Scientists build 3D bio-engineered cornea

University scientists have succeeded in producing a prototype 3D bio-engineered cornea (pictured) as a potential surgical replacement for patients suffering diminished vision and even blindness.

A research team led by the University of Sydney’s Professor Gerard Sutton, with researchers from the University of Wollongong (UOW) has produced a prototype with the structural strength that has eluded similar attempts.

Their ultimate aim is to develop a viable system that can underpin the launch of a commercial production entity.

Director of the UOW Intelligent Polymer Research Institute (IPRI) Professor Gordon Wallace said: “We’ve hand-assembled a cornea in the lab…the breakthrough was assembling the stroma (the strength component of the structure) with aligned collagen fibrils and living cells.”

About 2,000 corneal transplants are performed in Australia each year to treat eye disease that cause the cornea to become cloudy, lose transparency or change shape, leading to blindness.

Used for conditions which include bullous keratopathy, Fuchs’ endothelial dystrophy and keratoconus, as well as eye trauma, demand for that donor tissue is now exceeding supply, with fewer than 1,500 donors in Australia in 2022.

Professor Wallace said: “Australia doesn’t do too badly, but there is a need to make sure we can generate more cornea if we are to keep up with demand – especially in developing countries.”

The researchers used a 3D bio-printing process that builds layer by layer, using a digital file as a blueprint rather than traditional fabrication. The cornea build starts with collagen molecules in a solution.

“We then apply an electric field that causes those molecules to assemble into aligned collagen fibrils to replicate that complex structure that we find naturally in the stroma.

“The process introduces living cells, so of course that means you need materials to accommodate and protect those cells to make sure they survive and develop.

“We work closely with the NSW Organ and Tissue Donation Service, and we estimate the bio-engineering process will allow us to generate at least 30 bio-engineered corneas from one donated cornea.”

The hand-assembled cornea produced on the lab bench at IPRI has taken more than three years to design and develop.

The middle layer of the cornea, the stroma, provides structural stability and durability.

Professor Wallace said: “The stroma was always going to be one of the main challenges to ensure it maintains the cornea’s exquisite shape for clear sight, and we also need to ensure it can withstand the suturing process during transplants.”

Rejection of donor tissue can cause a human cornea transplant to fail, however, bioengineered cornea can be modified to be less immunogenic by removing or modifying certain cell surface markers that trigger immune responses.

Picture: University of Sydney