Novel non-peripheral mercaptopyridine-substituted mono- and double-decker lutetium(III) phthalocyanines: synthesis, photophysicochemical and electrochemical properties.

In this study, novel non-peripheral tetra-mercaptopyridine-substituted mono- and double-decker phthalocyanines (LuPc and LuPc2) containing lutetium(III) as a rare earth metal were synthesized and characterized using different spectroscopic techniques. ESR and electrochemical analyses were performed to support the sandwich structure of LuPc2. The g factor was determined to be 2.00039 and the characteristic first reduction couple at 0.29 V indicated a reduction of the radical Pc ring of LuPc2. In addition, the UV-Vis-NIR spectra of LuPc2 in neutral, reduced, and oxidized states demonstrate its intrinsic π-radical nature in CHCl3. The photophysicochemical properties of LuPc and LuPc2 were investigated in DMSO. It was found that mono-phthalocyanine (LuPc) is a more effective photosensitizer than double-decker (LuPc2) and metal-free (H2Pc) phthalocyanines based on a comparison of their photophysical and photochemical properties. The singlet oxygen quantum yields (ΦΔ) of the synthesized LuPc and LuPc2 compounds were calculated to be 0.57 and 0.14, respectively, and the obtained results were compared with H2Pc (ΦΔ = 0.04). Also, electrochemical measurements were performed to estimate their redox potentials and the results indicated the important electrochemical performance of double-decker phthalocyanine (LuPc2).

A Novel PEtOx-Based Nanogel Targeting Prostate Cancer Cells for Drug Delivery.

This study focuses on creating a specialized nanogel for targeted drug delivery in cancer treatment, specifically targeting prostate cancer. This nanogel (referred to as SGK 636/Peptide 563/PEtOx nanogel) is created using hydrophilic poly(2-ethyl-2-oxazoline) (PEtOx) through a combination of living/cationic ring-opening polymerization (CROP) and alkyne-azide cycloaddition (CuAAC) "click" chemical reactions. A fluorescent probe (BODIPY) is also conjugated with the nanogel to monitor drug delivery. The characterizations through 1 H-NMR, and FT-IR, SEM, TEM, and DLS confirm the successful production of uniform, and spherical nanogels with controllable sizes (100 to 296 nm) and stability in physiological conditions. The biocompatibility of nanogels is evaluated using MTT cytotoxicity assays, revealing dose-dependent cytotoxicity. Drug-loaded nanogels exhibited significantly higher cytotoxicity against cancer cells in vitro compared to drug-free nanogels. Targeting efficiency is examined using both peptide-conjugated and peptide-free nanogels, with the intracellular uptake of peptide 563-conjugated nanogels by tumor cells being 60-fold higher than that of nanogels without the peptide. The findings suggest that the prepared nanogel holds great potential for various drug delivery applications due to its ease of synthesis, tunable functionality, non-toxicity, and enhanced intracellular uptake in the tumor region.

Water-soluble phthalocyanine photosensitizers for photodynamic therapy.

Photodynamic therapy (PDT) is based on a photochemical reaction that is started when a photosensitizing process is activated by the light and results in the death of tumor cells. Solubility is crucial in PDT applications to investigate the physical and chemical characteristics of phthalocyanines, but, unfortunately, most phthalocyanines show limited solubility especially in water. To increase the solubility of phthalocyanines in polar solvents and water, ionic groups such as -SO3-, -NR3+, -COO-, and nonionic groups such as polyoxy chains are frequently added to the peripheral or nonperipheral positions of the phthalocyanine framework. Since water-solubility and NIR-absorbing properties are essential for efficient PDT activation, studies have been focused on the synthesis of these types of phthalocyanine derivatives. This review focuses on the photophysical, photochemical, and some in vitro or in vivo studies of the recently published ionic and nonionic phthalocyanine-mediated photosensitizers carried out in the last five years. This review will have positive contributions to future studies on phthalocyanine chemistry and their PDT applications as well as photochemistry.

A highly sensitive "ON-OFF-ON" dual optical sensor for the detection of Cu(II) ion and triazole pesticides based on novel BODIPY-substituted cavitand.

