Photodynamic therapy is an advanced method of treating cancer and various benign diseases, including infections. It uses light‐activated molecules [photosensitizers (PSs)] to generate reactive oxygen species (
ROS
) when irradiated with light of a specific wavelength. This study examined the photophysical and photosensitizing activity of the PS chlorin e6 incorporated in a delivery system based on plant phospholipids. This new nanoform of chlorin e6 comprised particles with a diameter of 18.4 ± 2.5 nm and zeta potential of −34.6 ± 3.0 mV. Incorporation of chlorin e6 in phospholipid nanoparticles was observed to cause a bathochromic shift of Q‐band absorption maximum by 14 nm without an absorption change in the range of the Soret band. Fluorescence intensity of chlorin e6 embedded in the phospholipid nanoparticles increased 1.7‐fold. Chlorin e6 in phospholipid nanoparticles, when irradiated, was able to generate
ROS
as shown by oxidation of polyunsaturated fatty acids of the phospholipid matrix of the delivery system and reduced
l
‐glutathione.
In vivo
it was demonstrated that the new nanoform of chlorin e6 provides more accumulation of PSs in tumor tissue than its free form. Moreover, its accumulation in the skin was lower and its elimination from the skin almost five times faster than when administered in free form. The observed differences of this new nanoform of chlorin e6 should lead to enhancement of antitumor efficacy and a decrease in phototoxicity.
In the present study, the electrochemical behavior of antiviral drug umifenovir (Umi) and umifenovir encapsulated in phospholipids micelles (nanosome/umifenovir, NUmi) were investigated for the first time on screen-printed electrodes modified by carbon nanotubes. We have shown that Umi can be electro oxidized around the potential of +0.4 V in the concentration range of 50–500 µM (R2 = 0.992). Non-overlapping signatures of DNA and umifenovir (10–150 µM) permit to register interaction between umifenovir (or umifenovir encapsulated in phospholipids micelles), purine, and pyrimidine heterocyclic bases of DNA separately. The type of interaction is most likely via electrostatic interactions and groove binding in drug-DNA formed complex, as was revealed based on the values of binding constants Kb and the cathodic shifts of oxidation potentials for heterocyclic bases with increasing Umi or NUmi concentration. The negative values of Gibbs free energy (ΔG) for all nucleobases confirm the process spontaneity. This study is the first one presenting the effect of antiviral drug umifenovir and umifenovir encapsulated in phospholipids micelles on dsDNA as a target of pharmacogenomics.
The conditions for the preparation of a drug formulations based on the lipid derivative of sarcolysin embedded in phospholipid nanoparticles have been optimized. The drug is an ultra-thin emulsion with a light transmittance above 80% and a particle size of not more than 50 nm. It should be noted that 99% of the lipid derivative of sarcolysin are incorporated into phospholipid nanoparticles. Preservation of aggregation stability in the aquatic environment was observed for at least 2 days. In vitro experiments have shown that sarcolysin, introduced as a part of phospholipid nanoparticles, is distributed among lipoproteins and protein components of plasma. Moreover, the content of sarcolysin in all fractions involved in the transport of biologically active substances in the body, is significantly higher in case of prodrug administration (lipid derivative of sarcolysin) in the composition of phospholipid nanoparticles than, as compared with administration of a free form (pharmacological substances) to the incubation medium. The transformation of a prodrug into the drug sarcolysin occurs in the blood cells.
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