Jaroslaw Piskorz

Current status of liposomal porphyrinoid photosensitizers.

The complete eradication of various targets, such as infectious agents or cancer cells, while leaving healthy host cells untouched, is still a great challenge faced in the field of medicine. Photodynamic therapy (PDT) seems to be a promising approach for anticancer treatment, as well as to combat various dermatologic and ophthalmic diseases and microbial infections. The application of liposomes as delivery systems for porphyrinoids has helped overcome many drawbacks of conventional photosensitizers and facilitated the development of novel effective photosensitizers that can be encapsulated in liposomes. The development, preclinical studies and future directions for liposomal delivery of conventional and novel photosensitizers are reviewed.

Diazepinoporphyrazines Containing Peripheral Styryl Substituents and Their Promising Nanomolar Photodynamic Activity against Oral Cancer Cells in Liposomal Formulations

The photochemical properties and photodynamic activity of three porphyrazines (Pzs) containing annulated diazepine rings, including novel demetalated porphyrazine‐possessing bis(styryl)diazepine moieties were investigated. The porphyrazines were evaluated in terms of their electronic absorption and emission properties, their tendency to undergo aggregation and photodegradation, as well as their singlet oxygen generation efficiency. The in vitro photodynamic activity of the porphyrazines and their liposomal formulations were examined by using two oral squamous cell carcinoma cell lines. Magnesium(II) tribenzodiazepinoporphyrazine (1) revealed the highest phototoxic effect in both cell lines used, H413 and HSC‐3. Encapsulation of Pz 1 into L‐α‐phosphatidyl‐d,l‐glycerol:1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine liposomes resulted in a nearly threefold increase in photocytotoxicity relative to that of the solution of Pz 1 (IC50 values of 45 and 129 nM, respectively).

Liposomal formulations of magnesium sulfanyl tribenzoporphyrazines for the photodynamic therapy of cancer

Photodynamic therapy of cancer comprises the activation of photosensitizer molecules delivered to cancer cells, to generate reactive oxygen species that mediate cytotoxicity. In this study, previously synthesized dendritic magnesium tribenzoporphyrazines were incorporated into four types of liposomes containing either 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as the zwitterionic lipids. The addition of either l-α-phosphatidyl-dl-glycerol (PG) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) imparted a negative or positive charge, respectively. Novel formulations were tested in oral squamous cell carcinoma cell lines (CAL 27, HSC-3) as well as cervical adenocarcinoma cells (HeLa). Positively charged DOTAP:POPC liposomes were the most effective carriers for all tested tribenzoporphyrazines. Calculated IC50 values for DOTAP:POPC liposomes indicated that the incorporation of tribenzoporphyrazines into these liposomes can improve photocytotoxicity up to 50-fold compared to the free forms of macrocycles. Oral cancer cells (CAL 27 and HSC-3) were more sensitive to liposomal photodynamic treatment than HeLa cells.

Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode — effect of nitro peripheral groups on electrochemical properties

We report on the synthesis, MS, UV-vis, NMR, HPLC and electrochemical characterization of magnesium sulfanyl porphyrazine with 2-[2-(4-nitrophenoxy)ethoxy]ethylsulfanyl substituents in the periphery. The electrochemical properties of novel macrocycle were studied by cyclic voltammetry and differential pulse voltammetry in non-aqueous electrolyte. The experimental data indicated the occurrence of clearly defined four redox couples corresponded to one-electron reactions of the π-conjugated porphyrazine ring and substituents in the periphery. Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on a glassy carbon electrode allowed for the evaluation of the effect of nitro peripheral groups on the electrochemical properties. The electrochemical behavior of immobilized nitro porphyrazine was consistent with the reduction mechanism for the various arylnitro compounds in aqueous media, with two processes characteristic of the redox transitions of the arylnitro group to the corresponding arylhydrox...