Two new dinuclear bimetallic complexes, [{PdCl(bipy)}{μ-(pyrazine)}{PtCl(bipy)}]Cl(ClO₄) (1) (bipy is 2,2′-bipyridine) and [{PdCl(en)}{μ-(pyrazine)}{PtCl(en)}]Cl(ClO₄) (2) (en is ethylenediamine), have been synthesized and characterized by elemental microanalysis, IR, ¹H NMR spectroscopy and MALDI-TOF mass spectrometry. The pK_a values of the coordinated water molecules of the diaqua species were determined as well. Substitution reactions of complexes (1) and (2) with thiourea (Tu), L-methionine (L-Met), L-cysteine (L-Cys), L-histidine (L-His) and guanosine-5′-monophosphate (5′-GMP) were studied under the pseudo-first order conditions as a function of nucleophile concentration and temperature. The order of reactivity of nucleophiles was: Tu > L-Met > L-Cys > L-His > 5′-GMP. Substitution reactions with Tu, L-Cys and L-His were followed by decomposition of bimetallic complexes to the corresponding substituted mononuclear complexes [Pd(N–N)(Nu)₂] and [Pt(N–N)(Nu)₂] (N–N = bipy, en), releasing the bridging ligand. However, the structures of starting bimetallic complexes were preserved during the reactions with L-Met and 5′-GMP. The absorption spectroscopic study of interactions of calf-thymus DNA (CT-DNA) with complexes (1), (2) and [{PdCl(bipy)}{μ-(NH₂(CH₂)₆H₂N)} {PtCl(bipy)}]Cl(ClO₄) (3), has shown that all the complexes exhibit high intrinsic binding constants (K_b = 10⁴–10⁵ M⁻¹). DNA–ethidium bromide (DNA–EB) fluorescence was quenched after addition of complexes (1), (2) or (3), indicating displacement of intercalating EB by complexes. All complexes have shown good binding affinity to bovine serum albumin protein (BSA). Chemosensitivity of A375 (human melanoma) and HeLa (human cervical cancer) cell lines toward complexes (1), (2) and (3) was analyzed by SRB assay. Complex (1) displayed significant inhibitory effect on the growth of both cell lines.

The literature data emphasize that nanoparticles might improve the beneficial effects of near-infrared light (NIR) on wound healing. This study investigates the mechanisms of the synergistic wound healing potential of NIR light and silver metal–organic frameworks combined with nitrogen- and sulfur-doped carbon dots (AgMOFsN-CDs and AgMOFsS-CDs, respectively), which was conducted by testing the fibroblasts viability, scratch assays, biochemical analysis, and synchrotron-based Fourier transform infrared (SR-FTIR) cell spectroscopy and imaging. Our findings reveal that the combined treatment of AgMOFsN-CDs and NIR light significantly increases cell viability to nearly 150% and promotes cell proliferation, with reduced interleukin-1 levels, suggesting an anti-inflammatory response. SR-FTIR spectroscopy shows this combined treatment results in unique protein alterations, including increased α-helix structures and reduced cross-β. Additionally, protein synthesis was enhanced upon the combined treatment. The likely mechanism behind the observed changes is the charge-specific interaction of N-CDs from the AgMOFsN-CDs with proteins, enhanced by NIR light due to the nanocomposite’s optical characteristics. Remarkably, the complete wound closure in the in vitro scratch assay was achieved exclusively with the combined NIR and AgMOFsN-CDs treatment, demonstrating the promising application of combined AgMOFsN-CDs with NIR light photodynamic therapy in regenerative nanomedicine and tissue engineering.

Ionizing radiation induces DNA double strand breaks (DSBs) that trigger phosphorylation of the histone protein H2AX (γH2AX). Immunofluorescent staining visualizes formation of γH2AX foci, allowing their quantification. This method, as opposed to Western blot assay and Flow cytometry, provides more accurate analysis, by showing exact position and intensity of fluorescent signal in each single cell. In practice there are problems in quantification of γH2AX. This paper is based on two issues: the determination of which technique should be applied concerning the radiation dose, and how to analyze fluorescent microscopy images obtained by different microscopes. HTB140 melanoma cells were exposed to γ-rays, in the dose range from 1 to 16 Gy. Radiation effects on the DNA level were analyzed at different time intervals after irradiation by Western blot analysis and immunofluorescence microscopy. Immunochemically stained cells were visualized with two types of microscopes: AxioVision (Zeiss, Germany) microscope, comprising an ApoTome software, and AxioImagerA1 microscope (Zeiss, Germany). Obtained results show that the level of γH2AX is time and dose dependent. Immunofluorescence microscopy provided better detection of DSBs for lower irradiation doses, while Western blot analysis was more reliable for higher irradiation doses. AxioVision microscope containing ApoTome software was more suitable for the detection of γH2AX foci.

Apart from cytotoxicity, inhibitors of the COX-2 enzyme have demonstrated additional effects important for cancer treatment (such as radiosensitization of tumor cells and cell antimigratory effects); however, the relationship between the inhibition of other inflammation-related enzyme 5-LOX inhibitors and anticancer activity is still not well understood. In our study, the cytotoxicity of thirteen COX-2 and 5-LOX inhibitors previously presented by our group (1–13) was tested on three cancer cell lines (HCT 116, HT-29 and BxPC-3) and one healthy cell line (MRC-5). Compounds 3, 5, 6 and 7 showed moderate cytotoxicity, but good selectivity towards cancer cell lines. IC₅₀ values were in the range of 22.99–51.66 µM (HCT 116 cell line), 8.63–41.20 µM (BxPC-3 cell line) and 24.78–81.60 µM (HT-29 cell line; compound 7 > 100 µM). In comparison to tested, commercially available COX-2 and 5-LOX inhibitors, both cytotoxicity and selectivity were increased. The addition of compounds 6 and 7 to irradiation treatment showed the most significant decrease in cell proliferation of the HT-29 cell line (p < 0.001). The antimigratory potential of the best dual COX-2 and 5-LOX inhibitors (compounds 1, 2, 3 and 5) was tested by a wound-healing assay using the SW620 cell line. Compounds 1 and 3 were singled out as compounds with the most potent effect (relative wound closure was 3.20% (24 h), 5,08% (48 h) for compound 1 and 3.86% (24 h), 7.68% (48 h) for compound 3). Considering all these results, compound 3 stood out as the compound with the most optimal biological activity, with the best dual COX-2 and 5-LOX inhibitory activity, good selectivity towards tested cancer cell lines, significant cell antimigratory potential and a lack of toxic effects at therapeutic doses.