An artificial retina engineered from ancient protein heads to space

NIH supported early testing of the artificial retina. Now, scientists are testing whether manufacturing it on the International Space Station results in a viable treatment for people with blinding eye diseases. 

A plan to manufacture an artificial retina that mimics the functions of the light-sensitive tissue at the back of the eye is taking things to the next level – 260 miles above Earth. 

LambdaVision, the Farmington, Connecticut-based biotech firm that developed the artificial retina, is exploring optimizing production of the artificial retina in space. In a series of missions to the International Space Station (ISS), the company will test whether microgravity on the station provides just the right conditions for constructing the multilayered protein-based artificial retina. 

To get off the ground, LambdaVision received a $5 million commercialization award from the National Aeronautics and Space Administration (NASA), along with its partner, Space Tango, a Lexington, Kentucky based firm that provides the logistical support for space-based research.

“When gravity is nearly eliminated, so too are forces such as surface tension, sedimentation, convection driven buoyancy, all of which can interfere with the orientation and alignment important in the creation  of crystalline structures, nanoparticles, or improved uniformity in layering processes,” said Jana Stoudemire, a commercial innovation officer at Space Tango. 

“We’re building out not only the feasibility of manufacturing in orbit, but also the good manufacturing practices (GMP) capabilities that enable us to produce products in space for use in people. As in, therapies manufactured in space and returned to Earth for commercial distribution to patients,” said Stoudemire.  

Watch this video to learn more about how an artificial retina may help restore vision in patients who have lost their sight. 

“The hope is that surgically placing the artificial retina in the eye will restore vision among people with advanced-stage forms of diseases for which there is no treatment such as retinitis pigmentosa and age-related macular degeneration (AMD), a leading cause of vision loss among people age 50 and older,” said Jordan Greco, Ph.D., chief scientific officer at LambdaVision.

In a healthy eye, light from a visual scene reaches the retina where it’s converted into electrical signals by neurons called photoreceptors. Those signals are communicated to other retinal cells called bipolar and retinal ganglion cells, until they reach the optic nerve, where they travel to the brain. The brain puts the signals together to produce vision. 

The aim is for the LambdaVision artificial retina to replace the function of photoreceptors in people who’ve lost the neurons from disease-related damage. 

In 2014, the company received funding from the National Eye Institute (NEI) to test a prototype of the artificial retina in animal models. “The Small Business Technology Transfer grant is designed to support biotech companies, such as LambdaVision, as they take steps toward commercializing their innovative products,” said Paek Lee, Ph.D., program manager for small business grants at NEI. 

Recipients must be for-profit U.S. business that are at least 51% U.S.-owned by individuals and independently operated, with no more than 500 employees. Each year, approximately 40 to 50 small business grants are awarded from a total of about $25 million.

A look at the artificial retina

LambdaVision’s artificial retina relies on bacteriorhodopsin, a light-activated protein that acts as a proton pump. Bacteriorhodopsin is synthesized by halobacterium salinarum, a microorganism found in extremely salty marshes. Halobacteria are of the Archaea domain, which are among the oldest forms of life on Earth.

As its name implies, bacteriorhodopsin shares some similarities with rhodopsin, the light-activated visual pigment protein within photoreceptors. Both proteins contain retinal, a chromophore that’s key to absorbing light energy. In the case of bacteriorhodopsin, light energy is converted into metabolic energy. When light activates bacteriorhodopsin, hydrogen ions get pumped across a membrane, creating a proton gradient.

LambdaVision’s founder Robert Birge, Ph.D., distinguished chair in chemistry at the University of Connecticut, has been studying bacteriorhodopsin for over forty years and has made a career of incorporating light-activated proteins into biomolecular electronic and therapeutic applications, including the protein-based artificial retina. 

In the 1980s, Birge and many other innovators, looked to biological systems to see how their structures could inform the development of nano-sized technologies. After all, compared to relatively bulky mechanical electrical circuits, the natural world is full of nano-sized electrical circuits that have evolved over millions of years. 

