Manipulated sperm motility via soot nanoparticles-induced biochemical alterations in human seminal plasma

Obtaining spermatozoa with progressive motility, via postejaculatory activation with pharmacological agents such as theophylline and pentoxifylline, is crucial for the success rate of assisted reproduction in couples with severe male factor infertility. Regrettably, the possibility of premature acrosome reactions and impared oocyte function questions the practical applicability of phosphodiesterase inhibitors. The rapid development of nanotechnologies promotes the use of hydrophobic rapeseed oil soot as a non-cytotoxic biomaterial for sperm motility activation, but the scarcity of knowledge regarding the interactions of soot with components from the seminal plasma hinders the eventual commercialization of this cutting-edge approach. Aiming to eliminate this short-coming, the current study shows for the first time how the soot nanomaterials alter the biochemistry of human seminal plasma. Upon 270 min incubation with soot nanoparticles, the activity of AST, ALT, CK, LDH and GGT enzymes in the seminal plasma of ten patients changes inversely to the registered sperm motility (i.e., lower enzyme activity, higher sperm motility and vice versa). This phenomenon is primarily related to termination of the enzymes-substrate binding or extraction of enzymes from the gametes via chemical bonding with the soot. These novel mechanisms depend on the physicochemical features of used carbon nanomaterials, revealing opportunities for predictable tuning of the sperm reproductive potential.