When nanomaterials (NM) come in contact with the biological medium, the particle
surface adsorbs molecules from the environment. These molecules form a corona that
determines the characteristics and impact of NM on biological systems. The purpose
of this master's thesis is to study the impact of selected NM with a protein corona on
the activity of the acetylcholinesterase (AChE) enzyme in cells in vitro. Ellman's
method was used to test the enzyme activity. SH-SY5Y cells were exposed to TiO2,
SiO2, ZnO, and TiOx nanoparticles (NP) for 24 hours. Yellow product formed by the
reaction of AChE with acetylthiocholine chloride was measured with a
spectrophotometer at 405 nm. The impact of TiO2, ZnO, and TiOx NP with formed
corona is dose-dependent, while in NP SiO2 with formed corona the impact on the
enzyme is similar at all concentrations. The impact of TiO2 (E171-E, G10-4, 67-CC)
and ZnO NP without formed corona is also dose-dependent. The other NP without
formed corona had a similar impact on the enzyme at all concentrations. The impact
of NP on the activity of the AChE enzyme depends on the type of corona. NP with
formed corona were coated with bovine serum albumin. The NP without prior corona
were surrounded by molecules upon contact with the DMEM medium. Most NP with
bovine serum albumin corona increased AChE activity, whereas NP without prior
corona decreased the enzyme activity. For NP without prior corona, we suggest that
uptake by endocytosis was reduced due to aggregate formation, but this hypothesis
was not verified.
|
