London, Feb 14 (IANS) Spanish scientists are researching nacre, which could potentially open the way to biomedical applications and also for regenerating human bones.

Nacre, known as mother of pearl, is an organic-inorganic composite material produced by some molluscs as an inner shell layer. It is strong, resilient, and iridescent. This substance is called “mother of pearl” because it is literally the “mother” or creator, of true pearls.

The study authors from the Universities of Granada, Aveiro (Portugal) and Spanish National Research Council (CSIC), analysed gastropods’ nacre in detail. Such nacre grows forming block towers, as piles of coins, unlike bivalves (nuculas, mussels, nacras, pearl oysters), which grow just like terraces of tablets.

Nacre is made up of blocks of aragonite separated by membranes of polysaccharides and proteins, just like bricks and mortar in a wall. The nacre grows in terraces because it is limited by a superficial membrane which covers and protects it from sea water when the animal goes into its shell, said a Granada release.

Such superficial membrane must carry out different tasks in order to permit the production of nacre and therefore it is “a wonderfully complex structure”, according to the study authors.

This work has been recently published in the journal PNAS.