Sea urchin coelomocytes cultured on nanoporous aluminium oxide as a potential tool for marine environmental monitoring

Oceans and seas are of paramount importance to the health of planet Earth and human kind. Marine ecosystems should be defended against attack of polluting agents by continuous monitoring; the means of such monitoring should be as green as possible, i.e. based on sensors manufactured by biocompatible and easily disposable raw materials. In this study, we lay the basis for the future development of biosensors of marine environment based on sea urchin cells cultured on nanoporous aluminium oxide. These cells are promising as in previous works they demonstrated high response to stressors, and the proposed substrates have low costs since fabricated by inexpensive anodization process from consumer quality aluminium foils. Coelomocytes of the Mediterranean sea urchin Paracentrotus lividus were cultured on the nanoporous alumina for up to 5 days in vitro. Then, a biochemical characterization was carried out, checking the cholinergic system pathway by means of serotonin autofluorescence induced by aldehyde exposure and by expression and functionality of neuroactive molecules, such as acetylcholinesterase and muscarinic acetylcholine receptors. Both living cell quality and system biochemistry were not affected after the culture, and both electrical modulation and non-self-reactivity were maintained. These findings suggest the possibility of using the sea urchin immune cells cultured on nanoporous alumina as tools for monitoring the marine water quality, based on their electrical response. Graphic abstract