Surface modification of super paramagnetic iron oxide nanoparticles via milk casein for potential use in biomedical areas.

Super paramagnetic iron oxide nanoparticles (SPIONs) have proved that they have tremendous potential to use in various biomedical applications. But the surface of pure iron oxide nanoparticles so fast oxidized, that is a major drawback for biomedical applications. Covered SPIONs have good surface activity. Therefore, the first goal was to synthesize the naked SPIONs. Then we modified with 3-Aminopropyltriethoxysilane (APTES) and trichlorotriazine (TCT). Several techniques measurements were used for characterization the size and special features of naked SPIONs and TCT modified SPIONs. These results show that the SPIONs were synthesized. After that the SPIONs are coated with casein and indicate that there is an interaction between them. Moreover, we have investigated magnetic properties and anticancer effects of casein-coated SPIONs. Therefore, we showed casein could be used to increase the biocompatibility of the surface of SPIONs. At the end, we show that bonding of dipyridamole (DIP) to the surface of casein-coated SPIONs have good magnetite properties for targeted drug delivery. We find that the release of DIP by casein-coated SPIONs-DIP was sensitive to pH. Both release curves in pH 5.5 and 7.4 showed the release of DIP by ß-casein coated SPIONs-DIP better than α-casein coated SPIONs-DIP. The cell culture studies of the casein-coated SPIONs-DIP provide good anticancer effects against both breast and prostate cancer cell lines. Here, we propose a simple and inexpensive chemical method for preparation of highly biocompatible core-shell SPIONs and binding of drug for using in targeted drug delivery system. Communicated by Ramaswamy H. Sarma.

Spectrophotometric-chemometrics study of the effect of solvent composition and temperature on the spectral shape and shift of copper and nickel phthalocyanines in different aqueous-nonaqueous mixed solvents.

Phthalocyanines (Pcs) are green-blue colored aromatic macrocyclic compounds used extensively in the dyeing industry. The assembly phenomenon for dye molecules is directly traceable by most of the spectroscopic methods. In this investigation, the monomer-dimer equilibria of copper and nickel phthalocyanines tetra sulfonic acid tetrasodium salts (CuPcTS, NiPcTS) have been investigated by spectrophotometric and chemometrics methods in binary mixtures of H2O-DMSO and H2O-CH3CN. The dimerization constants, (KD), enthalpies and entropies of CuPcTS and NiPcTS have been calculated by studying the UV-Vis spectra at different concentrations of dyes (10-6 to 10-4molL) and in the temperature range 298-343 K and in some samples up to 353 K by multivariate curve resolution (mcr) methods. By increasing the temperature, the value of KD decreases. The inverse temperature dependence of KD (van't Hoff equation) was used for determination of ΔH 0 and ΔS 0and following that ΔG 0of the dimerization reactions. As a result, upon aggregation, an increase in the intensity of the new shoulder at (~600 nm) and the Q-band at (662-670 nm) and concomitant decrease of the dimer band at (630-624 nm) are observed for all of the samples in different solvents composition. Therefore, the H-dimer type of these pigments was notable, in studied binary solvents. The effect of the solvent composition, concentration dye, and temperature on the spectral responses, the exciton parameters and concentration distribution diagrams of the two pigments were studied and discussed. The density functional theory (DFT) calculations were done in the aqueous and gas phase that they were included the HOMO-LUMO energies and the simulated UV-Vis spectrum. These calculations were beneficial for studying the UV-Vis spectrum of it in the aqueous phase for checking experimental data.

Toxicity of Fe2 O3 nanoparticles on human blood lymphocytes.

Magnetic nanoparticles (NPs) are used to a large extent in the targeted delivery of therapeutic agents. In this study, we aimed to investigate the possible toxicity of Fe2 O 3 NPs on human cells, including blood lymphocytes. We isolated blood lymphocytes from healthy humans using Ficoll polysaccharide and subsequently by gradient centrifugation. Then, the toxicity parameters, including cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, cellular glutathione (GSH) level, mitochondrial and lysosomal damage, were measured in blood lymphocytes after exposure to Fe 2 O 3 NPs. Our results indicated that Fe 2 O 3 NPs significantly (dependent on concentration) reduced the cell viability, and the IC 50 was determined to be 1 mM. With increasing concentrations, we found that Fe 2 O 3 NPs-induced cell toxicity was associated with a significant increase in intracellular ROS and loss of mitochondrial membrane potential and lysosomal membrane leakiness. Consequently, these NPs at different concentrations affect GSH level and cause oxidative stress in human lymphocytes.

Milk caseins as useful vehicle for delivery of dipyridamole drug.

