Bone repairing gene therapy paste

A bone-repairing calcium-rich paste that also carries a fracture-healing gene-therapy DNA message has been developed by scientists in Germany.

The material, which could be injected into broken bones to help fractures to knit back together, consists of a suspension of calcium phosphate nanoparticles mixed with a thickening agent called carboxymethycellulose (CMC) and molecules of DNA.

In tests carried out on cultured cells, inventor Matthias Eppen and his team at Duisberg-Essen University in Germany found that the nanoparticles worked as very effective gene therapy vectors, carrying the DNA into cells, which then expressed the genes it contained.

To find out whether this could include genes capable of promoting repair processes, in an initial series of tests described in a paper published this week in the journal RSC Advances, the researchers used DNA coding for the genes VEGF-A, which stimulates new bone and blood vessel growth, and another bone-growth stimulator, BMP7.

Cells treated in the dish with the new paste showed strong expression of the two factors, suggesting that it could be used to speed up fracture healing and bone repair in the body.

Conversely, the same trick could also be used to deliver molecules called small interfering RNAs (siRNAs) that can turn off certain genes, which could be useful in treating bone cancers by deactivating growth-linked genes that are usually over-active in cancers.