Mitochondria are cell energetic centers where
ATP is produced. They also play a very important role in the
PDT as intracellular sites of
photosensitizer localization.
Photosensitizers gathering in mitochondria (like
porphyrin derivatives used in this work) are more effective in
tumor cell destruction. Moreover, it was assumed that di-
amino acid substituents attached to
porphyrin ring will strengthen the effectivity of interaction with membrane receptors of examined cells. MTT assay was performed to investigate the influence of PP(Arg)(2) and PP(Ala)(2)(Arg)(2)-based
PDT on
breast cancer cell viability for 24 h, 48 h and 120 h after cell irradiation. Then the influence of PP(Ala)(2)(Arg)(2)- and PP(Arg)(2)-mediated
PDT on early mitochondrial apoptosis induction via measurements of the transmembrane mitochondrial potential changes was examined. Results showed that lower energy doses and maximal nontoxic
photosensitizer doses of PP(Ala)(2)(Arg)(2) and PP(Arg)(2) applied in
PDT can imply apoptotic cell death. It was confirmed that modification of the
protoporphyrin IX by attaching two
alanine substituents raised the efficiency of
photodynamic therapy.