Ispitivanje interakcije fotoosetljivog nanokompozitnog sistema baziranog na nedopiranim i dopiranim česticama titanijum (IV) oksida s biomolekulima i ćelijama
Докторанд
Matijević, MilicaМентор
Đorđević, DraganЧланови комисије
Nakarada, ĐuraNešić, Maja
Korićanac, Lela
Метаподаци
Приказ свих података о дисертацијиСажетак
Nanostructured inorganic compounds such as TiO2 may be used as drug delivery carriers
and photosensitizers (PSs) in light-based therapy – photodynamic therapy (PDT). This
doctoral dissertation explores the implementation of PDT with unmodified TiO2 (colloidal
nanoparticles, TiO2 NPs; prolate nanospheroids, TiO2 PNSs) and modified (doped
nanoparticles, N- and C-TiO2 NPs; conjugated to a cytostatic model in the nanocomposite
systems, NCSs).
Transmission Electron Microscopy confirmed the nanosize (5-104 nm), whereas X-ray
diffraction and Raman spectroscopy revealed predomination of the most photo-active
form – anatase of the investigated TiO2. Afterwards, NCSs were formed by coordination
of TiO2 NPs and PNS to the Ru(II) complex with cytostatic properties – cisdichlorobis(
2,2'-bipyridyl-4,4'-dicarboxylic acid) ruthenium(II). For the modified TiO2,
UV-Vis spectroscopy and bandgap calculations confirmed the visible light absorption.
Electron paramagnetic resonance spectroscopy revealed the... presence of hydroxyl radical
in water suspensions of TiO2 PNSs and C-TiO2 NPs, whereas no reactive oxygen species
were detected in suspensions of TiO2 NPs and N-TiO2 NPs.
For NCS, the long-term constant release profiles of the Ru(II) complex were established
in vitro. Namely, the complex release at pH 7 induced by visible light was slower
compared to UV and light’s absence. Furthermore, additional encapsulation of NCS in the
small unilamellar vesicles significantly suppressed the complex release but with no lightinduced
effect.
Confocal microscopy revealed good cells’ internalization of the assessed TiO2. Viability
tests on non-transformed cells upon the incubation with unmodified TiO2 indicated good
biocompatibility. The photocytotoxic activity of the investigated TiO2 was tested on
several cancer cell lines. The most significant viability reduction has been achieved by the
combined treatment with C-TiO2 NPs and blue light on the HeLa cell line. Moreover, CTiO2
NPs promoted the programmed cells’ death mechanisms, contributing to their
exceptional PS features for PDT.