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We report herein the design, synthesis, and biological investigation of a series of novel Pt(IV) prodrugs with non-steroidal anti-inflammatory drugs naproxen, diclofenac, and flurbiprofen, as well as these with stearic acid in the axial position. Six Pt(IV) prodrugs

The condensation of 3-formylchromones and 6-amino-5-((3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)amino)-1,3-dimethyl-pyrimidine-2,4(1H,3H)-dione allowed us to synthesize chromone based hybrids containing additional pharmacophores - xanthine and sterically hindered phenol fragments. Novel compounds have been characterized by 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. The molecular structure of compound 2 was determined by single crystal X-ray diffraction studies. Compounds 2-9, 11, 12 exhibit cytotoxic activity against human colon carcinoma cells HCT116 and breast carcinoma cells MCF7 at submicromolar concentrations. Compound 11 containing 6,8-dimethylchromone core has the highest cytotoxicity against tumor cells and lowest at non-tumor fibroblasts - this is leader compound of the obtained series with acceptable in vitro selectivity. Synthesized compounds exhibit antioxidant activity comparable to the reference drug Trolox. Combination of promising antioxidant activity and a selective antitumor cytotoxicity in vitro determines the prospects of these compounds as chemotherapy agents.

Along with bright fluorescence in the near-IR range, heptamethine carbocyanine dyes possess affinity to cancer cells. Thus, these dyes could be utilized as fluorescent labels and vectors for drug delivery as covalent conjugates with cytotoxic compounds. To test the properties, structure-activity relationship, and scope of such conjugates, we synthesized drug-dye dyads of tricarbocyanine dyes with anthracycline drug daunorubicin. We used hydrophilic zwitterionic and hydrophobic positively charged benzoindoline-benzothiazole-based heptamethine dyes as terminal alkyne derivatives and N-acylated or oxime-linked daunorubicin as azido-derivatives. These two alkynes and two azides were coupled to each other by Cu-catalyzed Huisgen-Meldal-Sharpless cycloaddition (click reaction) to afford four conjugates. Molecules based on hydrophobic dyes possess submicromolar cytotoxicity to HCT116 cells. Cytotoxicity, cell penetration, intracellular distribution, apoptosis induction and the effect of antioxidants on toxicity were evaluated. The results show that the structure of the cyanine-anthracycline conjugate (hydrophilicity/hydrophobicity, charge, linker, attachment site) is important for its biological activity, thus, expansion of the chemical space of such conjugates could provide new molecular research tools for diagnostics and therapy.

The efficacy of photodynamic therapy (PDT) strictly depends on the availability of molecular oxygen to trigger the light-induced generation of reactive species. Fluorocarbons have an increased ability to dissolve oxygen and are attractive tools for gas delivery. We synthesized three fluorous derivatives of chlorin with peripheral polyfluoroalkyl substituents. These compounds were used as precursors for preparing nanoemulsions with perfluorodecalin as an oxygen depot. Therefore, our formulations contained hydrophobic photosensitizers capable of absorbing monochromatic light in the long wavelength region and the oxygen carrier. These modifications did not alter the photosensitizing characteristics of chlorin such as the generation of singlet oxygen, the major cytocidal species in PDT. Emulsions readily entered HCT116 colon carcinoma cells and accumulated largely in mitochondria. Illumination of cells loaded with emulsions rapidly caused peroxidation of lipids and the loss of the plasma membrane integrity (photonecrosis). Most importantly, in PDT settings, emulsions potently sensitized cells cultured under prolonged (8 weeks) hypoxia as well as cells after oxygen depletion with sodium sulfite (acute hypoxia). The photodamaging potency of emulsions in hypoxia was significantly more pronounced compared to emulsion-free counterparts. Considering a negligible dark cytotoxicity, our materials emerge as efficient and biocompatible instruments for PDT-assisted eradication of hypoxic cells.

In order to increase the bioavailability of water-insoluble pyropheophorbide-a (PPP-a) methyl ester, its liposomal form is prepared and the physicochemical and photochemical properties of this form are studied. The quantum yield of 1O2 is found to have a bell-shaped dependence on the concentration of PPP-a in the lipid phase of liposomes with the maximum at 31.6 µmol/g of lipids. The IR spectroscopy shows the photoinduced formation of aldehyde groups in the lipid phase of liposomes. The intracellular accumulation of PPP-a is confirmed by confocal microscopy.

