Enhancement of Tumor Cell Immunogenicity and Antitumor Properties Derived from Platinum-Conjugated Iron Nanoparticles.

From chemistry design to clinical application, several approaches have been developed to overcome platinum drawbacks in antitumoral therapies. An in-depth understanding of intracellular signaling may hold the key to the relationship of both conventional drugs and nanoparticles. Within these strategies, first, nanotechnology has become an essential tool in oncotherapy, improving biopharmaceutical properties and providing new immunomodulatory profiles to conventional drugs mediated by activation of endoplasmic reticulum (ER) stress. Secondly, functional proteomics techniques based on microarrays have proven to be a successful method for high throughput screening of proteins and profiling of biomolecule mechanisms of action. Here, we conducted a systematic characterization of the antitumor profile of a platinum compound conjugated with iron oxide nanoparticles (IONPs). As a result of the nano-conjugation, cytotoxic and proteomics profiles revealed a significant improvement in the antitumor properties of the starting material, providing selectivity in certain tumor cell lines tested. Moreover, cell death patterns associated with immunogenic cell death (ICD) response have also been identified when ER signaling pathways have been triggered. The evaluation in several tumor cell lines and the analysis by functional proteomics techniques have shown novel perspectives on the design of new cisplatin-derived conjugates, the high value of IONPs as drug delivery systems and ICD as a rewarding approach for targeted oncotherapy and onco-immunotherapies.

Comprehensive and systematic characterization of multi-functionalized cisplatin nano-conjugate: from the chemistry and proteomic biocompatibility to the animal model.

BACKGROUND: Nowadays, nanoparticles (NPs) have evolved as multifunctional systems combining different custom anchorages which opens a wide range of applications in biomedical research. Thus, their pharmacological involvements require more comprehensive analysis and novel nanodrugs should be characterized by both chemically and biological point of view. Within the wide variety of biocompatible nanosystems, iron oxide nanoparticles (IONPs) present mostly of the required features which make them suitable for multifunctional NPs with many biopharmaceutical applications. RESULTS: Cisplatin-IONPs and different functionalization stages have been broadly evaluated. The potential application of these nanodrugs in onco-therapies has been assessed by studying in vitro biocompatibility (interactions with environment) by proteomics characterization the determination of protein corona in different proximal fluids (human plasma, rabbit plasma and fetal bovine serum),. Moreover, protein labeling and LC-MS/MS analysis provided more than 4000 proteins de novo synthetized as consequence of the nanodrugs presence defending cell signaling in different tumor cell types (data available via ProteomeXchanges with identified PXD026615). Further in vivo studies have provided a more integrative view of the biopharmaceutical perspectives of IONPs. CONCLUSIONS: Pharmacological proteomic profile different behavior between species and different affinity of protein coating layers (soft and hard corona). Also, intracellular signaling exposed differences between tumor cell lines studied. First approaches in animal model reveal the potential of theses NPs as drug delivery vehicles and confirm cisplatin compounds as strengthened antitumoral agents.

Functional insights into the cellular response triggered by a bile-acid platinum compound conjugated to biocompatible ferric nanoparticles using quantitative proteomic approaches.

At present, bioferrofluids are employed as powerful multifunctional tools for biomedical applications such as drug delivery, among others. The present study explores the cellular response evoked when bile-acid platinum derivatives are conjugated with bioferrofluids by testing the biological activity in osteosarcoma (MG-63) and T-cell leukemia (Jurkat) cells. The aim of this work is to evaluate the biocompatibility of a bile-acid platinum derivative conjugated with multi-functional polymer coated bioferrofluids by observing the effects on the protein expression profiles and in intracellular pathways of nanoparticle-stimulated cells. To this end, a mass spectrometry-based approach termed SILAC has been applied to determine in a high-throughput manner the key proteins involved in the cellular response process (including specific quantitatively identified proteins related to the vesicular transport, cellular structure, cell cycle, biosynthetic process, apoptosis and regulation of the cell cycle). Finally, biocompatibility was evaluated and validated by conventional strategies also (such as flow cytometry, MTT, etc.).

Enhanced cytotoxic activity of bile acid cisplatin derivatives by conjugation with gold nanoparticles.

