The cause–effect relationships between physicochemical properties of amphiphilic [60]fullerene derivatives and their toxicity against bacterial cells have not yet been clarified. In this study, we report how the differences in the chemical structure of organic addends in 10 originally synthesized penta-substituted [60]fullerene derivatives modulate their zeta potential and aggregate’s size in salt-free and salt-added aqueous suspensions as well as how these physicochemical characteristics affect the bioenergetics of freshwater Escherichia coli and marine Photobacterium phosphoreum bacteria. Dynamic light scattering, laser Doppler micro-electrophoresis, agarose gel electrophoresis, atomic force microscopy, and bioluminescence inhibition assay were used to characterize the fullerene aggregation behavior in aqueous solution and their interaction with the bacterial cell surface, following zeta potential changes and toxic effects. Dynamic light scattering results indicated the formation of self-assembled [60]fullerene aggregates in aqueous suspensions. The measurement of the zeta potential of the particles revealed that they have different surface charges. The relationship between these physicochemical characteristics was presented as an exponential regression that correctly described the dependence of the aggregate’s size of penta-substituted [60]fullerene derivatives in salt-free aqueous suspension from zeta potential value. The prevalence of DLVO-related effects was shown in salt-added aqueous suspension that decreased zeta potential values and affected the aggregation of [60]fullerene derivatives expressed differently for individual compounds. A bioluminescence inhibition assay demonstrated that the toxic effect of [60]fullerene derivatives against E. coli cells was strictly determined by their positive zeta potential charge value being weakened against P. phosphoreum cells in an aquatic system of high salinity. Atomic force microscopy data suggested that the activity of positively charged [60]fullerene derivatives against bacterial cells required their direct interaction. The following zeta potential inversion on the bacterial cells surface was observed as an early stage of toxicity mechanism that violates the membrane-associated energetic functions. The novel data about interrelations between physicochemical parameters and toxic properties of amphiphilic [60]fullerene derivatives make possible predicting their behavior in aquatic environment and their activity against bacterial cells.

Birds have evolved in direct contact with natural nanoparticles (NPs) that are identical to artificial trace-element NPs. This relationship, the high action potential and their ability to reduce environmental pollution make NPs a promising component of bird diets. However, from available published studies there is no unity in justifying the applied dosages of NPs and their calculations. NPs are used in the studies in various doses, for example: Cu 0.5-50 mg/kg, Ag 10-1000 mg/kg, Se 0.2-5 mg/kg, Cr 500-1500 ppb. Therefore, universal approaches and criteria of NP investigations are necessary for the establishment of their use in feed. The mechanisms of action of the trace elements in artificial NPs in birds vary from the those of ionic forms of trace elements, which determine the differences in the productive effect. According to data from different authors, chickens receiving NPs in feed have higher chickens body weight by 13-24%. Such benefits have increased interest in sources of trace-element NPs significantly over the past two decades. The design of trace-element NPs has led to promising developments in the safe use of NPs for poultry nutrition, such as coating NPs with inert substances and adjusting their size. However, constraining circumstances determined by the difficulty of predicting the toxic properties of nanostructures exist, even though artificial trace-element NPs are a relatively safe class of nanostructures due to their production requirements, and metal NPs are already used in human food and medicine. The following review discusses the benefits and potential hazardous effects of NPs and the possibility of using them as feed supplements for poultry.