Hemocompatibility of biogenic phosphorus nano-agromaterials at environmentally relevant and supra-environmental concentrations for occupational exposure

Abstract

Phosphorus (P)-based nanomaterials (NMs), such as those derived from rock phosphate (RP) and hydroxyapatite (HAP), have the potential to be used as nanofertilisers to supplement depleting P levels in agricultural soils. Before applying to agricultural areas, complete profiling is essential to assess the potential risk to human health from occupational exposure, particularly for the predicted environmentally relevant concentration (ERC) magnitudes. A systematic investigation on blood contact properties such as percent hemolysis, platelet aggregation, blood coagulation time, and interactions with serum plasma protein was performed in this ex vivo study using National Institute of Health (NIH) guidelines. For ERCs (0-50 μg mL−1) and supra-environmental concentrations (SECs, 50-1000 μg mL−1), the effects of biologically synthesised nanohydroxyapatite (nHAP) and nanophosphorus (nP) were compared to those of chemically synthesised and commercially available nHAPs and bulk RP. Our results show that biogenic nHAP and nP did not have any significant effect on hemolysis, platelet aggregation or coagulation processes at ERCs and SECs whereas the bulk RP had significant hemotoxic effects. Protein quantification analysis revealed that proteins from blood serum adsorb onto NMs, forming a biomolecular corona. Our results highlight the hemocompatible behaviour of biologically synthesized P-based NMs at predicted ERCs, which are most likely to be occupational exposures. These findings may provide a fundamental understanding of the overall risks presented by P-based nanofertilisers.