This article explores the potential cytotoxic activity of bile-acid cisplatin derivatives like bisursodeoxycholate(ethylenediamine)platinum(II), PtU2, when conjugated with gold nanoparticles, being a promising alternative to cisplatin in the treatment of cancer due to their lower toxicity. For our purpose we analyzed the intracellular delivery ability of these compounds after conjugation with 20-nm gold nanoparticles (PtU2-AuNPs) in the MG63 (osteosarcoma) cell line. Same platinum uptake after incubation with PtU2 and PtU2-AuNPs-derivatives is associated with a higher cytotoxic activity in case of the platinum-gold nanoparticle conjugate, the overall IC50 of PtU2 being reduced more than 10 fold for these new conjugates. When conjugated with gold nanoparticles, this bile-acid derivative is more efficient than the platinum compound alone in terms of their cytotoxic activity.

Platinum complexes for multi-parametric assays using microarray systems.

Here, we present a two novel fluorescent dyes ethylenediaminechlorocholylglycinateplatinum(II), [Pt(CG)Cl(en)] complex 1 and bisursodeoxycholate(ethylenediamine)platinum(II), [Pt(UDC)(2)(en)] complex 2 based on well-known cis-platin chemistry. These platinum complexes contain cholylglycinate (CG) and ursodeoxycholate (UDC) as ligands. These compounds enable qualitative detection of double-helix DNA and quantitative detection (from pg to µg). These novel compounds have absorption and emission spectra in a difference range as the common ones (for example: cyanine dyes such as Cy3, Cy5, Cy7,…); therefore, it could allow the multi-parametric detection of DNA arrays, incrementing the capacity of experimental performance per one single array. As a consequence, it will increase the amount of data info obtained per chip. The combination of the intrinsic property of this compounds with the optical properties in different fluorescence channels, can allow introducing a new molecule with a wide range of possible applications in DNA arrays.

Bisursodeoxycholate(ethylenediamine)platinum(II): a new autofluorescent compound. Cytotoxic activity and cell cycle analysis in ovarian and hematological cell lines.

The present paper describes for the first time an intrinsic fluorescent square-planar platinum(II) complex carrying two ursodeoxycholate ligands ([Pt(UDC)2(en)], where UDC(-) = ursodeoxycholate), that emits at room temperature once free in solution. Kinetic studies were carried out in aqueous solution and in the presence of different NaCl concentrations: 4 mM (similar to cytoplasmic concentration) and 150 mM (similar to plasmatic concentration). This novel compound was synthesized from a [PtCl2(en)] complex and shows increased cytotoxic activity against both resting and cycling HeLa cells, with no toxicity for cell lines derived from neoplastic haematopoietic cells.

Thiourea, triazole and thiadiazine compounds and their metal complexes as antifungal agents.

Many currently available antifungal and antibacterial agents have undesirable toxic effects, and a wide spread use of these drugs has lead to rapid development of drug resistant strains which are the leading cause for treatment failure in both clinical and agricultural applications. The present article provides a synopsis of recent progress in investigations of new classes of antifungal compounds: disubstituted aliphatic and aromatic thioureas, triazole and thiazine compounds which act as ligands for transition metals. Antifungal effects of these compounds and selected metallic complexes versus representative plant pathogenic fungi are reviewed.

Intrinsically fluorescent cytotoxic cisplatin analogues as DNA marker molecules.

Two square planar derivatives of Pt(en)Cl(2) with intrinsic fluorescence in aqueous solution at room temperature, with quantum yields (Phi) 0.11 and 0.10, respectively, have been synthesized and characterized as [Pt(en)(CG)Cl] (Complex 1) and [Pt(en)(CG)(2)] (Complex 2) (en = ethylenediamine, CG = cholylglycinate). Complexes 1 and 2 exchange just one ligand (chloride or cholylglycinate, respectively) when reacted with water or 5'-GMP to give the same chemical species. After reaction with DNA oligonucleotides or DNA plasmids, they show enhanced emission in the visible region, which lasts for long periods of time and makes them potentially useful DNA marker molecules. Incubation with nucleated blood cells followed by microscopic analyses revealed that they enter the cells within minutes of exposure, selectively stain the DNA, and persist after more than 48 h of exposure. Complexes 1 and 2 display cell cycle phase-independent cytotoxic activity against cisplatin-resistant CHO (Chinese hamster ovarian) tumor cells, with an early onset of their effects. Their slightly different biological effects, as compared to cisplatin, are considered to be linked to the bile acids and their vector properties and to the preferential formation of monoadducts.

