Cornea from the printer
A biocompatible artificial cornea has been printed and successfully transplanted
Georgy Golovanov, Hi-tech+
Korean scientists used corneal connective tissue devoid of cells and stem cells as ink, so the transplant turned out to be biocompatible. In terms of transparency, it is not inferior to a healthy cornea.
The cornea is the outermost, thin layer covering the pupil and protecting the eye from the external environment. This is a lattice of collagen fibers or fibrils, which must be transparent in order to let in light, move with the pupil and have sufficient elasticity.
In case of serious corneal injuries, doctors recommend transplantation. However, a patient can wait in line for a transplant for five years or more. The solution could be an artificial cornea, but its modern variants made of collagen or synthetic polymers either do not take root well or do not have sufficient transparency, according to the website of Pohang University of Science & Technology (3D Printed Artificial Corneas Similar to Human Ones).
Article by Hyeonji Kim et al. Shear-induced alignment of collagen fibrils using 3D cell printing for corneal stroma tissue engineering is published in the journal Biofabrication – VM.
In order to solve this problem, the researchers applied the shear stress that occurs during 3D printing and achieved the creation of a corneal lattice. They also demonstrated that extracellular matrix-based biochernils obtained as a result of decellularization are compatible with biological tissues.
On the left – the appearance and cross–sections of the cornea obtained using three–dimensional printing and grown from stem cells on a substrate, on the right - the distribution of collagen fibers in them - VM.
During three-dimensional printing, when the ink in the printer moves through the nozzle and out of it, a friction force arises, creating a shear stress.
By regulating this tension of collagen fibers, scientists were able to achieve the creation of a functional artificial cornea with a lattice like a real one.
The transplanted artificial cornea retained its original qualities four weeks after transplantation, according to Korean scientists. They hope that their technology will give hope to many patients waiting for surgery.
For the first time, the bioprinting of the human cornea was reported by British scientists a year ago. They mixed the stem cells of the stroma of a healthy donor with the impression mass and collagen and received "biochernils", which were filled into a regular cheap 3D printer and printed lenses in the shape of a cornea. Then the cells were given time to grow.
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