The interaction of bovine milk α- and ß-caseins as an efficient drug carrier system with Dipyridamole (DIP) was investigated using spectroscopy and molecular docking studies at different temperatures (20-37 °C). FTIR, CD, and fluorescence spectroscopy methods demonstrated that α- and ß-caseins interact with DIP molecule mainly via hydrophobic and hydrophilic interactions and change in secondary structure of α- and ß-caseins. DIP showed a higher quenching efficiency and binding constant of α-casein than ß-casein. There was only one binding site for DIP and it was located on the surface of the protein molecule. The thermodynamic parameters of calculation showed that the binding process occurs spontaneously and demonstrated that α- and ß-caseins provide very good binding and entrapment to DIP via hydrogen bonds, Van der Waals forces, and hydrophobic interactions. Fluorescence resonance energy transfer, synchronous fluorescence spectroscopy, and docking study showed that DIP binds to the Trp residues of α- and ß-casein molecules with short distances. Docking study showed that DIP molecule made several hydrogen bonds and van der Waals interactions with α- and ß-caseins. The study of cell culture and micellar solubility of DIP demonstrated α- and ß-caseins relatively the same helping in delivery of DIP. Milk α- and ß-caseins are considered as a useful vehicle for the solublization and stabilization of DIP in aqueous solution at natural pH.

Intermolecular interaction of nickel (ii) phthalocyanine tetrasulfonic acid tetrasodium salt with bovine serum albumin: A multi-technique study.

The interaction of nickel (II) phthalocyanine tetrasulfonic acid tetrasodium salt with bovine serum albumin (BSA) has been investigated by combination of fluorescence, UV-vis absorption, Fourier transform infrared (FT-IR), and circular dichorism (CD) spectroscopies as well as through molecular docking. Fluorescence quenching and absorption spectra were investigated as a mean for estimating the binding parameters. Analysis of fluorescence quenching data at different temperatures was performed in order to specify the thermodynamics parameters for interactions of phthalocyanine complex with BSA. According to experimental data it was suggested that phthalocyanine had a significant binding affinity to BSA and the process was entropy driven. Based on the results of molecular docking it was indicated that the main active binding site for this phthalocyanine complex is site I in subdomain IIA of BSA. The results provide useful information for understanding the binding mechanism of anticancer drug-albumin and gives insight into the biological activity and metabolism of the drug in blood.

An Investigation on intermolecular interaction between Bis(indolyl)methane and HSA and BSA using multi technique methods.

Bis(indolyl)methane (BIM) as one of the main active components of anticancer and antibacterial drugs is applied in medicinal and extensive area of chemistry. In this research, interaction of human and bovine serum albumins as drug carriers with BIM was investigated using spectroscopy methods and molecular modeling study. The fluorescence quenching measurements at the range of 293-310 K revealed that the quenching mechanisms for human and bovine serum albumins are static and dynamic processes, respectively. The results of quenching study were used to calculate thermodynamic parameters [Formula: see text] which indicated that the binding process occurs spontaneously and demonstrated that human and bovine serum albumins provide very good binding via hydrogen bonds, van der Waals forces, and hydrophobic interactions. Förster energy transfer measurements, synchronous fluorescence spectroscopy, and docking study showed BIM binds to the Trp residues of human and bovine serum albumin molecules in short distances. Docking study showed that BIM molecule has two hydrogen bonds and several van der Waals contacts with human and bovine serum albumins. Results of FT-IR and CD spectroscopy demonstrated that serum albumins interact with BIM molecule mainly via hydrophobic and hydrophilic interactions and the secondary structure of serum albumins are changed.

Spectroscopy and Molecular Modeling Study on Binding of Nickel Phthalocyanine to Human Serum Albumin.

The interaction of nickel tetra sulfunated phthalocyanine( NiTSPc) with human serum albumin (HSA), in 20 mM phosphate buffer pH 7.4 was investigated using advanced techniques including fluorescence, synchronous fluorescence, Fourier transform infrared (FT-IR), circular dichroism (CD) spectroscopy and molecular docking. The fluorescence quenching measurements showed a single binding site on HSA for NiTSPc with the binding constant (K_b) value equals to 1.26×106 at 25°C. The results showed that quenching mechanism of HSA by NiTSPc was of dynamic type. The results from FTIR and CD spectroscopies demonstrated that NiTSPc binds to amino acid residues of the main polypeptide chain in protein destroying the hydrogen bonding network. The corresponding thermodynamic parameters were then calculated by analysis of fluorescence data using van't Hoff plot. These data indicated that driving force for interaction was mainly hydrophobic in nature and the process was entropy driven. The information obtained from CD, FT-IR and synchronous fluorescence spectroscopies revealed that both microenvironment and conformation of HSA was changed. Molecular docking study confirmed the binding mode obtained by experimental data.