Design and synthesis of vancomycin-functionalized ZnFe2 O4 nanoparticles as an effective antibacterial agent against methicillin-resistant Staphylococcus aureus.

The emergence of antibiotic-resistant bacterial infections is a principal threat to global health. Functionalization of nanomaterial with antibiotics is known as a useful method for increasing the effectiveness of existing antibiotics. In this study, vancomycin-functionalized ZnFe2 O4 nanocomposite (ZnFe2 O4 @Cell@APTES@Van) was synthesized, and its functional groups and particle size were characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, scanning electron microscope, and transmission electron microscopy. The antibacteria activity of the synthesized nanocomposite was evaluated using minimum inhibitory concentration and minimum bactericidal concentration against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). Cytotoxicity assay was done by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide method. Characterization analyses of synthesized nanocomposite confirmed the binding of vancomysin on the surface of ZnFe2 O4 @Cell@APTES. Nanocomposite exhibited an aggregated semi-spherical structure with hydrodynamic radii of ∼382 nm. In vitro antibacterial activity test showed that vancomycin and vancomycin functionalized ZnFe2 O4 have no antibacterial effect against E. coli. S. aureus was sensitive to vancomycin and ZnFe2 O4 @Cell@APTES@Van NPs and ZnFe2 O4 NPs did not improve vancomycin antibacterial activity against these bacteria. MRSA is resistant to vancomycin while ZnFe2 O4 @Cell@APTES@Van NPs was efficient in inhibiting MRSA growth. In summary, this study showed that attachment of vancomycin to ZnFe2 O4 NPs was increased its antibacterial activity against MRSA.

A spectroscopic investigation of the interaction between c-MYC DNA and tetrapyridinoporphyrazinatozinc(II).

The c-MYC gene plays an important role in the regulation of cell proliferation and growth and it is overexpressed in a wide variety of human cancers. Around 90% of c-MYC transcription is controlled by the nuclease-hypersensitive element III1 (NHE III1), whose 27-nt purine-rich strand has the ability to form a G-quadruplex structure under physiological conditions. Therefore, c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Here, the interaction of water-soluble tetrapyridinoporphyrazinatozinc(II) with 27-nt G-rich strand (G/c-MYC), its equimolar mixture with the complementary sequence (GC/c-MYC) and related C-rich oligonucleotide (C/c-MYC) is investigated. Circular dichroism (CD) measurements of the G-rich 27-mer oligonucleotide in 150 mM KCl, pH 7 demonstrate a spectral signature consistent with parallel G-quadruplex DNA. Furthermore, the CD spectrum of the GC rich oligonucleotide shows characteristics of both duplex and quadruplex structures. Absorption spectroscopy implies that the complex binding of G/c-MYC and GC/c-MYC is a two-step process; in the first step, a very small red shift and hypochromicity and in the second step, a large red shift and hyperchromicity are observed in the Q band. Emission spectra of zinc porphyrazine are quenched upon addition of three types of DNA. According to the results of spectroscopy, it can be concluded the dominant binding mode is probably, outside binding and end stacking.

The effect of silymarin (Silybum marianum) on human skin fibroblasts in an in vitro wound healing model.

CONTEXT: Silymarin, a flavonolignan from Silybum marianum (L.) Gaertn. (Asteraceae), has been reported to have antioxidant and anti-inflammatory properties. Therefore, it may be worthwhile to study the effect of silymarin on wound healing. OBJECTIVE: To evaluate the effect of silymarin on human fibroblast cells in an in vitro model of wound healing. MATERIALS AND METHODS: Human fibroblast cells were treated with different concentrations (4.5, 9, 18, 36 µg/mL) of silymarin. The effects of silymarin on cell viability, proliferation, collagen synthesis, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthetase (iNOS) were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-bromo-2'-deoxy-uridine, hydroxyproline analysis and real-time PCR, respectively. The effect of silymarin on cellular antioxidant status was determined by protection against hydrogen peroxide (H2O2)-induced cell injury and free radical scavenging activity (ABTS assay) of the cells. RESULTS: Results of the present study indicate that pretreatment of fibroblast cells with silymarin significantly protected cells against H2O2-induced injury (p < 0.05). After an 18 h treatment of cells with 36 µg/mL silymarin, total antioxidant capacity of cells significantly increased (p < 0.05). Furthermore, pretreatment of human fibroblast cells with silymarin significantly inhibited lipopolysaccharide (LPS)-induced COX-2 mRNA expression (p < 0.001). There was no significant difference in fibroblast proliferation and collagen synthesis between treatment and control groups (p > 0.05). DISCUSSION AND CONCLUSION: Silymarin may be useful as a therapeutic agent for the treatment of cutaneous wounds through its antioxidation and anti-inflammation effects.

Effect of topical application of silymarin (Silybum marianum) on excision wound healing in albino rats.

Silymarin, an extract from Silybum marianum, has been shown to have antioxidant properties. However, there is no scientific report on wound healing activity of the silymarin. The purpose of this study was to evaluate the effect of topical administration of silymarin on excision wound healing in rats. Excision wounds were made on the back of rats. Rats were divided into three groups, as control, vehicle, and treatment. Vehicle and treatment groups received polyethylene glycol and silymarin dissolved in polyethylene glycol, respectively. The control group did not receive any treatment. The wound tissues were removed on 5th, 10th and 15th day for histopathological analysis and total collagen determination by hydroxyproline assay. Results showed that silymarin increased epithelialization and decreased inflammation but did not have any effect on percentage of wound contraction, collagenization and hydroxyproline levels. It was concluded that silymarin can significantly stimulate epithelialization and reduce inflammation in full-thickness wounds in rats.