Blue mussel 'glue' for broken bones

Glues produced by marine organisms in wet environments similar to those found in the body are able to withstand the forces created by turbulence. This makes them a great place to look for inspiration when it comes to skeletal bonding.

Growing data suggests that silica or 'bioglass' is superior to hydroxyapatite (the natural mineral found in bone) for bone therapeutics. Scientists are extending previous work producing synthetic glues for soft tissues to the realm of hard tissues in the EU-funded project 'Marine inspired biosilica-filled hydrogels' (DIADOM).

Researchers have developed a modified native chemical ligation (NCL) hydrogel system with a biosilica phase. NCL is a new field for the application of synthetic chemistry to protein synthesis. Two peptide components combine to form a peptide bond at the site of ligation, reliably and simply producing pure samples of proteins difficult to isolate from natural sources.

The DIADOM system uses poly(ethylene glycol) (PEG) precursors to cross-link a polymer network without cytotoxicity. The biosilica comes from sustainably harvested marine organisms grown from agriculture waste feedstocks. The biosilica hydrogel system forms in less than 3 minutes (gelation time) and has been shown to nearly triple its resistance to deformation (Young's modulus) within 24 hours. The rapid gelation and ease of use are quite promising for fixing multiple fragments quickly.

Preliminary in vitro experiments showed no evidence of cytotoxicity. Studies are currently underway to test the cellular response to the biogel system and its intermediates that could be created during degradation. Investigators will evaluate cytotoxicity, inflammatory response and bone cell differentiation in a variety of model systems, including a macrophage cell line and primary human bone marrow stromal cells containing osteogenic precursors.

DIADOM is demonstrating the important benefits of nature-inspired 'glue' to form strong bone-to-bone bonds quickly and easily as a superior alternative to conventional hydroxyapatite. The PEG-based hydrogel with a biosilica phase promises rapid gelation and much easier and more effective repair of splinters and multiple fractures with small pieces. The technology stands to benefit the biomedical field and the patients it serves.