Published: Jan. 11, 2017

"We can rebuild him. We have the technology," began every episode of the television show The Six Million Dollar Man. Unfortunately, in the real world, medicine has not been able to create flawless substitutes for human body parts. The devices we have, like replacement knees and hips, are imperfect and often wear out and must be swapped out again.

Department of Mechanical Engineering Associate Professor Corey Neu would like to change that, using material from our own bodies as healing technologies.

Filling A Need

"There is this unmet need to regenerate damaged or diseased parts of the body. Right now there are few good solutions," says Neu.

Neu and his team of researchers are focusing on joint damage, a problem that affects tens of millions of people. It's most commonly the result of sports injuries or osteoarthritis, which occurs when the cartilage that cushions our joints wears down and is most commonly seen in older people.

"There are no current clinical options for regenerating articular cartilage. We've come up with a strategy that's very promising," says Neu.

Degraded cartilage is such a problem in medicine because this tissue has only limited ability to heal itself. Scientists have tried regenerating cartilage in labs, but have had little luck.

Neu is taking a different approach. Instead of trying in vain to regrow cartilage, his team is instead recycling body tissues and molecules to combine and adapt them into clever cartilage substitutes.

Promising Results

They recently published two research papers in the journal Advanced Functional Materials on work that is showing positive initial results.

 In the first, they compressed collagen fibers and collapsed them around stem cells. After increasing the collagen density, it started to act more like cartilage and take on the natural shape and organization similar to the native tissue.

The second paper covers experiments taking healthy cartilage that had been crushed down into micro particles. They then stripped out the cells, leaving the old tissue structure behind. When they combined the remaining micro particles into densified collagen with stem cells, the new tissue again started to behave more like cartilage with favorable mechanical properties and cellular responses similar to the native tissue.

Neu’s work is much more than ‘slides under a microscope’, and may be useful for tissue replacements in damaged knees.

Particle Clay

"It forms a particle clay, and you can pick it up in your hands and squeeze a stiff tissue substitute that feels like regular cartilage. It's really amazing," says Neu.

As a project that hopes to eventually be used in humans, Neu has organized a team of researchers that go beyond CU Boulder. He is working with doctors at the CU Anschutz Medical Campus, as well as veterinary medicine faculty at Colorado State University.

While the work is still fairly early, there's clear promise. The team recently submitted patent applications, and is planning preclinical studies prior to testing in people.

Paper #1: Microstructures: Mechanisms and Microenvironment Investigation of Cellularized High Density Gradient Collagen Matrices via Densification
Paper #2: Decellularized Cartilage Microparticles: Dissociated and Reconstituted Cartilage Microparticles in Densified Collagen Induce Local hMSC Differentiation