N-benzoyl-N'-alkylthioureas and their complexes with Ni(II), Co(III) and Pt(II) - crystal structure of 3-benzoyl-1-butyl-1-methyl-thiourea: activity against fungi and yeast.

The thiourea derivatives of N-butylmethylamine (3-benzoyl-1-butyl-1-methyl-thiourea) (1), N-ethylisopropylamine (3-benzoyl-1-ethyl-1-isopropyl-thiourea) (2) and the corresponding complexes of 1 and 2 with Ni(II), Co(III) and Pt(II) have been synthesized. The compounds obtained were characterized by elemental analysis, spectroscopic methods (FT-IR, UV-Vis and NMR) and mass spectrometry. Compound 1, crystallized in the triclinic space group. The antifungal activities of compounds 1 and 2 and their corresponding complexes against the fungus Penicillium digitatum and against the yeast Saccharomyces cerevisiae were investigated. In general, fungal growth inhibition was higher with compound 1 and its complexes than with compound 2, except for the Co(III) complex of 2.

New organotropic compounds. Synthesis, characterization and reactivity of Pt(II) and Au(III) complexes with bile acids: DNA interactions and 'in vitro' anticancer activity.

Based on the ability of bile acids to vectorialize the cytostatic activity of other agents, we have designed and synthesized a new series of platinum and gold complexes. These compounds were studied and characterized by elemental analysis, FT-IR, FAB(+)/MS, 1H, 13C and 195Pt NMR, UV-Vis spectroscopy and conductivity measurements in solution, among other techniques. Kinetic studies carried out in aqueous solution and in the presence of different NaCl concentrations: 4 mM (similar to cytoplasmic concentration), 150 mM (similar to plasmatic concentration). The effects on the electrophoretic mobility of the pUC18 plasmid, the DNA denaturation temperature, and ethidium bromide (EtBr) binding to DNA were studied. The complexes are able to inter-react with DNA to inhibit DNA synthesis and hence, to reduce cell proliferation. The complexes were evaluated for in vitro cytostatic activity against human colon adenocarcinoma, mouse hepatoma, human hepatoma, mouse leukemia, etc. The antitumor effect of some of the compounds prepared was similar to that of cisplatin. However, other compounds had lower cytostatic activity. This different behavior can be accounted for by the structure/activity relationship (SAR), although other factors, such as uptake and the different kinetic behavior in solution, may be responsible for these differences.

Thiourea derivatives and their nickel(II) and platinum(II) complexes: antifungal activity.

We have synthesized two thiourea derivatives of methyl anthranilate (1, 2) and their complexes with nickel (3) and platinum(II) (4). We have also prepared the complexes of nickel(II) with two benzoylthiourea derivatives (5, 6). The obtained compounds were characterized by elemental analysis, spectroscopic methods (FT-IR, UV-vis, NMR), mass spectrometry and thermal analysis. Compound 1, C(20)H(23)N(3)O(2)S, crystallizes in monoclinic space group P21/n, with Z=4, and unit cell parameters, a=8.8042(4) A, b=7.6608(3) A, c=28.834(2) A, alpha=gamma=90 degrees, beta=90.94(1) degrees. Compound 2, C(20)H(21)N(3)O(3)S, crystallizes in monoclinic space group P21/c, with Z=4, and unit cell parameters, a=7.7345(4) A, b=8.6715(4) A, c=29.113(2) A, alpha=gamma=90 degrees, beta=90.67(1) degrees. Compound 5, C(24)H(30)N(4)NiO(2)S(2), crystallizes in monoclinic space group P21/n, with Z=4, and unit cell parameters, a=10.4317(8) A, b=18.517(2) A, c=13.299(1) A, alpha=gamma=90 degrees, beta=104.53(1) degrees. Compound 6, C(25)H(28)Cl(2)N(4)NiO(4)S(2), crystallizes with a molecule of CH(2)Cl(2) in triclinic space group P-1, with Z=2, and unit cell parameters, a=10.362(1) A, b=11.849(2) A, c=12.536(2) A, alpha=90.04(2) degrees, beta=84.73(1) degrees, gamma=113.43(2) degrees. Compounds 1 and 2 show antifungal activity against the major pathogens responsible for important plant diseases (Botrytis cinerea, Colletotrichum fragariae, Fusarium oxysporum and Phoma betae). The antifungal activity is practically the same for morpholine and ethyl derivatives.