Heptamethine carbocyanine dyes possess bright fluorescence in the near IR range and affinity to cancer cells. Thus, these dyes could be utilized as fluorescent labels and vectors for drug delivery in their covalent conjugates with cytotoxic compounds. In this work we synthesized four drug-dye conjugates of tricarbocyanine dyes with anthracycline drug daunorubicin using a CuAAC reaction. Conjugates with hydrophobic dyes possess submicromolar cytotoxicity. Fluorescent imaging revealed significant accumulation of the conjugates in mitochondria, suggesting an enhancement of an additional mechanism of anthracycline cytotoxicity – generation of ROS. The hypothesis was supported by significant reduction of activity of the conjugates in presence of an antioxidant compound.

Copper-containing agents are promising antitumor pharmaceuticals due to the ability of the metal ion to react with biomolecules. In the current study, we demonstrate that inorganic Cu2+ in the form of oxide nanoparticles (NPs) or salts, as well as Cu ions in the context of organic complexes (oxidation states +1, +1.5 and +2), acquire significant cytotoxic potency (2–3 orders of magnitude determined by IC50 values) in combinations with N-acetylcysteine (NAC), cysteine, or ascorbate. In contrast, other divalent cations (Zn, Fe, Mo, and Co) evoked no cytotoxicity with these combinations. CuO NPs (0.1–1 µg/mL) together with 1 mM NAC triggered the formation of reactive oxygen species (ROS) within 2–6 h concomitantly with perturbation of the plasma membrane and caspase-independent cell death. Furthermore, NAC potently sensitized HCT116 colon carcinoma cells to Cu–organic complexes in which the metal ion coordinated with 5-(2-pyridylmethylene)-2-methylthio-imidazol-4-one or was present in the coordination sphere of the porphyrin macrocycle. The sensitization effect was detectable in a panel of mammalian tumor cell lines including the sublines with the determinants of chemotherapeutic drug resistance. The components of the combination were non-toxic if added separately. Electrochemical studies revealed that Cu cations underwent a stepwise reduction in the presence of NAC or ascorbate. This mechanism explains differential efficacy of individual Cu–organic compounds in cell sensitization depending on the availability of Cu ions for reduction. In the presence of oxygen, Cu+1 complexes can generate a superoxide anion in a Fenton-like reaction Cu+1L + O2 → O2−. + Cu+2L, where L is the organic ligand. Studies on artificial lipid membranes showed that NAC interacted with negatively charged phospholipids, an effect that can facilitate the penetration of CuO NPs across the membranes. Thus, electrochemical modification of Cu ions and subsequent ROS generation, as well as direct interaction with membranes, represent the mechanisms of irreversible membrane damage and cell death in response to metal reduction in inorganic and organic Cu-containing compounds.

Complexes of photosensitizers with blood proteins play an essential role in their delivery to the cell, as well as in the efficacy of photodynamic therapy. Biscarbocyanine dye non-covalently binds human serum albumin (HSA), the dissociation constant of the dye with albumin being Kd = (1.7 ± 0.1) × 10-5 M. According to time correlated single photon counting (TCSPC) fluorescence lifetime spectroscopy data, two types of complexes with lifetimes of 1.0 ns and 2.5 ns are formed between the dye and HSA. Confocal fluorescence microscopy has unambiguously shown the penetration of biscarbocyanine into endoplasmic reticulum, lysosomes, mitochondria and nuclei of the cells. The dye demonstrates photocytotoxicity towards the colon carcinoma HCT116 cells with IC50 = 0.3 μM. Hydrophobicity of the polymethine chain and the presence of two positive charges on the dye molecule contribute to the effective binding of the dye with HSA and the penetration into cells. These facts allow considering the biscarbocyanine dye as a promising agent for the photodynamic therapy of cancer.

The reaction of 3-formylchromones and 4-((2-aminophenyl)imino)-2,6-di‑tert-butylcyclohexa-2,5-dienone gave a series of N-substituted benzimidazole derivatives, characterized by 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. The molecular structures of compounds 1 and 4 were determined by single crystal X-ray diffraction studies. Compounds 1–8 exhibit cytotoxic activity against human colon cancer cells HCT116 and breast cancer cells MCF7 at submicromolar concentrations. Compound 6 is more active against tumor cells than non-malignant fibroblasts. Compounds 1, 3, 5 and 7 exhibit antioxidant activity comparable to the reference drug Trolox.

We describe the synthesis and properties of a new composite material based on heparin and MIL-101(Fe) metal-organic framework. The intrinsic instability of MIL-101(Fe) towards hydrolysis enables binding of heparin molecules to the framework structure as is evidenced by DFT calculations and adsorption experiments. The de novo formed heparin-MOF composites showed good biocompatibility in in vitro and demonstrated pronounced anticoagulant activity. The specific interaction between the bioactive molecule and the carrier is critical for the selective degradation of the complex in the body fluids and for the enhanced activity. Hep_MIL-101(Fe) composite could serve as a drug-releasing depot for nanofabrication and to introduce anticoagulant activity to medical devices and biocoatings. Addition of Hep_MIL-101(Fe) to a sol-gel derived thrombolytic matrix allowed the combination of anticoagulant and thrombolytic activities in a single hybrid nanomaterial that could be applied as a bioactive nanocoating for PTFE vein implants.

