Patients battling glaucoma and other blinding diseases can now have hope of regaining their sight after scientists at the National Eye Institute (NEI) in the US found a way to use 3D bioprinting to create eye tissue that will help them understand the mechanisms of blinding diseases.
3D bioprinting is a new technology that gives the option of creating human organs to replace damaged ones.
This means that similar to other types of additive manufacturing, bioprinting uses a digital file as a blueprint to print an object with cells and biomaterials, creating structures that let living cells within them multiply to form a new organ.
Experts at ‘Interesting Engineering’ which is a global scientific and engineering journal explain that these organs are printed layer by layer just like any 3D printing process.
However, rather than using a CAD file, they are created using a digital model with computed tomography and MRI scans.
“Bioprinting has thus far produced an anti-bacterial tooth, an ovary, a bionic ear, elastic bones, lungs, a heart, an eye and perhaps, more impressively, human skin.
Today, bioprinters can even lay down strips of skin on an affected area. Doctors and scientists are already testing bioprinters that can create skin transplants.”
The researchers at NEI further disclose that they printed a combination of cells that form the outer blood-retina barrier— eye tissue that supports the retina's light-sensing photoreceptors.
In an official press release, they explained that the method makes it possible to research age-related macular degeneration and other degenerative retinal illnesses using a theoretically limitless supply of patient-derived tissue (AMD).
According to Dr Kapil Bharti, who heads the NEI Section on Ocular and Stem Cell Translational Research, AMD starts in the outer blood-retina barrier.
“However, mechanisms of AMD initiation and progression to advanced dry and wet stages remain poorly understood due to the lack of physiologically relevant human models."
The section head and his colleagues further disclose that they used a hydrogel to mix three immature choroidal cell types: pericytes and endothelial cells, which are important components of capillaries, and fibroblasts, which give tissues structure. The gel was then printed on a biodegradable scaffold by the scientists. The cells began to grow into a dense capillary network within days.
“On the ninth day, the researchers implanted cells from the retinal pigment epithelium (RPE). RPE is usually formed from a single layer of regular polygonal cells arranged at the outermost layer of the retina. The outer side of the RPE is connected to Bruch's membrane and the choroid, while the inner side is connected to the outer segment of photoreceptor cells and is on the other side of the scaffold.
On day 42, the printed tissue was fully developed,” the researchers' highlight.
As per tissue investigations, genetic tests, and functional analysis, the printed tissue resembled the natural outer blood-retina barrier in appearance and behaviour.
Under conditions of generated stress, printed tissue displayed early AMD characteristics, such as drusen deposits beneath the RPE, and advanced to late dry-stage AMD, where tissue deterioration was seen.
Speaking to the Nation. Africa in an exclusive interview, Mr Albert Masua who is an ophthalmologist at Kwale Eye Centre lauded the new development.
“Stem cells are the way to go in terms of cell regeneration.
This is because stem cells do not conform to one type of cell but with scientific modification then they can be altered to certain cells.
My hope is if we can have stem cells regenerate the non-regenerative type, especially the nerve cells,” he said. He, however, explained that nerve cells do not regenerate in normal situations.
“So if this can occur then we can reverse so much, especially for patients with end-stage glaucoma and optic atrophy.”
According to Kenya’s guidelines for the management of glaucoma, a disease that gradually affects the optic nerve, is the second leading cause of vision loss globally, and it continues to pose a challenge to eye health professionals, in Kenya, it is estimated that 4.3 per cent of persons aged above 50 years have the glaucoma disease.
“The blindness caused by glaucoma is irreversible. We know that if diagnosed early, and with quality care, blindness due to glaucoma can be prevented. Comprehensive glaucoma care is one of the fields in eye care that requires a lot of research to establish evidence for best practices, especially for the Africa region,” the Ministry of Health (MoH) observes.
“The development of these national glaucoma guidelines is in line with one of the items of the Big 4 National Agenda: Universal health coverage (UHC) that includes affordable quality healthcare for all. It will not be UHC without eye care and for that matter quality glaucoma care.
While much is unknown about glaucoma, especially in the African race, the guidelines will need to be reviewed from time to time to adapt to the changing trends, technology and recent scientific evidence in tackling the disease,” Dr Patrick Amoth who is the Director General for Health at MoH notes.