Mesut Karahan

Synthesis, characterization, and assessment of cytotoxic, antiproliferative, and antiangiogenic effects of a novel procainamide hydrochloride-poly(maleic anhydride-co-styrene) conjugate

Poly(maleic anhydride-co-styrene) (MAST) was synthesized by a free-radical polymerization reaction. A bioactive molecule, procainamide hydrochloride (PH), was then conjugated to MAST. The conjugation product was named as MAST/PH. Structural characterization of MAST and MAST/PH was carried out by Fourier Transform Infrared and Nuclear Magnetic Resonance spectroscopy. Their molecular weights were determined by size-exclusion chromatography. A mechanism was then suggested for the conjugation reaction. The results of the cytotoxicity assay, employing a mouse fibroblast cell line (L929), indicated that MAST/PH had no cytotoxicity at concentrations 62 μg mL−1 (p > 0.05). Antiproliferative activities of MAST/PH and PH were determined by the BrdU cell proliferation ELISA assay, using C6 and HeLa cell lines. In the experiment, two anticancer chemotherapy drugs, cisplatin and 5-fluorouracil, were included as positive control. Antiproliferative activity results demonstrated that MAST/PH yielded the highest suppression profile (approximately 42%) at 20 μg/ml, while free PH exerted the same activity at 100 μg/ml. Interestingly, both MAST/PH and PH suppressed the proliferation of only one of the cell lines, C6 cells. Both cisplatin and 5-fluorouracil yielded approximately 60% antiproliferative activity on C6 cells at 20 and 100 μg/ml concentrations. Antiangiogenic capacity of both MAST and MAST/PH was also investigated by using the chicken chorioallantoic membrane assay. Results obtained indicated that while MAST/PH could be included into the category of good antiangiogenic substances, the activity score of MAST was within the weak category.

Synthesis of microwave-assisted poly(methyl vinyl ether-co-maleic anhydride)-bovine serum albumin bioconjugates

Abstract The water-soluble poly(methyl vinyl ether-co-maleic anhydride) copolymer-bovine serum albumin bioconjugates were synthesized in the presence of 1-ethyl-3-(3-dimetilamino-propyl) carbodiimide hydrochloride as cross-linking agents via microwave-assisted and conventional methods and characterized by size-exclusion chromatography and high-performance liquid chromatography. According to size-exclusion chromatography and high-performance liquid chromatography results, the bioconjugates synthesized in the microwave-assisted method are more stable and efficient than the conventional method. The reaction time is shortened from 17 hours to 15 minutes by means of the microwave-assisted method.

Immobilization of glutaminase enzyme from Hypocria jecorina on polyacrylic acid: preparation and biochemical characterization

Abstract L-glutaminase enzyme produced from Hypocrea jecorina pure culture and polyacrylic acid (PAA) in the presence Cu+ ions were composed the ternary complex at pH 7. The properties of free and immobilized enzyme were defined. The effect of various factors such as pH, temperature, heat, and storage stability on immobilized enzyme were investigated. The properties of immobilized enzyme were investigated and compared to those of free enzyme. Optimum pH and temperature of both enzyme were determined to be 8.0 and 50°C, respectively. Kinetic parameters of the immobilized enzyme (Km and Vmax values) were also determined as 0.38 mM of the Km and 10.9 U/L of the Vmax. No drastic change was observed in the Km and Vmax values. Thermal and storage stability experiments were carried out. The thermal stability studies indicated that the immobilization process tends to stabilize the enzyme.

Investigation of metal–polyelectrolyte complex toxicity

Water-soluble binary and ternary copper complexes of polyelectrolytes were synthesized, and the toxicity of these complexes was tested in mouse fibroblast cell line (L929) in vitro. Both the binary and ternary complexes were prepared at the ratio of 0.4 mole copper(II) ions per monomer of acrylic acid and 0.5 mole copper(II) ions per monomer of methyl vinyl ether maleic anhydride, furthermore at the ratio of 1 and 2 mole bovine serum albumin per mole of polyacrylic acid and poly(methyl vinyl ether-co-maleic anhydride), respectively. Compared to binary copper(II)–polyelectrolyte complexes, these ternary complexes have been determined to be of least toxicity.

The Formation of Polycomplexes of Poly(Methyl Vinyl Ether-Co-Maleic Anhydride) and Bovine Serum Albumin in the Presence of Copper Ions

Abstract The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride) (PMVEMA) with copper ions and with bovine serum albumin (BSA) in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II), the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II)/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II)-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.

Radiation shielding parameters of some antioxidants using Monte Carlo method

In this paper, radiation shielding parameters such as mass attenuation coefficients and half value layer (HVL) of some antioxidants are investigated using MCNPX (version 2.4.0). The validation of the generated MCNPX simulation geometry for antioxidant structures is provided by comparing the results with standard WinXcom data for radiation mass attenuation coefficients of antioxidants. Very good agreement between WİNXCOM and MCNPX was obtained. The results from the validated geometry were used to calculate the shielding parameters of different antioxidants. The radiation attenuation properties of each antioxidant were compared with each other. The results showed that, on average, the highest and the lowest radiation mass attenuation coefficients were observed on hesperidin and delphinidin chloride, respectively. It can be concluded that Monte Carlo simulation is a strong tool and an alternate method where experimental investigations are not possible and a standard simulation setup can be used in further studies for different biological structures. It can also be concluded that the obtained results from this study are very useful for radiology and radiotherapy applications where antioxidants are frequently used.