Cow cartilage used in 3D bioprinting bid to create tissue patches
Strands of cow cartilage have been used instead of ink in a printing process that may one day churn out patches for worn joints.
Researchers grew cartilage cells in thin tubes three to five hundredths of an inch in diameter made from an algae extract.
Once removed from the tubes, the cartilage strands were used for 3D bioprinting.
Squeezed through a specially designed nozzle, the strands can be laid down in rows in any desired pattern.
After about half an hour, the "printed" cartilage patch stuck together well enough to be moved to a laboratory dish.
Eventually the strands fully attached and fused together.
Lead scientist Dr Ibrahim Ozbolat, from Pennsylvania State University in the US, said: "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches.
"Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."
Cartilage is a good tissue for bioprinting because it consists of only one cell type and contains no blood vessels.
It is also a tissue that cannot self-repair. Once cartilage is damaged, it stays damaged.
Previous attempts at growing cartilage have embedded cells in a "scaffold" of hydrogel, a jelly-like plastic material.
Dr Ozbolat said: " Hydrogels don't allow cells to grow as normal. The hydrogel confines the cells and doesn't allow them to communicate as they do in native tissues."
Degradation of the hydrogel can also produce toxic compounds that hinder cell growth, he pointed out.
He added: "We can manufacture the strands in any length we want. Because there is no scaffolding, the process of printing the cartilage is scalable, so the patches can be made bigger as well.
"We can mimic real articular cartilage by printing strands vertically and then horizontally to mimic the natural architecture."
The research appears in the latest issue of the journal Scientific Reports.