Background: Hypoxia renders tumor cells refractory to treatment. One way to overcome this problem is the design of drug delivery systems that contain the antitumor agent within an oxygen supply medium. Objective: to evaluate whether the perfluorocarbon liquids (capable of retaining up to 50% v/v amounts of O2 gas) can be tools for delivery of photosensitizers to hypoxic tumors. Method: We synthesized a series of compounds in which fluoroaliphatic or fluoroaromatic moieties were conjugated to the porphyrin ring in meso-positions. Two derivatives were tested as the solutions prepared either from a dimethylformamide stock (‘free’ formulation) or from a perfluorocarbon emulsion in which the photosensitizer is entrapped in the oxygenated medium. Results: In the emulsion the hydrophobic photosensitizer and the gas transporting liquid represented a biocompatible composition. Free formulations or perfluorocarbon emulsions of fluorinated porphyrins evoked little-to-null dark cytotoxicity. In contrast, each formulation triggered cell death upon light activation. Photodamage in the presence of fluorinated porphyrins was achievable not only at normoxic (20.9% O2 v/v) conditions but also in hypoxia (0.5% O2). With new compounds dissolved in the medium the cell photodamage in hypoxia was negligible whereas a significant photodamage was achieved with the emulsions of fluorinated porphyrins. The derivative with the fluoroalkyl substituent was more potent than its structurally close analog carrying the fluoroaryl moiety. Conclusion: Our new fluorinated porphyrin derivatives, especially their emulsions in which the photosensitizer and the oxygenated medium are coupled into one phase, can be perspective for photoelimination of hypoxic tumor cells.

New glycosylated alkyl glycerolipids bearing a cationic group at the C6 position of sugar moiety have been synthesized and tested as potential anticancer drugs. The compounds demonstrated cytotoxicity and selectivity against tumor cells at low micromolar concentration.

A series of novel meso- triazoloporphyrin-carborane conjugates was prepared in good yields via the copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of Zn(II) or Pd(II) 5,10,15,20-tetrakis[4-(2-propargyloxy)-2,3,5,6-tetrafluorophenyl]porphyrin or Zn(II) 5,10,15,20-tetra(p-propargyloxyphenyl)porphyrin with 1-azidomethyl-o-carborane in CH2Cl2. Zinc metalloporphyrins were demetallated under acidic conditions to afford the corresponding free-base triazolo-carborane porphyrins in excellent yields. All new compounds were characterized by MS, NMR and UV–vis spectroscopy and their photophysical properties were studied.

Objective To synthesize a novel chemotype based on the naphthoquinone scaffold with retained cytotoxicity and provisionally low intracellular oxidation potential. Background Derivatives of naphthoquinone, although potent anticancer agents, can exert heart toxicity due to generation of free oxygen species. Methods In this study, we modified the scaffold by replacing one carbonyl group with the oxime moiety. Interestingly, only one carbonyl group in 1-R-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione 2-oxides reacted with hydroxylamine. The spatial structure was determined by X-ray analysis. New compounds were tested for the ability to form stable complexes with double stranded DNA by spectroscopy and molecular docking and to induce death of tumor cell lines and non-malignant counterparts. Results The resulting 1-R-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione 4-oxime 2-oxides were further acylated to produce a series of 1-R-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione 4-(O-acyloxime) 2-oxides. Newly synthesized compounds demonstrated a higher (in submicromolar or low micromolar range) cytotoxic potency against human colon and breast adenocarcinoma cell lines than to non-malignant skin fibroblasts. Spectroscopic measurements revealed that, unlike other classes of quinone derivatives, new naphthotriazoledione oxides did not form stable complexes with double stranded DNA regardless of their fitting to the DNA minor groove (as determined by molecular modeling). Conclusion Thus, our chemical modifications yielded a new chemotype with good cytotoxic properties and yet-to-be-identified intracellular target(s).

A series of novel alkyl cationic glycerolipids with a heterocyclic polar domain have been synthesized. The most reactive compound, rac-N-{4-[(2-ethoxy-3-octadecyloxy)prop-1-yloxycarbonyl]butyl}-N′-ethylimidazolium iodide, at micromolar concentrations induced a delay of the cell cycle in the G1 phase, DNA fragmentation, and the apoptosis of human leukosis cells.

New glycosylated alkyl glycerolipids possessing antitumour activity were synthesized from 2-O-ethyl-1-O-octadecylglycerol, amino alcohols and monosaccharides.