Researchers in Italy have highlighted an interesting interaction between carbon nanoparticles (C-NPs) and the pluteus larva of Paracentrotus lividus, a sea urchin, which leads to the synthesis of a pearl-like biomaterial through the activation of one of the genes controlling skeletogenesis. Exposing the larva to carbon nanoparticles triggers a defense process that incorporates the nanoparticles into microstructures of aragonite. The biomineralization products were analysed by electron microscopy, X-ray diffraction and Raman spectroscopy.
The nanoparticles did not bring about the rapid death of their host organism. On the contrary, the material induces the organism to perform an elaborate strategy for self-defense and represents a factor that interferes with the correct development of the pluteus larva.
Dose-dependent process
Electron microscopy results show that the pluteus packets the C-NPs in nanoribbons that are then assembled into a more complex structure until aragonite nanorods are generated. This behaviour can be seen in oysters, which envelop external agents in aragonite layers – a process that is activated by the Sp-CyP-1 gene.
In the work, the team shows that the Sp-CyP-1 gene is also present in P. lividus and that expression of the gene is modulated by the presence of NPs.
Using calcein, a polyanionic derivative of fluorescein that binds Ca2+ and other divalent cations, the researchers were able to mark the sites in which there was active biomineralization.
About the author
The work was carried out by two groups with different expertise, working closely together. Dr B Tenuzzo, L Panzarini and E Carata, led by prof. Dini (DiSTeBA – University of Salento), followed the development of larvae in the various phases of embryogenesis, with and without the presence of carbon nanoparticles and supervised the sequencing and the highlighting of gene expression. Prof. A Serra and D Manno (Interdepartmental Laboratory of Physics Applied to Materials Science – University of Salento) took care of the synthesis, structural and morphological characterization of carbon nanoparticles before and after the interaction with the larvae, assisted by Drs A Buccolieri and M Pilippo. Prof. M Rossi (Dipartimento di Scienze di Base ed Applicate per l’Ingegneria – Sapienza Università di Roma) contributed with his valuable experience in carbon nanostructures.
