engleski

Synthesis, photophysical, photochemical and photobiological properties of amphiphilic Zn(II) and free base tripyridylporphyrins

Photodynamic therapy (PDT) is a cancer treatment that has been increasingly investigated. Photosensitizer (PS), light and oxygen are main components of PDT, and in their combination reactive oxygen species (ROS) are produced, which can lead to cytotoxic effect within the cell and consequent destruction of cancerous tissue [1]. The desired characteristics of the PS include stability of the molecule, high production of singlet oxygen and other ROS, good absorption in red or infrared region, negligible toxicity without irradiation and relative fast excretion from the body [2]. Porphyrins are often used as PSs because their structure can be relatively easily modified to achieve adequate lipophilicity of the molecule, or chelated by different cations, such as Zn(II) in our work. Amphiphilic molecules can facilitate cellular uptake while maintaining good water solubility [3], and Zn(II) is expected to increase the lifetime of the excited triplet state (3PS*), and thus the production of singlet oxygen [4]. In addition to the PS, light also plays an important role in PDT, so the optimal dose of light and the appropriate irradiation wavelenght should be selected [5]. Here we will present two groups of tripyridylporphyrins, Zn(II) and free-based, both conjugated with chains of different length. Spectroscopic properties of the ground state, as well as the excited state, of the obtained compounds were studied by using laser flash photolysis (LFP) and time-resolved single photon counting (TC-SPC). Lipophilicity and singlet oxygen production, which was investigated by using modified relative methods, will also be presented. In vitro studies of the PSs’ biological properties included evaluation of cytotoxicity on melanoma cell line (MeWo) and human foreskin fibroblasts (HFF), with two light sources used for photoactivation, with irradiation wavelength at 605 nm (orange light) and 645 nm (red light).

Photodynamic therapy ; Amphiphilic porphyrins ; Zn(II) chelation ; Lipophilicity ; Singlet oxygen production ; Fluorescence ; Melanoma cells

nije evidentirano