Platinum(II)-Gadolinium(III) Complexes as Potential Single-Molecular Theranostic Agents for Cancer Treatment

Fabrication, in-silico, in-vitro, and in-vivo characterization of transferrin-targeted micelles containing cisplatin and gadolinium for improved theranostic applications in lung cancer therapy

The targeted delivery of therapeutic and imaging agents is quite challenging in lung cancer therapy. Thus, lung cancer causes high mortality across the world. Herein, we developed TPGS-PF127 micelles containing cisplatin (CDDP) as a model anticancer drug and gadolinium (Gd) as a diagnostic agent by a slightly modified solvent casting method, further, the surface of the micelles was modified using TPGS-transferrin (TPGS-Tf) conjugate to improve targeted delivery of micelles to the lung cancer cells. Prior to this, the binding affinity of Tf over TfR (1E7U) and TfR (1E8W) was investigated with the help of in-silico studies. In-silico results showed good docking scores -7.8 and -7.2 kcal/mol of Tf -ligand towards 1E8W and 1E7U respectively promoting PI3K inhibition. Micelles have shown an average particle size range of 80-200 nm and have shown spherical morphology. The encapsulation efficiency of cisplatin (CDDP) in the CPT, CGPT, and CGPT-Tf micelles ranged from 75.63 % ± 1.58 % to 85.07 % ± 2.65 %. Furthermore, the encapsulation efficiency of gadolinium (Gd) in the CGPT and CGPT-Tf micelles was found to be 67.50 ± 0.32 % and 62.52 ± 0.52 %, respectively. CGPT-Tf micelles exhibited sustained release fashion for CDDP up to 48 h in physiological conditions. In the cytotoxicity study, CGPT-Tf micelles achieved higher cytotoxicity and caused a more antiproliferative effect in A549 cells compared to a commercial CDDP injection (Ciszest 50), after 24 h of treatment. Furthermore, the pharmacokinetic studies have proven the pharmacological effectiveness of developed CGPT-Tf micelles by achieving higher Cmax, Tmax, t1/2, and MRT of CDDP in systemic circulation compared to its counterparts and Ciszest 50. In lung theranostic observations, a higher internalization of Gd was noted in CGPT-TF compared to free Gd. The biochemical studies have proved the biocompatibility of developed micelles formulations by showing no sign of toxicity in the lungs. The developed micelles have great potential to be utilized in treating and diagnosing a wide variety of cancers.

In vitro and in vivo activity of novel platinum(ii) complexes with naphthalene imide derivatives inhibiting human non-small cell lung cancer cells

3 induced NCI-H460 cell apoptosis via inhibition of the telomerase and dysfunction of mitochondria. Remarkably, 3 obviously inhibited NCI-H460 xenograft tumor growth in vivo.

Designing luminescent ruthenium prodrug for precise cancer therapy and rapid clinical diagnosis

The effective design of a targeted drug delivery system could improve the therapeutic efficacy of anticancer drugs by reducing their undesirable adsorption and toxic side effects. Here, an RGD-peptide functionalized and bioresponsive ruthenium prodrug (Ru-RGD) was designed for both cancer therapy and clinical diagnosis. This prodrug can be selectively delivered to cervical tumor sites to enhance theranostic efficacy. The benzimidazole-based ligand of the complex is susceptible to acidic conditions so, after reaching the tumor microenvironment, ligand substitution occurs and the therapeutic drug is released. The deep-red emissions produced by both one-photon and two-photon excitation increases the potential of Ru-RGD for use in the deep tissue imaging of 3D tumor spheroids. The specific accumulation of the Ru prodrug in tumor sites allows for precise tumor diagnosis and therapy in vivo. Luminescence staining of 38 clinical patient specimens shows that Ru-RGD exhibits differences in binding capability between cervical cancer and normal tissue, with a sensitivity of 95% and a specificity of 100%. This study thus provides an approach for the effective design and application of targeted metal complexes in cancer therapy and clinical diagnosis.

On the Antibacterial Activity of Azacarboxylate Ligands: Lowered Metal Ion Affinities for Bis-amide Derivatives of EDTA do not mean Reduced Activity

EDTA is widely used as an inhibitor of bacterial growth, affecting the uptake and control of metal ions by microorganisms. We describe the synthesis and characterisation of two symmetrical bis-amide derivatives of EDTA, featuring glycyl or pyridyl substituents: AmGly₂ and AmPy₂ . Metal ion affinities (logK) have been evaluated for a range of metals (Mg²⁺ , Ca²⁺ , Fe³⁺ , Mn²⁺ , Zn²⁺ ), revealing less avid binding compared to EDTA. The solid-state structures of AmGly₂ and of its Mg²⁺ complex have been determined crystallographically. The latter shows an unusual 7-coordinate, capped octahedral Mg²⁺ centre. The antibacterial activities of the two ligands and of EDTA have been evaluated against a range of health-relevant bacterial species, three Gram negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and a Gram positive (Staphylococcus aureus). The AmPy₂ ligand is the only one that displays a significant inhibitory effect against K. pneumoniae, but is less effective against the other organisms. AmGly₂ exhibits a more powerful inhibitory effect against E. coli at lower concentrations than EDTA (<3 mm) or AmPy₂ , but loses its efficacy at higher concentrations. The growth inhibition of EDTA and AmGly₂ on mutant E. coli strains with defects in outer-membrane lipopolysaccharide (LPS) structures has been assessed to provide insight into the unexpected behaviour. Taken together, the results contradict the assumption of a simple link between metal ion affinity and antimicrobial efficacy.

