Activating the PKA enzyme prior to implantation produces a dramatic improvement in 'in vivo' bone growth. The cells can be observed maturing into bone cells already in the lab; once sown on a carrier and implanted in a mouse, the bone grows well.

The enzyme protein kinase A (PKA) is responsible for many processes in a cell. The messenger ‘cyclic AMP’ activates PKA: adding it to the stem cells ensures that they stimulate one another, the researchers think.

Not only does cyclic AMP promote maturation into bone cells; the cells themselves also secrete various substances that stimulate bone growth. This may explain why mesenchymal stem cells treated with cyclic AMP form significantly more bone than those without the stimulus.

The advantage of administering a bone-growth-stimulating substance in advance is that it can be removed just before implantation.

The recent experiments use a lower hormone concentrations, and the hormones are more closely to resemble the cocktail of hormones normally involved in bone growth.

The research was carried out at the Tissue Regeneration Department of the University of Twente’s Institute for Biomechanical Technology (BMTI). The researchers collaborated with fellow scientists at UMC Utrecht and the Erasmus Medical Center in Rotterdam.