ZnO and TiO2 Nanocolloids: State of Mechanisms that Regulating the Motility of the Gastrointestinal Tract and the Hepatobiliary System

Olga Tsymbalyuk; Tamara Davydovska; Vladyslav Lisnyak; Stanislav Veselsky; Alexander Zaderko; Ivan Voiteshenko; Anna Naumenko; Valeriy Skryshevsky

doi:10.1021/acsomega.1c02981

ZnO and TiO₂ Nanocolloids: State of Mechanisms that Regulating the Motility of the Gastrointestinal Tract and the Hepatobiliary System

ACS Omega. 2021 Sep 9;6(37):23960-23976. doi: 10.1021/acsomega.1c02981. eCollection 2021 Sep 21.

Authors

Olga Tsymbalyuk¹, Tamara Davydovska¹, Vladyslav Lisnyak^{2

3}, Stanislav Veselsky¹, Alexander Zaderko^{1

4}, Ivan Voiteshenko¹, Anna Naumenko¹, Valeriy Skryshevsky^{1

4}

Affiliations

¹ Institute of High Technologies, Taras Shevchenko National University of Kyiv, 64, Volodymyrska Str, 01033 Kyiv, Ukraine.
² Chemical Faculty, Taras Shevchenko National University of Kyiv, 64, Volodymyrska Str., 01033 Kyiv, Ukraine.
³ Prešov University in Prešov, Ul. 17. Novembra č. 1, 081 16 Prešov, Slovakia.
⁴ Corporation Science Park Taras Shevchenko University of Kyiv, 60, Volodymyrska Str., 01033 Kyiv, Ukraine.

Abstract

Using the transmission electron microscopy (TEM)/high-resolution TEM (HRTEM) and selected area electron diffraction (SAED) methods, it was shown that the nanocolloids of ZnO contain hydrolyzed ZnO nanoparticles (NPs). Typically, the nanocrystalline ZnO/Zn(OH)₂ core is covered by an amorphous shell of zinc hydroxides, preventing the encapsulated crystal core from dissolving. Similar studies were carried out with TiO₂ nanocolloids. It was found that burdening of rats for 30 days with a ZnO aqueous nanocolloid (AN) was accompanied by a narrowing of the amplitude range, a decrease (increase) in the frequency of spontaneous contractions (SCs), and an inhibition of the efficiency indices for smooth muscles (SMs) of the antrum and cecum. Under longer (100 days) burdening of rats with AN of ZnO, there was a tendency toward restoring the above parameters. In terms of the value and the direction of changes in most parameters for SCs of SMs, the effects (30 days) of TiO₂ AN differed from those for ZnO AN and were almost the same in the case of their long-term impact. It was found that mostly M2-cholinoreceptor-dependent mechanisms of regulating the intracellular concentration of Ca²⁺ were sensitive to the effect of ZnO and TiO₂ ANs. The molecular docking demonstrated that ZnO and TiO₂ NPs did not compete with acetylcholine for the site of binding to M3 and M2 cholinoreceptors but may impact the affinity of orthosteric ligands to M2 cholinoreceptors. The studies showed that burdening rats with ZnO and TiO₂ ANs was also accompanied by changes in the activity state of both intracellular enzymes and the ion transport systems for Na⁺, K⁺, and Ca²⁺, related to the processes of bile secretion, via the plasma membrane of hepatocytes.