate a novel approach to reverse advanced stages of blindness using hydrogel-mediated delivery of retinal pigmented epithelium (RPE) and photoreceptors directly to the degenerated retina of blind mice. With sodium iodate (NaIO3) injections in mice, both RPE and photoreceptors degenerate, resulting in complete blindness and recapitulating the advanced retinal degeneration that is often observed in humans. We observed vision restoration only with co-transplantation of RPE and photoreceptors in a hyaluronic acid-based hydrogel, and not with transplantation of each cell type alone as determined with optokinetic head tracking and light avoidance assays. Both RPE and photoreceptors survived significantly better when co-transplanted than in their respective single cell type controls. While others have pursued transplantation of one of either RPE or photoreceptors, we demonstrate the importance of transplanting both cell types with a minimally-invasive hydrogel for vision repair in a degenerative disease model of the retina."
The experimental results show that the natural light stimulation of nanoparticles, in fact, causes the activation of retinal neurons spared from degeneration, thus mimicking the functioning of photoreceptors in healthy subjects.
Compared to other existing approaches, the new liquid nature of the prosthesis ensures fast and less traumatic surgery that consist of microinjections of nanoparticles directly under the retina, where they remain trapped and replace the degenerated photoreceptors; this method also ensures an increased effectiveness.
Botond Roska is part of our Usher 1F team working with Harvard Medical School's David Corey.
The Hungarian physician Botond Roska has set himself the goal of restoring sight to the blind. Roska has tracked down the approximately one hundred different cell types in the retina and investigated their interaction. Now the scientist is working on making these fundamental insights beneficial for patients and alleviating or curing their diseases. Roska achieved a breakthrough when he reprogrammed a cell type in the eye, enabling it to take over the function of defective light receptor cells. He was thus able to make blind retinas light-sensitive again. Clinical trials with blind people have already begun. Botond Roska has been awarded the Körber Prize for European Science 2020 for his research.
Israeli researchers are developing a medication to treat retinitis pigmentosa... by recreating a supplement derived from a natural ingredient that no longer exists in sufficient quantities.
"Since the substance has proven both safe and effective in its natural form, we are very optimistic regarding the potential of the synthetic version.
"We believe that it will serve as a basis for developing an effective drug that can save the vision of many people suffering from retinitis pigmentosa."
Gene therapy generally relies on viruses, such as adeno-associated virus (AAV), to deliver genes into a cell. In the case of CRISPR-based gene therapies, molecular scissors can then snip out a defective gene, add in a missing sequence or enact a temporary change in its expression, but the body's immune response to AAV can thwart the whole endeavor.
To overcome that obstacle, researchers at the University of Pittsburgh School of Medicine created a system that uses CRISPR in a different way. Their system briefly suppresses genes that are related to AAV antibody production so the virus can deliver its cargo unimpeded.
Cell-based therapeutics developer ReNeuron Group updated the market on its trading on Thursday, reporting that patient dosing had now started in the US in the expanded phase 2a clinical trial of its hRPC cell therapy candidate in retinitis pigmentosa (RP) patients.
"In 5 unique mouse models of RP, treatment with the AAV-NR2E3 gene by subretinal injection effectively prevented the further development of multiple genetically diverse IRDs by protecting photoreceptors from further damage after disease onset. The five RP models tested were rd1 (PDE6β associated RP), Rho-/- and RhoP23H (both Rhodopsin associated RP), rd16 (Leber Congenital Amaurosis) and rd7 (Enhanced S-cone Syndrome). The study, published in Nature Gene Therapy, demonstrates the potency of a novel modifier gene therapy to elicit broad-spectrum therapeutic benefits in early and intermediate stages of RP."
"A new study published in the journal Nature Nanotechnology identifies a new potential way to restore vision in individuals with retinal degeneration, with a single injection of nanoparticles creating a working artificial retina and restoring vision in blind rodents."
"Our study suggests that the TNFα blockade could be a successful therapeutic approach to increase photoreceptor survival during the progression of RP. Further studies are needed to characterize its effect along the progression of the disease."
"In many cases of blindness, ganglion cells, the retinal output, remain functional. A promising strategy to restore vision is to express optogenetic proteins in ganglion cells. ...Using a combination of data analysis and modeling based on mouse and non-human primate retina recordings, we show that the acuity expected with this therapy could be above the level of legal blindness."