| Abstract | Melanom je zloćudni tumor kože koji nastaje prilikom maligne
transformacije melanocita, a zbog agresivnosti te metastatske prirode
predstavlja najsmrtonosniji oblik raka kože. Konvencionalne strategije u
liječenju raka poput radioterapije, kemoterapije i biološke terapije često
uzrokuju nuspojave te ne mogu nadvladati problem rezistencije tumora i
hipoksičnog tumorskog mikrookoliša. Jedno od inovativnih rješenja
predstavlja oblik minimalno invazivne i kliničke odobrene fototerapije,
fotodinamička terapija. Fotodinamička terapija temelji se na interakciji
svjetlosti, fotosenzibilizatora i kisika pri čemu dolazi do fotokemijske
reakcije i generiranja reaktivnih kisikovih vrsta koje zatim uzrokuju smrt
tumorskih stanica, oštećenje tumorskog krvožilja i potiču imunološki
odgovor.
Svrha ovog rada bila je ispitati djelotvornost piridilporfirina konjugiranih
lipofilnim lancima različitih duljina pri čemu su dva spoja N-oksidirana, a
dva N-metilirana. Mjerenjem intenziteta fluorescencije ispitana je količina
spojeva koji ulaze u stanice u različitim vremenskim intervalima,
fluorescentnom mikroskopijom praćena je lokalizacija porfirina u stanicama
te je pomoću MTT testa određena citotoksičnost porfirina u uvjetima
normoksije i hipoksije. Rezultati ispitivanja pokazali su kako se spojevi u
najvećoj količini nalaze u stanicama nakon 6 h inkubacije te da u većoj
količini ulaze u stanice fibroblasta (HDF). Također, pokazano je kako
porfirini u većoj količini ulaze u stanice pri 37 ℃ što bi moglo ukazati na
ulazak porfirina aktivnim transportom u stanice. Rezultati MTT testa
ukazuju na potencijalnu selektivnost porfirina za stanice melanoma (MEWO)
u koncentracijama 0.5 i 1 μΜ te pokazuju kako porfirini nisu citotoksični u
mraku. Potvrđeni su i rezultati prethodnih ispitivanja gdje je pokazano kako
veća lipofilnost spojeva utječe na bolji ulazak u stanicu te da N-oksidirani
spojevi potencijalno bolje djeluju u uvjetima hipoksije. |
| Abstract (english) | Melanoma is a malignant skin tumor that arises during the malignant
transformation of melanocytes, and due to its aggressiveness and
metastatic nature, it is the deadliest form of skin cancer. Conventional
strategies in cancer treatment such as radiotherapy, chemotherapy, and
biological therapy often cause side effects and are not able to overcome the
problem of tumor resistance and hypoxia in the tumor microenvironment.
One of the solutions is photodynamic therapy (PDT), a form of minimally
invasive and clinically approved phototherapy. PDT is based on the
interaction of light, photosensitizer, and oxygen, whereby a photochemical
reaction occurs and the generation of reactive oxygen species is generated,
which then causes the death of tumor cells, damages tumor blood vessels,
and stimulates the immune response.
The aim of this work was to test the effectiveness of porphyrins conjugated
with lipophilic chains of different lengths, where two have N-oxidized and
two N-methylated pyridyl groups on meso position. The cell uptake of
porphyrins at different time points was determined by measuring the
fluorescence intensity, fluorescence microscopy was used to examine the
localization of porphyrins inside melanoma cell line, and the cytotoxicity of
porphyrins was determined under normoxia and hypoxia using the MTT
proliferation test. The results showed that the largest amount of the
porphyrins was found in the cells after 6 h of incubation, and in larger
amount in fibroblasts (HDF) in comparison to melanoma cell line (MeWO).
Also, it was shown that porphyrins enter the cells in larger quantities at
37 ℃, which could indicate the entry of porphyrins by active transport into
the cells. The results of the MTT test showed the potential selectivity of
porphyrins for melanoma cells (MEWO) and show that porphyrins do not
show dark toxicity in concentration up to 10 μM. The results of previous
tests were also confirmed, showing that the higher lipophilicity of the
compounds results in better cellular uptake and that N-oxidized compounds
potentially work better in hypoxia |