The synthesis with full structural characterization including elemental analysis and 1H, 13C, 11B and 19F NMR, FT-IR and MALDI-TOF spectral data, along with the florescence sensing behavior of a new resorcin[4]arene cavitand 3 bearing multiple BODIPY sites achieved by the Cu-catalyzed azide-alkyne cycloaddition (CuAAC) is being reported. The spatial orientation of multiple BODIPY-1,2,3-triazole arms based on the macrocyclic rigid core is of great interest since the resulting structure has been utilized as a fluorescent chemosensor for numerous metal cations. In particular, a remarkable decrease in the fluorescence emission towards Cu(ii) ions, i.e., "turn-off" response, has been obtained giving rise to an optical sensor for the detection of triazole fungicides, namely tebuconazole, triadimenol, triadimefon, i.e. "turn-on" response. Such a molecular system, hence, can be feasibly applied as a dual optical sensor, i.e. "a turn-on-off-on" system, for dangerous contaminants such as heavy metals and pesticides.

Synthesis of peripheral and non-peripheral substituted metallophthalocyanines containing (E)-3-(5-bromo-2-hydroxphenyl)-1-o-tolyprop-2-en-1-one: Investigation of the photophysical and photochemical properties.

In this study, the novel peripherally (5-7) and non-peripherally (9-11) metallo (zinc, magnesium and lead) phthalocyanine derivatives were synthesized from their (E)-4-(4-bromo-2-(3-oxo-3-o-tolyprop-1-enyl)phenoxy) substituted phthalonitrile precursors (4 and 8). These novel phthalocyanine derivatives including chalcone groups were characterized by spectroscopic techniques such as FT-IR, UV-vis, 1H NMR, 13C NMR and MALDI-TOF mass spectra. In the next stage, the photophysical and photochemical properties of synthesized compounds were searched in DMSO which is not cause toxic effects at a certain concentration in biological applications. As a result of investigations, it was determined that phthalocyanine complexes did not demonstrate aggregation in DMSO solutions.

A novel selective fluorescent chemosensor for Fe 3+ ions based on phthalonitrile dimer: synthesis, analysis, and theoretical studies.

Phenyl-4,4-di(3,6-dibutoxyphthalonitrile) ( 3 ) was synthesized by the reaction of 1,4-phenylenebisboronic acid ( 1 ) and 4-bromo-3,6-dibutoxyphthalonitrile ( 2 ), using Suzuki cross-coupling reaction. The newly synthesized compound ( 3 ) was characterized by FT-IR, MALDI-MS, ESI-MS, 1 H-NMR, 13 C-NMR, and 13 C-DEPT-135-NMR. The fluorescence property of phenyl-4,4-di(3,6-dibutoxyphthalonitrile) ( 3 ) towards various metal ions was investigated by fluorescence spectroscopy, and it was observed thatthe compound ( 3 ) displayed a significantly 'turn-off' response to Fe 3+ , which was referred to 1:2 complex formation between ligand ( 3 ) and Fe 3+ . The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe 3+ ions.

Axially substituted silicon(IV) phthalocyanine and its quaternized derivative as photosensitizers towards tumor cells and bacterial pathogens.

Axially di-(alpha,alpha-diphenyl-4-pyridylmethoxy) silicon(IV) phthalocyanine (3) and its quaternized derivative (3Q) were synthesized and tested as photosensitizers against tumor and bacterial cells. These new phthalocyanines were characterized by elemental analysis, and different spectroscopic methods such as FT-IR, UV-Vis, MALDI-TOF and 1H NMR. The photophysical properties such as absorption and fluorescence, and the photochemical properties such as singlet oxygen generation of both phthalocyanines were investigated in solutions. The obtained values were compared to the values obtained with unsubstituted silicon(IV) phthalocyanine dichloride (SiPcCl2). The addition of two di-(alpha,alpha-diphenyl-4-pyridylmethanol) groups as axial ligands showed an improvement of the photophysical and photochemical properties and an increasement of the singlet oxygen quantum yield (ΦΔ) from 0.15 to 0.33 was determined. The photodynamic efficacy of synthesized photosensitizers (3 and 3Q) were evaluated with promising photocytotoxicity (17% cell survival for 3 and 28% for 3Q) against the cervical cancer cell line (HeLa). The photodynamic inactivation of pathogenic bacterial strains Streptococcus mutans, Staphylococcus aureus, and Pseudomonas aeruginosa suggested a high susceptibility with quaternized derivative (3Q). The both Gram-positive bacterial strains were fully photoinactivated with 11µM 3Q and mild light dose 50J.cm-2. In case of P. aeruginosa the effect was negligible for concentrations up to 22µM 3Q and light dose 100J.cm-2. The results suggested that the novel axially substituted silicon(IV) phthalocyanines have promising characteristic as photosensitizer towards tumor cells. The quaternized derivative 3Q has high potential for photoinactivation of pathogenic bacterial species.