In addition to being light-activated, bacteriorhodopsin’s molecular structure is highly ordered and thermally stable, adding to its potential for nanotechnology innovations from light-driven batteries to information processors and the artificial retina.

Within LambdaVision’s artificial retina, purified bacteriorhodopsin is layered onto an ion permeable membrane. The layers are repeated multiple times with the aim of absorbing enough light to generate an ion gradient that can stimulate the neural circuitry of the bipolar and retinal ganglion cells within the retina, said Greco. 

“In patients who’ve lost their vision from advanced-stage retinal diseases, the artificial retina would mimic the function of photoreceptors. Activated by light entering the eye, the artificial retina pumps protons toward the bipolar and ganglion cells. Receptors on those cells detect the protons, which triggers them to send signals to the optic nerve, where they travel to the brain,” said Nicole Wagner, Ph.D., LambdaVision’s president and chief executive officer. 

For the artificial retina to function, the bacteriorhodopsin molecular structures must be precisely oriented within each layer to create a unidirectional gradient. That exacting degree of orientation may be more easily established in microgravity, and once achieved, Greco anticipates it should persist even after the implants are exposed to gravity on Earth.

LambdaVision plans to seek Food and Drug Administration approval of the artificial retina for the indication of retinitis pigmentosa.  Collection of the preclinical data required to launch a clinical trial is still underway and have yet to be published. 

Payloads to the ISS are packed into containers roughly the size of a boot box. CubeLabs contain automated hardware, optics and imaging required for researchers on Earth to perform experiments in real time. Credit: SpaceTango

Lab-based science in space

On each mission to the ISS, Space Tango arranges for payloads containing mini laboratories called CubeLabs, one of which is dedicated to LambdaVision’s research. Space Tango’s trademarked research platform, CubeLabs are roughly the size of boot box and each contains all the automated hardware, optics and imaging required for researchers on Earth to perform iterative experiments in real-time. 

Most recently, LambdaVision’s CubeLab was one of 10 payloads launched to the ISS on February 20, 2021 aboard Northrup Grumman’s 15th commercial resupply services mission known as CRS15. 

The LambdaVision project is part of a larger endeavor spearheaded by NASA to explore the viability of commercializing low-Earth orbit to the point where it is sustainable by private industry. Microgravity occurs at altitudes of 1200 miles or less. The ISS, which orbits Earth every 90 minutes, has become a unique laboratory for microgravity research.

In June 2019 NASA opened the ISS to industry partners looking to manufacture, market and promote commercial products and services in microgravity. Aside from LambdaVision, NASA is providing seed money to six other companies to explore manufacturing products on the ISS.

With the expected phasing out of NASA funding for the ISS by 2025, companies such as Axiom Space are working on a commercial space station that would allow companies such as Space Tango to maintain an ongoing presence in low-Earth, said Stoudemire.

In addition to partnering with industry, NASA is also collaborating with the National Institutes of Health to conduct basic and translational research in microgravity to expand our understanding of diseases processes and aging. 

To learn more about research conducted on the ISS, watch this video of NIH director, Francis Collins chatting with astronaut Kate Rubins.

##

The Small Business Innovation Research (SBIR) program is a competitive awards-based funding mechanism that supports U.S.-based small businesses engaged in research and development that has the potential for commercialization. The NEI SBIR program specifically provides funding to companies developing technologies and innovations relating to blinding eye diseases, visual disorders preservation of sight, and addressing the special health problems and requirements of individuals with impaired vision.

NEI leads the federal government’s research on the visual system and eye diseases. NEI supports basic and clinical science programs to develop sight-saving treatments and address special needs of people with vision loss. For more information, visit https://www.nei.nih.gov. 

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit https://www.nih.gov/. 

NIH…Turning Discovery Into Health®