Ah, eggshells … they could already find use in eco-friendly rubber, carbon capture, ceramics, biodegradable packaging, and energy storage. Now, new research shows that the ubiquitous form of food waste may also be utilized to grow bone for use in transplants.

Ordinarily, if someone is missing bone in one part of their body due to injury or disease, a replacement piece is harvested from one of their leg bones. Not only is this invasive and painful, but it also simply shifts the bone deficit from one part of the skeleton to another.

As an alternative, scientists are now looking at using a patient's own bone cells to grow replacement sections of bone in the lab. Led by Asst. Prof. Gulden Camci-Unal (at right, in the photo below), researchers at the University of Massachusetts - Lowell recently decided to see if they could boost that process … using discarded eggshells. It actually makes sense, as both eggshells and bones are composed largely of calcium.

After being powdered, the shells were added to a gelatin-based hydrogel. That gel in turn served as a three-dimensional scaffolding-like matrix in which bone cells could "roost" and reproduce, eventually forming into solid, natural bone.

When compared to a hydrogel that lacked the powdered eggshells, it was found that the eggy gel boosted the bone cells' ability to grow and harden. This means that replacement bone grown using such a matrix would be ready for implantation faster. And because the bone would be generated using a patient's own cells, it's unlikely that the implanted bone would be rejected by their immune system.

Down the road, the powdered-eggshell gel could possibly also be used to assist in the growing of replacement cartilage, teeth and tendons.

"Global waste of discarded eggshells typically amounts to millions of tons annually from household and commercial cooking," says Camci-Unal. "By repurposing them, we can directly benefit the economy and the environment while providing a sustainable solution to unmet clinical needs."

A paper on the research was published this week in the journal Biomaterials Science.

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