A novel fluorescent probe (dtpa-bis(cytosine)) for detection of Eu(III) in rare earth metal ions

In this paper, a novel fluorescent probe, dtpa-bis(cytosine), was designed and synthesized for detecting europium (Eu³⁺) ion. Upon addition of Eu³⁺ ions into the dtpa-bis(cytosine) solution, the fluorescence intensity can strongly be enhanced. Conversely, adding other rare earth metal ions, such as Y³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Yb³⁺ and Lu³⁺, into dtpa-bis(cytosine) solution, the fluorescence intensity is decreased slightly. Some parameters affecting the fluorescence intensity of dtpa-bis(cytosine) solution in the presence of Eu³⁺ ions were investigated, including solution pH value, Eu³⁺ ion concentration and interfering substances. The detection mechanism of Eu³⁺ ion using dtpa-bis(cytosine) as fluorescent probe was proposed. Under optimum conditions, the fluorescence emission intensities of Eu^III-dtpa-bis(cytosine) at 375nm in the concentration range of 0.50×10^-5mol∙L^-1-5.00×10^-5mol∙L^-1 of Eu³⁺ ion display a better linear relationship. The limit of detection (LOD) was determined as 8.65×10^-7mol∙L^-1 and the corresponding correlation coefficient (R²) of the linear equation is 0.9807. It is wished that the proposed method could be applied for sensitively and selectively detecting Eu³⁺ ion.

Versatile Types of MRI-Visible Cationic Nanoparticles Involving Pullulan Polysaccharides for Multifunctional Gene Carriers

Owing to the low cytotoxicity and excellent biocompatibility, polysaccharides are good candidates for the development of promising biomaterials. In this paper, a series of magnetic resonance imaging (MRI)-visible cationic polymeric nanoparticles involving liver cell-targeting polysaccharides were flexibly designed for multifunctional gene delivery systems. The pullulan-based vector (PuPGEA) consisting of one liver cell-targeting pullulan backbone and ethanolamine-functionalized poly(glycidyl methacrylate) (denoted by BUCT-PGEA) side chains with abundant hydroxyl units and secondary amine was first prepared by atom transfer radical polymerization. The resultant cationic nanoparticles (PuPGEA-GdL or PuPGEA-GdW) with MRI functions were produced accordingly by assembling PuPGEA with aminophenylboronic acid-modified Gd-DTPA (GdL) or GdW10O36(9-) (GdW) via the corresponding etherification or electrostatic interaction. The properties of the PuPGEA-GdL and PuPGEA-GdW nanoparticles including pDNA condensation ability, cytotoxicity, gene transfection, cellular uptake, and in vitro and in vivo MRI were characterized in details. Such kinds of cationic nanoparticles exhibited good performances in gene transfection in liver cells. PuPGEA-GdW demonstrated much better MRI abilities. The present design of PuPGEA-based cationic nanoparticles with the liver cell-targeting polysaccharides and MRI contrast agents would shed light on the exploration of tumor-targetable multifunctional gene delivery systems.

Cyclometalated Ruthenium(II) Anthraquinone Complexes Exhibit Strong Anticancer Activity in Hypoxic Tumor Cells

Hypoxia is the critical feature of the tumor microenvironment that is known to lead to resistance to many chemotherapeutic drugs. Six novel ruthenium(II) anthraquinone complexes were designed and synthesized; they exhibit similar or superior cytotoxicity compared to cisplatin in hypoxic HeLa, A549, and multidrug-resistant (A549R) tumor cell lines. Their anticancer activities are related to their lipophilicity and cellular uptake; therefore, these physicochemical properties of the complexes can be changed by modifying the ligands to obtain better anticancer candidates. Complex 1, the most potent member of the series, is highly active against hypoxic HeLa cancer cells (IC50 =0.53 μM). This complex likely has 46-fold better activity than cisplatin (IC50 =24.62 μM) in HeLa cells. This complex tends to accumulate in the mitochondria and the nucleus of hypoxic HeLa cells. Further mechanistic studies show that complex 1 induced cell apoptosis during hypoxia through multiple pathways, including those of DNA damage, mitochondrial dysfunction, and the inhibition of DNA replication and HIF-1α expression, making it an outstanding candidate for further in vivo studies.