A team of researchers from the University of Michigan has developed a new technique to aid bone repair, using polymer nano-shells to deliver microRNA molecules. The method could one day have a big impact on regenerative medicine, directing cells already present at injury sites to aid healing.

The new study builds on previous research conducted back in 2011, where nanofiber microspheres were used to carry cells to injury sites to help the wound-healing process. The new work uses the same idea, but rather than transporting foreign cells, focuses on making better use of the cells already at the wound site.

The team developed tiny polymer spheres that are able to easily breach cell walls, carrying microRNA molecules to cells at bone wound sites. The spheres are designed to protect the molecules during transit, degrading once in place in cells at the site of the wound.

At that point, the microRNA molecules are able to instruct their host cells, switching on healing and bone building mechanisms, significantly aiding the healing process. The protective polymer spheres are also engineered to degrade slowly, allowing for long-term release of microRNA molecules, meaning that the therapy can continue for a month or more.

This method has a number of benefits over existing treatments that seek to introduce foreign healing cells to the wound. Such cells can be rejected by the host, and don't always behave as desired, leading to tumors.

The new method was tested on osteoporotic laboratory mice, where it successfully aided bone wound healing. In future, the tech could be useful in numerous use cases, such as helping to ease the joint repair processes or tackling tooth decay.

"The new technology we have been working on opens doors for new therapies using DNA and RNA in regenerative medicine and boosts the possibility of dealing with other challening human diseases," said study lead Peter Ma.

The researchers intend to continue their work, studying the technology in use on larger animals, evaluating it for potential future use in humans.

The team published its research in the journal Nature Communications.

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