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.

In the last decade, targeting membrane lipids in cancer cells has been a promising approach that deserves attention in the field of anticancer drug development. To get a comprehensive understanding of the effect of the drug [Ru(η⁵-Cp)(PPh₃)₂CN] (RuCN) on cell lipidic components, we combine complementary analytical approaches, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectroscopy. Techniques are used for screening the effect of potential metallodrug, RuCN, without and with drug carriers (carbon dots (CDs) and nitrogen-doped carbon dots (N-CDs)) on the lipids of the human ovarian cancer cell line A2780. MALDI TOF MS results revealed that the lysis of ovarian cancer membrane lipids is promoted by RuCN and not by drug carriers (CDs and N-CDs). Furthermore, SR-FTIR results strongly suggested that the phospholipids of cancer cells undergo oxidative stress after the treatment with RuCN that was accompanied by the disordering of the fatty acid chains. On the other hand, using (N-)CDs as RuCN nanocarriers prevented the oxidative stress caused by RuCN but did not prevent the disordering of the fatty acid chain packing. Finally, we demonstrated that RuCN and RuCN/(N-)CDs alter the hydration of the membrane surface in the membrane–water interface region.

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.

The possibilities for the application of various TiO ₂ nanocrystals for substrate-assisted laser desorption/ionization time-of-flight mass spectrometric quantitative analysis of steroid hormones, amino acids and saccharides is presented in this work.