DNA Binding and Antitumor Activity of α-Diimineplatinum(II) and Palladium(II) Dithiocarbamate Complexes

The two water-soluble designed platinum(II) complex, [Pt(Oct-dtc)(bpy)]NO3 (Oct-dtc = Octyldithiocarbamate and bpy = 2,2′ -bipyridine) and palladium(II) complex, [Pd(Oct-dtc)(bpy)]NO3, have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR, 1H NMR, and electronic spectra studies. Studies of antitumor activity of these complexes against human cell tumor lines (K562) have been carried out. They show Ic50 values lower than that of cisplatin. The complexes have been investigated for their interaction with calf thymus DNA (CT-DNA) by utilizing the electronic absorption spectroscopy, fluorescence spectra, and ethidium bromide displacement and gel filtration techniques. Both of these water-soluble complexes bound cooperatively and intercalatively to the CT-DNA at very low concentrations. Several binding and thermodynamic parameters are also described

Biophysical and computational comparison on the binding affinity of three important nutrients to β-lactoglobulin: folic acid, ascorbic acid and vitamin K3

<p>Small globular protein, β-lactoglobulin (βLG), which has significant affinity toward many drugs, is the most abundant whey protein in milk. In this study, the interaction of βLG with three important nutrients, ascorbic acid (ASC), folic acid (FOL), and vitamin K3 (VK3) was investigated by spectroscopic methods (UV–visible and fluorescence) along with molecular docking technique. The results of fluorescence measurements showed that studied nutrients strongly quenched βLG fluorescence in static (FOL and ACS) or static–dynamic combined quenching (VK3) mode. The values of binding constants (<i>K</i>_βLG-ASC ~ 4.34 × 10⁴ M⁻¹, <i>K</i>_βLG-FOL ~ 1.67 × 10⁴ M⁻¹and K_βLG-VK3 ~ 13.49 × 10⁴ M⁻¹ at 310 K) suggested that VK3 and FOL had stronger binding affinity toward βLG than ASC. Thermodynamic analysis indicated that hydrophobic interactions are the major forces in the stability of FOL–βLG complex with enthalpy- and entropy-driving mode while, hydrogen bonds and van der Waals interactions play a major role for βLG–ASC and βLG–VK3 associations. The results of 3D fluorescence FT-IR and UV–Visible measurements indicated that the binding of above nutrients to βLG may induce conformational and micro-environmental changes of protein. Also, there is a reciprocal complement between spectroscopic techniques and molecular docking modeling. The docking results indicate that the ASC, FOL, and VK3 bind to residues located in the subdomain B of βLG. Finally, this report suggests that βLG could be used as an effective carrier of above nutrients in functional foods.</p

3D Bioprinting of Polycaprolactone-Based Scaffolds for Pulp-Dentin Regeneration: Investigation of Physicochemical and Biological Behavior

In this study, two structurally different scaffolds, a polycaprolactone (PCL)/45S5 Bioglass (BG) composite and PCL/hyaluronic acid (HyA) were fabricated by 3D printing technology and were evaluated for the regeneration of dentin and pulp tissues, respectively. Their physicochemical characterization was performed by field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), contact angle, and compressive strength tests. The results indicated that the presence of BG in the PCL/BG scaffolds promoted the mechanical properties, surface roughness, and bioactivity. Besides, a surface treatment of the PCL scaffold with HyA considerably increased the hydrophilicity of the scaffolds which led to an enhancement in cell adhesion. Furthermore, the gene expression results showed a significant increase in expression of odontogenic markers, e.g., dentin sialophosphoprotein (DSPP), osteocalcin (OCN), and dentin matrix protein 1 (DMP-1) in the presence of both PCL/BG and PCL/HyA scaffolds. Moreover, to examine the feasibility of the idea for pulp-dentin complex regeneration, a bilayer PCL/BG-PCL/HyA scaffold was successfully fabricated and characterized by FESEM. Based on these results, it can be concluded that PCL/BG and PCL/HyA scaffolds have great potential for promoting hDPSC adhesion and odontogenic differentiation

A novel Pd(II) CNO pincer complex of MR (methyl red): Synthesis, crystal structure, interaction with human serum albumin (HSA): In vitro and molecular docking

The C-H activation of methyl red (MR) (MR = 2-[4-(dimethylamino)phenyl]diazenylbenzoic acid) was achieved by reaction with Pd(OAc)2 under mild conditions. Metalation occurred at the ortho-position of the (dimethylamino)phenyl group in methyl red and the cyclometalated CNO pincer complex was obtained in good yield. The molecular structure shows that MR forms 6,5-fused chelate rings at the Pd(ii) center. Interaction of the pincer complex with human serum albumin (HSA) has been studied by fluorescence spectroscopy and circular dichroism. Fluorescence quenching at different temperatures was analyzed using the classical Stern-Volmer equation, and a dynamic quenching mechanism was proposed. Energy resonance transfer between HSA and 1aⲠwas examined according to Förster's non-radiative energy transfer theory. A distance of about 5.06 à between the complex and Trp214 (HSA) was obtained. Docking studies showed that the binding pocket of subdomain IIA of HSA is the preferable pincer complex binding site

Multi-spectroscopic and electrochemical approaches of the interaction between a new binuclear agent and DNA

Multi-spectroscopic and electrochemical approaches of the interaction between a new binuclear agent and DN