Ultrasound versus Light: Exploring Photophysicochemical
and Sonochemical Properties of Phthalocyanine-Based Therapeutics,
Theoretical Study, and In Vitro Evaluations
posted on 2022-03-03, 19:03authored byEmre Güzel, Göknur Yaşa Atmaca, Aleksey E. Kuznetsov, Aysegul Turkkol, Mehmet Dincer Bilgin, Ali Erdoğmuş
Photodynamic
therapy (PDT) applications carried out with the assistance
of ultrasound have attracted significant attention in recent years.
The use of phthalocyanines, which are an important component as photosensitizers
in PDT, is becoming more important day by day. In therapeutic applications,
phthalocyanines can promote the production of reactive oxygen species.
Motivated by this fact, the syntheses of metal-free (2), gallium (3), and indium (4) phthalocyanines
have been achieved by substituting 4-(cinnamyloxy)phthalonitrile for
the first time to evaluate their therapeutic applications. Additionally,
photophysicochemical, sonophotochemical, and in vitro evaluations
of phthalocyanines have been reported. To the best of our knowledge,
this is the first study of the use of phthalocyanines with different
metal ions as potential photosensitizers for sonophotodynamic therapy
(SPDT) applications in gastric cancer cell lines. The results show
that the quantum yield of the generation of singlet oxygen increased
in sonophotochemical studies (ΦΔ = 0.55 (2), 0.85 (3), 0.96 (4)), compared
to photochemical studies (ΦΔ = 0.22 (2), 0.61 (3), 0.78 (4)). The density
functional theory (DFT) results are in good agreement with the experimental
results and suggest increased reactivity of phthalocyanines 3 and 4 in various redox processes, thus implying
their applicability and usefulness as potential therapeutic agents.
These phthalocyanines are effective sensitizers for PDT, sonodynamic
therapy (SDT), and SPDT against MKN-28 gastric cancer cell line in
vitro. All three treatments decreased cell viability and induced apoptosis
in the gastric cancer cell line. However, indium phthalocyanine (4)-mediated SPDT was a more effective treatment modality compared
to indium phthalocyanine (4)-mediated PDT and SDT. Also,
indium phthalocyanine (4) was found to be a more effective
sensitizer to activate apoptosis compared to the other phthalocyanines.
To sum up, phthalocyanine-mediated SPDT enhances the cytotoxic effect
on gastric cancer cells more than the effect of SDT or PDT alone.