YOUR HEALTH: Printing new knees

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STATE COLLEGE, Pennsylvania – It could be from years of pounding or climbing or just advancing age.   Sometimes the knees aren't what they used to be.

"People can't really even walk and then they have a hard time doing activities in their daily lives," said Dr. Ibrahim Ozbolat, a Penn State University Tissue Engineer.

Inside a Penn State University lab, professor Dr. Ozbolat and his team are engineering a solution.

"We want to make cartilage made of patients' own cells."

Dr. Ozbolat is an expert in three-dimensional bioprinting, the technique of printing layers of living cells to create a 3-D object.    Like this nose, constructed from silicone and printed in the lab.

Now the team is moving down the human body to the knee; producing cartilage patches to repair defects.

"Many of the strategies that we look at for repairing osteochondral defects involve stem cells," said Dr. Daniel Hayes, Penn State Biomedical Engineer.

There are no blood vessels in cartilage tissue, so researchers say it's a good type of tissue for bio-printing.

Using cow cells as a test, Professor Ozbolat's team grows the cartilage into strands that can be used as an ink substitute.

"So the bio-ink is the biological version of the ink that is used in paper printers," Dr. Ozbolat.

In the future, Dr. Ozbolat says stem cells would be removed from a patient, cultured in a lab, the cartilage printed, and then transplanted back into a patient.   That would allow scientists to print new and compatible, human parts.

NEW TECHNOLOGY:  Bioengineers are now beginning to print replacement parts for nose and knee cartilage. Instead of metal or plastic, they are testing strands of lab-grown cartilage using 3D bioprinting; the technique of printing layers of living cells to create a 3D object.   The team is now producing cartilage patches to repair knee defects as well as nose cartilage.   Cartilage is avascular, it is made up of only one cell type and has no blood vessels within the tissue, so the researchers say it`s a good type of tissue for bioprinting.   The team uses cow cells as a test to grow the cartilage into strands that can be used as a 3D substitute.   The future holds the potential for stem cells to be removed from a patient, cultured in a lab for the 3D print, then transplanted back into the patient, someday allowing scientists to print human body parts!   Previous attempts at growing cartilage began with cells embedded in a hydrogel, a substance composed of polymer chains and about 90 percent water that is used as a scaffold to grow the tissue;however, hydrogels don`t allow cells to grow as normal. It confines the cells and doesn`t allow them to communicate as they would in native tissue.  (Source: