Fish Sperm DNA Research Articles

A mononuclear Ni(II) complex with 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine: DNA- and BSA-binding and anticancer activity against human breast carcinoma cells

DNA- and BSA-binding properties of a mononuclear Ni(II) complex, [Ni(dppt)2Cl2] (dppt=5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine), have been investigated under physiological conditions. The interaction of the complex with the fish sperm DNA (FS-DNA) has been studied by UV–Vis absorption, thermal denaturation, viscosity measurement, competitive DNA-binding studies with ethidium bromide (EB) by fluorescence, and gel electrophoresis technique. The experimental results indicate that the complex interacts with DNA by intercalative binding mode. The competitive study with ethidium bromide (EB) shows that the complex competes for the DNA-binding sites with EB and displaces the DNA-bound EB molecule. The interactions of the dppt ligand and the complex with BSA have been studied by UV–Vis absorption and fluorescence spectroscopic techniques. The values of Kb for the BSA–dppt and the BSA–complex systems at room temperature were calculated to be 0.14×104M−1 and 0.32×105M−1, respectively, indicating that the complex has stronger tendency to bind with BSA than the dppt ligand. The quenching constants (Ksv), binding constants (Kbin), and number of binding sites (n) at different temperatures, as well as the binding distance (r) and thermodynamic parameters (ΔH°, ΔS° and ΔG°) have been calculated for the BSA–dppt and the BSA–complex systems. The cytotoxicities of the dppt ligand and the complex have been also tested against the human breast adenocarcinoma (MCF-7) cell line using the MTT assay. The results indicate that the dppt ligand and the complex display cytotoxicity against human breast cancer cell lines (MCF-7) with the IC50 values of 17.35μM and 13.00μM, respectively. It is remarkable that the complex can introduce as a potential anticancer drug.

Ultrasensitive Detection of Mitochondrial DNA Mutation by Graphene Oxide/DNA Hydrogel Electrode

Ultrasensitive detection of nucleic acid has attracted considerable attention recently in academic research and clinic diagnostics. Current approaches for DNA analysis involve complicated or expensive processes for labeling and often yield a high detection limit. In this study, a hydrogel electrode prepared from graphene oxide and fish sperm DNA is used for label−free mitochondrial DNA detection by impedimetric approach. The hydrogel has a bionic structure containing rich water and natural biomolecule fish sperm DNA that would benefit the adsorption and hybridization of DNA. Graphene oxide is a semiconductor and its conductivity can be improved by doping negatively charged DNA molecules. The result shows that the conductivity and impedance change of hydrogel electrode could be tuned by its length and component. The linear range for DNA detection by the optimized hydrogel is from 1.0 × 10−9 to 1.0 × 10−20 M with a detection limit of 1.0 × 10−20 M. The result is ascribed to the bionic structure and tunable conductivity of hydrogel electrode. The hydrogel electrode has been used to detect the real DNA samples from patients of ovarian cancer with satisfactory results.

Alkenyl-substituted titanocene dichloride complexes: Stability studies, binding and cytotoxicity

Four alkenyl-substituted titanocene dichloride complexes [Ti(η5-C5H5){η5-C5H4(CMeR(CH2CH2CHCH2))}Cl2] (R = Me (8), Ph (9)) and [Ti(η5-C5H5){η5-C5H3(CMeR(CH2CH2CHCH2))(SiMe3)}] (R = Me (10), Ph (11)) have been synthesized and characterized.The cytotoxic activity of 8–11 has been tested against human tumour cell lines from four different tissue origins [8505C (anaplastic thyroid cancer), DLD-1 (colon cancer), FaDu (head and neck cancer), A2780 (ovarian cancer) and A549 (lung carcinoma)] and compared with those of the reference complexes [Ti(η5-C5H5)2Cl2] and cisplatin. The majority of the studied titanocene compounds are more active than the reference complex [Ti(η5-C5H5)2Cl2] indicating that the presence of alkenyl substituents leads to an increase in the cytotoxic activity. In addition, the presence of a trimethylsilyl group on the cyclopentadienyl ring also leads to an increase in the cytotoxic activity of 10 with respect to 8. The contrary is observed for 9 and 11 (except on the DLD-1 cell line) with 9 (without –SiMe3) being more active than 11 (with –SiMe3). However, all synthesized complexes, exhibited lower cytotoxic activity than cisplatin.Stability and binding studies based on cyclic voltammetry and UV–visible spectroscopy have been carried out in order to explore possible interactions between titanocene derivatives and various intracellular molecules, such as the nitrogenous bases cytosine and thymine, the nucleotides adenosine and guanosine, and single-strand fish sperm DNA (FS-DNA). These experiments have allowed us to construct models to examine the interactions and action mechanisms of titanocene complexes inside the cells. In addition, this is one of the first studies on the interactions of titanocene derivatives with DNA fragments using cyclic voltammetry.

Electrochemical Behaviors of Resveratrol and Its Interaction with DNA

AbstractElectrochemical behavior of resveratrol was studied in Britton‐Robinson (B‐R) buffer solution (pH = 4.0) at glassy carbon electrode (GCE) using cyclic voltammetry (CV). Resveratrol showed an irreversible anodic peak at 0.570 V which was involving one electron and one proton. Also, the interaction of resveratrol with double‐stranded fish sperm DNA was investigated by linear sweep voltammetry (LSV) and UV‐vis spectra. The results showed that peak potentials shifted to more positive value and peak currents decreased in electrochemical experiment and the maximum absorption decreased with red shift in UV‐vis spectra experiment with the addition of DNA, indicating the resveratrol interacted with DNA by intercalating into the double helix of DNA. Besides, the binding of resveratrol with DNA, analyzed in terms of the cooperative Hill model, yields the association constant Ka = 3.18 × 105 and a Hill coefficient m = 1.06.

Coupling isotachophoresis with affinity chromatography for rapid and selective purification with high column utilization, part 2: experimental study.

We present an experimental study of coupling of isotachophoresis (ITP) and affinity chromatography (AC) to effect rapid, selective purification with high column utilization and high resolution. We provide a detailed protocol for performing ITP-AC and describe the design of a buffer system to perform sequence specific separation of nucleic acids. We describe the synthesis and functionalization of our affinity substrate, poly(glycidyl methacrylate-co-ethylene dimethacrylate) porous polymer monolith (GMA-EDMA PPM). This substrate allows easy immobilization of affinity probes, is nonsieving (even to macromolecules), and exhibits negligible nonspecific binding. We demonstrate ITP-AC with 25 nt, Cy5 labeled DNA target and a DNA probe and study the spatiotemporal dynamics using epifluorescence imaging. We make qualitative and quantitative comparisons between these data and the model presented in the first part of this two-paper series. We vary the target concentration from 1 pg μL–1 to 100 pg μL–1 and ITP velocity over the range of 10–50 μm s–1, and thereby explore over 4 orders of magnitude of scaled target amount. We observe very good agreement between predictions and experimental data for the spatiotemporal behavior of the coupled ITP and affinity process, and for key figures of merit, including scaled capture length and maximum capture efficiency. Lastly, we demonstrate that the resolution of ITP-AC increases linearly with time and purify 25 nt target DNA from 10 000-fold higher abundance background (contaminating) genomic fish sperm DNA. We perform this capture from 200 μL of sample in under 1 mm column length and within <10 min.

Synthesis and in vitro cytotoxic effect of 6-amino-substituted 11H- and 11Me-indolo[3,2-c]quinolines

A series of 6-amino-11H- indolo[3,2-c]quinoline derivatives with various substituents on the quinoline ring were synthesized. A methyl group introduced to N-11 of the intermediate 4 to elaborate novel analog 7. The cytotoxic effect of these 6-amino-substituted 11H- and 11-methyl-indolo[3,2-c]quinoline derivatives in vitro were tested against MV4-11 (human leukemia), A549 (non-small cell lung cancer) and HCT116 (colon cancer) and BALB/3T3 (normal murine fibroblasts). All the N-11 methylated compounds significantly increased the cytotoxicity. Compound 7p was most active with the IC50 value of 0.052 μM against the MV4-11 cell line, and also exhibited a selective activity against A549, HCT116 and BALB/3T3 cell line, with the respective IC50 values of 0.112, 0.007 and 0.083 μM, which were higher or comparable to those of the anticancer drug doxorubicin HCl. The binding constants of 5g and 7h to salmon fish sperm DNA were also evaluated using UV–vis absorption spectroscopy, indicating intercalation binding with constants of 1.05 × 106 L/mol and 4.84 × 106 L/mol.

DNA- and BSA-binding studies and anticancer activity against human breast cancer cells (MCF-7) of the zinc(II) complex coordinated by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine

Binding studies of a mononuclear zinc(II) complex, [Zn(dppt)2Cl2] (dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine), with DNA and bovine serum albumin (BSA) have been investigated under physiological conditions. The binding properties of the complex with fish sperm DNA (FS-DNA) have been investigated by UV–Vis absorption, thermal denaturation, competitive DNA-binding studies with ethidium bromide (EB) by fluorescence, and gel electrophoresis techniques. The competitive study with (EB) shows that the complex can displace EB from the DNA-EB system and compete for the DNA-binding sites with EB, which is usually characteristic of the intercalative interaction of compounds with DNA. The value of the fluorescence quenching constant (Ksv) was obtained as 3.1×104M−1, indicating that this complex shows a high quenching efficiency and a significant degree of binding to DNA.Moreover, the intercalative binding mode has also been verified by the results of UV–Vis absorption, thermal denaturation and gel electrophoresis. The value of Kb at room temperature was calculated to be 1.97×105M−1, indicating that the complex possesses strong tendency to bind with DNA. This value is very greater than to the values obtained for other zinc(II) complexes. The interaction of the complex with BSA has been studied by UV–Vis absorption, fluorescence and circular dichroism (CD) spectroscopic techniques. The results indicate that the complex has a quite strong ability to quench the fluorescence of BSA and the binding reaction is mainly a static quenching process. The quenching constants (KSV), the binding constants (Kb), the number of binding sites at different temperatures, the binding distance between BSA and the complex (r), and the thermodynamic parameters (ΔHo, ΔSo and ΔGo) between BSA and the complex were calculated. The complex exhibits good binding propensity to BSA showing relatively high binding constant values. The positive ΔHo and ΔSo values indicate that the hydrophobic interaction is main force in the binding of the complex to BSA. Moreover, to evaluate the anticancer properties, the cytotoxicity of the complex has been tested against the human breast adenocarcinoma (MCF-7) cell lines using the MTT assay. The results indicate that the parent complex displays cytotoxicity against human breast cancer cell lines (MCF-7) with an IC50 value of 10.44μM. It is remarkable that the complex can introduce as a potential anticancer drug.

Synthesis, crystal structures, in vitro DNA binding, antibacterial and cytotoxic activities of new di- and polynuclear silver(I) saccharinate complexes with tertiary monophosphanes

Four new silver(I) saccharinate (sac) complexes, [Ag(μ-sac)(PPh3)]2 (1), [Ag(μ-sac)(PPh2Cy)]2 (2), [Ag(μ-sac)(PPhCy2)]2 (3) and [Ag(μ-sac)(PCy3)]n (4), where PPh3=triphenylphosphane, PPh2Cy=cyclohexyldiphenylphosphane, PPhCy2=dicyclohexylphenylphosphane and PCy3=tricyclohexylphosphane, have been synthesized and fully characterized by elemental analysis, IR, NMR, ESI-MS and single crystal X-ray diffraction. Fluorescence ethidium bromide displacement indicate that all complexes bind to fish sperm (FS) DNA by intercalation with binding constants (KA) of 29.1±0.26×105M−1 for 1, 2.54±0.12×105M−1 for 2, 2.42±0.08×105M−1 for 3, 0.19±0.03×105M−1 for 4. The relative viscosities of the FS-DNA solutions increase with increasing of the complex concentration, providing strong evidence for the intercalation mode. The gel electrophoresis assay further confirms their binding with the pBR322 plasmid DNA. The MIC values of the silver(I) complexes are generally higher than those of AgNO3 and silver sulfadiazine, but 1 presents a promising activity against Salmonellatyphimurium and Staphylococcusaureus. All complexes are highly cytotoxic on human lung carcinoma (A549) and human breast adenocarcinoma (MCF-7) cell lines with IC50 values ranging from 0.82 to 3.13μM.

Mineralization of DNA into nanoparticles of hydroxyapatite

Encapsulation of DNA into hydroxyapatite (HAp) has been investigated using a rational approach that involves computer simulation and experimental techniques. The temporal evolution of the radial distribution functions derived from atomistic molecular dynamics simulations of Ca(2+), PO4(3-) and OH(-)-containing aqueous solutions in the presence and absence of B-DNA has been used to conclude that the backbone of the double helix acts as a template for HAp growth. More specifically, results reveal the formation of calcium phosphate clusters at the first stages of the simulations, which subsequently re-organize to nucleate HAp. This effect is produced in the absence and, especially, presence, of DNA indicating that the biomolecules do not inhibit but even promote mineral growth. Furthermore, computer simulations suggest that the diffusion of the OH(-) anions through the inorganic solution is the limiting step for the nucleation of the biomineral. Nanocapsules and crystalline nanorods of HAp containing DNA molecules inside have been prepared by mixing solutions containing Ca(2+) and PO4(3-) ions with fish sperm DNA at high pH. The dimensions and morphology of such nanostructures have been examined by transmission electron microscopy, while the characterization of the biomineral has been focused on the identification of DNA inside HAp using infrared, X-ray photoelectron and UV-vis spectroscopies, as well as gel electrophoresis. The biominerals reported in this work are important for biomedical applications requiring the protection of DNA from aggressive environmental conditions.

In vitro DNA binding studies of the sweetening agent saccharin and its copper(II) and zinc(II) complexes

The interactions of fish sperm DNA (FS-DNA) with the sodium salt of sweetener saccharin (sacH) and its copper and zinc complexes, namely [M(sac)2(H2O)4]·2H2O (M=CuII or ZnII) were studied by using UV–Vis titration, fluorometric competition, thermal denaturation, viscosity and gel electrophoresis measurements. The intrinsic binding constants (Kb) obtained from absorption titrations were estimated to be 2.86 (±0.06)×104M−1 for Na(sac), 6.67 (±0.12)×104M−1 for Cu-sac and 4.01 (±0.08)×104M−1 for Zn-sac. The Cu-sac complex binds to FS-DNA via intercalation with a KA value of 50.12 (±0.22)×104M−1 as evidenced by competitive binding studies with ethidium bromide. Moreover, competition experiments with Hoechst 33258 are indicative of a groove binding mode of Na(sac) and Zn-sac with binding constants of 3.13 (±0.16)×104M−1 and 5.25 (±0.22)×104M−1, respectively. The spectroscopic measurements indicate a moderate DNA binding affinity of Na(sac) and its metal complexes. The suggested binding modes are further confirmed by the thermal denaturation and viscosity measurements. In addition, Cu-sac and Zn-sac show weak ability to damage to pBR322 supercoiled plasmid DNA.

Di- and polynuclear silver(I) saccharinate complexes of tertiary diphosphane ligands: synthesis, structures, in vitro DNA binding, and antibacterial and anticancer properties

A series of new silver(I) saccharinate (sac) complexes, [Ag2(sac)2(μ-dppm)H2O]·H2O (1), {[Ag2(μ-sac)2(μ-dppe)]·3H2O·CH2Cl2} n (2), [Ag2(μ-sac)2(μ-dppp)] n (3), and [Ag(sac)(μ-dppb)] n (4) [dppm is 1,1-bis(diphenylphosphino)methane, dppe is 1,2-bis(diphenylphosphino)ethane, dppp is 1,3-bis(diphenylphosphino)propane, and dppb is 1,4-bis(diphenylphosphino)butane], have been synthesized and characterized by C, H, N elemental analysis, IR spectroscopy, (1)H NMR, (13)C NMR, and (31)P NMR spectroscopy, electrospray ionization mass spectrometry, and thermogravimetry-differential thermal analysis. Single-crystal X-ray studies show that the diphosphanes act as bridging ligands to yield a dinuclear complex (1) and one-dimensional coordination polymers (2 and 4), whereas the sac ligand adopts a μ2-N/O bridging mode in 2, and is N-coordinated in 1 and 4. The interaction of the silver(I) complexes with fish sperm DNA was investigated using UV-vis spectroscopy, fluorescence spectroscopy, and agarose gel electrophoresis. The binding studies indicate that the silver(I) complexes can interact with fish sperm DNA through intercalation, and complexes 1 and 3 have the highest binding affinity. The gel electrophoresis assay further confirms the binding of the complexes with the pBR322 plasmid DNA. The minimum inhibitory concentrations of the complexes indicate that complex 1 exhibits very high antibacterial activity against standard bacterial strains of Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus, being much higher than those of AgNO3, silver sulfadiazine, ciprofloxacin, and gentamicin. Moreover, complexes 1-3 exhibit very high cytotoxic activity against A549 and MCF-7 cancer cell lines, compared with AgNO3 and cisplatin. The bacterial and cell growth inhibitions of the silver(I) complexes are closely related to their DNA binding affinities.

The meloxicam complexes of Co(II) and Zn(II): Synthesis, crystal structures, photocleavage and in vitro DNA-binding

Two neutral mononuclear complexes of Co(II) and Zn(II) with the non-steroidal anti-inflammatory drug meloxicam (H2mel, 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxammide-1,1-dioxide), [Co(Hmel)2(EtOH)2] (1), and [Zn(Hmel)2(EtOH)2] (2), were synthesized and characterized by elemental analysis, IR and UV–Vis spectroscopy and their solid-state structures were studied by single-crystal diffraction. The complexes have a distorted octahedral geometry around the metal atom. The experimental data indicate that the meloxicam acts as a deprotonated bidentate ligand (through the amide oxygen and the nitrogen atom of the thiazolyl ring) in the complexes, and a strong intramolecular hydrogen bond between the amide N–H function and the enolate O atom stabilizes the ZZZ conformation of meloxicam ligands. Absorption, fluorescence spectroscopy and cyclic voltammetry have been used to investigate the binding of the complexes with fish sperm DNA (FS-DNA). Additionally, the photocleavage studies have been also used to investigate the binding of the complexes with plasmid DNA. The interaction of the complexes with DNA was monitored by a blue shift and hyperchromism in the UV–Vis spectra attributed to an electrostatic binding mode. A competitive study with ethidium bromide (EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. The experimental results show that the complexes can cleave pUC57 plasmid DNA.

A glassy carbon electrode modified with poly(eriochrome black T) for sensitive determination of adenine and guanine

A thin film of poly(eriochrome black T) was deposited on the surface of glassy carbon electrode by cyclic voltammetry, and this system is shown to enable the sensitive determination of adenine (A) and guanine (G). Scanning electron microscopy, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy were carried out to characterize the film which exhibits excellent electrocatalytic activity toward the oxidation of A and G in 0.1 M phosphate buffer solution (pH 4.0). Square wave voltammetry reveals an oxidation peak at 1084 mV whose current is linearly related to the concentration of A in the range from 0.05 to 1.00 μM. The oxidation peak for G occurs at 788 mV, and its current is linearly related to the concentration of G in the range from 0.025 to 1.00 μM. The detection limits are 0.017 μM for A and 0.008 μM for G (at S/N = 3), respectively. The modified electrode displays good reproducibility and selectivity for the determination of A and G. The sensor was applied to quantify A and G in fish sperm DNA with satisfactory results.

Enantioseparation of chiral ofloxacin using biomacromolecules

Natural biomacromolecules including bovine serum albumin (BSA), calf thymus DNA (ct-DNA) and fish sperm DNA (fs-DNA) were studied as the free chiral selectors to separate R- and S-ofloxacin enantiomers from racemic ofloxacin, combined with ultrafiltration and subsequent crystallization. First, the interactions between chiral ofloxacin and biomacromolecules including BSA, ct-DNA, and fs-DNA were investigated using circular dichroism and fluorescence spectroscopy. BSA exhibited stereoselective adsorption towards R-ofloxacin at pH 9.0 with an enantioselectivity of 1.23, while ct-DNA showed enantiospecific interaction with S-enantiomer with the selectivity of 1.70 at pH 5.0. One single-stage adsorption by BSA provides an enantiomeric excess in the permeate (e.e. p ) of 14% in S-enantiomer, and five-stage operations enhance the chiral resolution to reach the e.e.p value of 44%. R-enantiomer with an e.e. p of −26% can be obtained through one single-stage adsorption by using ct-DNA, and −85% can be reached by five-stage operations. Enantiomeric mixtures with the intial e.e. of 44% (S-) can be upgraded to 95% (S-) through subsequent crystallization. This programmable process of adsorption and desorption using BSA or ct-DNA as chiral selectors can be successfully applied to produce the enantiomers with highly optical purity.

DNA Binding and Cleavage Studies of Two Palladium(II) Saccharinate Complexes with Terpyridine

The aim of the present study is to investigate DNA binding interactions of two highly cytotoxic palladium(II) saccharinate (sac) complexes with 2,2':6',2″-terpyridine (terpy), [Pd(sac)(terpy)](sac)·4H(2)O (1) and [PdCl(terpy)](sac)·2H(2)O (2). UV-Vis spectroscopy, fluorescence spectroscopy, thermal denaturation, viscosity, and gel electrophoresis measurements were employed to study binding properties of the two complexes with Fish Sperm (FS) DNA. The interaction of the palladium(II) complexes with FS-DNA was monitored by hypochromism in the UV-Vis spectra. The binding constants (Kb) obtained from absorption titrations were estimated to be 1.0 (±0.05)×10(5) M(-1) for 1 and 2.0 (±0.22)×10(5) M(-1) for 2. Competitive binding studies with ethidium bromide have shown that both complexes strongly bind to FS-DNA, and the apparent binding constant (Kapp) calculated from emission studies was 2.0×10(6) M(-1) for each complex. Fluorescence Scatchard plots demonstrated that the palladium(II) complexes act as dual-function metallointercalators and bind to FS-DNA by both intercalation and coordination. On addition of the two complexes, significant increases in both viscosity and melting temperature of FS-DNA solutions further support the binding mode of these complexes. Gel electrophoresis assay demonstrates that both complexes efficiently cleavage the supercoiled plasmid 8454: pCMV-VSV-G DNA to its open circular form.

Synthesis, crystal structures, DNA binding and cytotoxicity of two novel platinum(II) complexes containing 2-(hydroxymethyl)pyridine and pyridine-2-carboxylate ligands

Two new platinum(II) complexes, trans-[Pt(2-mpy)2]·4H2O (1) and [PtCl(2-pyc)(2-hmpy)]·H2O (2), where 2-hmpy=2-(hydroxymethyl)pyridine, 2-mpy=deprotonated 2-hmpy and 2-pyc=pyridine-2-carboxylate, have been synthesized and characterized by elemental analysis, IR, NMR, and X-ray crystallography. The DNA binding affinities of these complexes for Fish Sperm DNA (FS-DNA) were investigated using fluorescence, viscosity, thermal denaturation and gel electrophoresis measurements. Fluorescence analysis indicates that complex 1 binds to DNA by a single intercalative mechanism, while complex 2 exhibits two types of interactions such as intercalation and covalent binding. Gel electrophoresis assay demonstrates ability of the complexes to cleavage the supercoiled pBR322 plasmid DNA. The in vitro cytotoxicities of both complexes were preliminarily evaluated and the cytotoxicity of complex 1 against the human lung cancer cells (H1299) is similar to oxaliplatin, but higher than transplatin and carboplatin.

Nanosheet-assembled hierarchical nanostructures of hydroxyapatite: surfactant-free microwave-hydrothermal rapid synthesis, protein/DNA adsorption and pH-controlled release

In this paper, a surfactant-free rapid microwave-assisted hydrothermal synthesis of hydroxyapatite nanosheet-assembled flower-like hierarchical nanostructures (NFHNs) is reported. The effects of the experimental conditions on the morphology and crystal phase of the product are investigated. A possible formation mechanism of hydroxyapatite NFHNs is proposed. The morphology of the product can vary from flower-like to polyhedra by adjusting the microwave heating temperature. The protein and DNA adsorption properties of the as-prepared hydroxyapatite NFHNs are studied. The loading capacities of the as-prepared hydroxyapatite NFHNs for bovine serum albumin (BSA), hemoglobin (Hb) and fish sperm DNA are determined to be 165, 164 and 112 mg g−1, respectively. The protein release process is conducted at different pH values (pH 7.2, 5.5 and 4.8) in phosphate buffer saline (PBS), and the pH-controlled protein release behavior has been found. Thus, the as-prepared hydroxyapatite NFHNs are promising for protein drug delivery applications.

Synthesis, characterization, interaction with DNA and cytotoxicity of Pd(ii) and Pt(ii) complexes containing pyridine carboxylic acid ligands

Four metal complexes [Pd(L(1))Cl(2)·2H(2)O] (1), [Pt(L(1))Cl(2)·2H(2)O] (2), [Pd(L(2))Cl(2)·H(2)O] (3) and [Pt(L(2))Cl(2)·H(2)O] (4) (L(1) = 2,2'-bipyridyl-5,5'-dicarboxylic acid, L(2) = 2,2'-bipyridyl-4,4'-dicarboxylic acid) have been synthesized under hydrothermal conditions and fully characterized by IR and (1)H-NMR spectra, elemental analysis, and X-ray single crystal diffraction analysis. Interactions of these complexes with fish sperm DNA (FS-DNA) were investigated using UV-Vis absorption and fluorescence spectroscopic methods. Further insight was brought by quantum chemistry calculations by means of G03 package and taking B3LYP functional Lanl2dz Gen basis set. Agarose gel electrophoresis run on pBR322 plasmid DNA gave proof that all four complexes exhibit efficient DNA cleavage. Complexes 1-4 manifested cytotoxic specificity and a significant cancer cell inhibitory rate. Independent apoptosis tests under the light microscope, performed on hematoxylin-eosin stained HeLa cells, evidenced morphological changes induced by all the complexes.

Trans-Dichloridopalladium(II) and platinum(II) complexes with 2-(hydroxymethyl)pyridine and 2-(2-hydroxyethyl)pyridine: Synthesis, structural characterization, DNA binding and in vitro cytotoxicity studies

Four trans-palladium(II)- and trans-platinum(II)-chlorido complexes, trans-[PdCl2(2-hmpy)2] (1), trans-[PtCl2(2-hmpy)2] (2), trans-[PdCl2(2-hepy)2] (3) and trans-[PtCl2(2-hepy)2] (4) (2-hmpy = 2-(hydroxymethyl)pyridine and 2-hepy = 2-(2-hydroxyethyl)pyridine), have been synthesized and characterized by elemental analysis, IR, NMR, and X-ray diffraction. The binding properties of these complexes with fish sperm DNA (FS-DNA) were investigated by UV titration, viscosity, thermal denaturation and electrophoresis measurements. The complexes can bind to FS-DNA and complex 4 exhibits the highest binding constant. Gel electrophoresis assay demonstrates that all the complexes can cleave the pCMV-βgal plasmid DNA to a different degree. The cytotoxic activities of the complexes were tested against four different cancer cell lines. In general, the platinum(II) complexes are more effective than the isostructural palladium(II) complexes. Complex 4 shows high anticancer activity, compared to transplatin, cisplatin, carboplatin and oxaliplatin.

Spectroscopic Study on the Interaction of Pyronine Y with Nucleic Acids and Its Analytical Application

ABSTRACT The interaction of pyronine Y (PY) with nucleic acids was studied by resonance Rayleigh scattering (RRS) for nucleic acid detection. The enhanced RRS intensity of nucleic acids reacted with PY was proportional to the concentration of nucleic acids in the ranges of 27.0–625 ng ml−1 for fish sperm DNA, 39.0–500 ng ml−1 for calf thymus DNA, and 59.0–375 ng ml−1 for yeast RNA. The limits of determination were 0.2 ng ml−1 for fish sperm DNA, 0.6 ng ml−1 for calf thymus DNA, and 0.7 ng ml−1 for yeast RNA. The method had been successfully applied to the quick determination of nucleic acids in synthetic and natural samples.