Surface characterization and antibacterial efficiency of well-ordered TiO2 nanotube surfaces fabricated on titanium foams.

Titanium (Ti)-based implants are not compatible enough due to their bio-inert character, insufficient antibacterial capabilities and stress-shielding problem for dental and orthopaedic implant applications. Thus, this work focused to fabricate, analyze and improve antibacterial properties titanium dioxide (TiO2) nanotube array surfaces on Ti foam by anodic oxidation (AO) process. The well-ordered nanotube arrays with approximately 75 nm were successfully fabricated at 40 V for 1 h on Ti foams. Ti and O were observed as major elements on AO-coated Ti foam surfaces. In addition, the existence of TiO2 structure was proved on AO-coated foam Ti surfaces. For potential dental and orthopedic implant application, in vitro antibacterial properties were investigated versus Staphylococcus aureus and Escherichia coli. For both bacteria, antibacterial properties of TiO2 nanotube surface were greater than bare Ti foam. The bacterial inhibition versus Staphylococcus aureus and Escherichia coli of TiO2 nanotube surfaces are improved as 53.3% and 69.4% compared to bare Ti foam.

Characterization and investigation of biological properties of silver nanoparticle-doped hydroxyapatite-based surfaces on zirconium.

The infections leading to failed implants can be controlled mainly by metal and metal oxide-based nanoparticles. In this work, the randomly distributed AgNPs-doped onto hydroxyapatite-based surfaces were produced on zirconium by micro arc oxidation (MAO) and electrochemical deposition processes. The surfaces were characterized by XRD, SEM, EDX mapping and EDX area and contact angle goniometer. AgNPs-doped MAO surfaces, which is beneficial for bone tissue growth exhibited hydrophilic behaviors. The bioactivity of the AgNPs-doped MAO surfaces is improved compared to bare Zr substrate under SBF conditions. Importantly, the AgNPs-doped MAO surfaces exhibited antimicrobial activity for E. coli and S. aureus compared to control samples.

Determination of biological activity of Carduus lanuginosus: an endemic plant in Turkey.

The genus Carduus is traditionally used in the Anatolian folk medicine for treating various diseases. Therefore, the enzyme inhibiting potential, antioxidant-antimicrobial activity, and phytochemical profile of Carduus lanuginosus extracts were investigated. The analysis of phenolic compounds was carried out by using RP-HPLC for the chemical characterization of methanol extract. The total polyphenols, total phenolic and flavonoid contents, antioxidant activity (ABTS and DPPH assay), α-amylase, and α-glucosidase inhibition activities were determined using colorimetric methods. Moreover, the antimicrobial activity was examined using the disc diffusion and microdilution methods. The ethylacetate extract was found to have the highest flavonoid and phenolic content. The water and hexane extracts showed strong enzyme inhibitory activity against the α-amylase and α-glucosidase. The methanol extract was found to contain high concentration of chlorogenic acid. The hexane and ethylacetate extracts showed to have significant MIC values on Enterococcus faecium. In conclusion, the extracts of C. lanuginosus might have a significant potential for the use as a natural pharmaceutical agent.

Antibacterial, antioxidant and enzyme inhibition activity capacities of Doronicum macrolepis (FREYN&SINT): An endemic plant from Turkey.

In the present study, the antioxidant, enzyme inhibition (α-amylase, α-glucosidase, and cholinesterase) and antimicrobial (MIC) activities of three different solvent (ethanol, methanol, or ethyl acetate) extracts of stem, root, and flower of Doronicum macrolepis plant were investigated. In addition to this, the chemical composition and the antimicrobial activity of the essential oil were determined. Antioxidant activity was detected using ABTS and DPPH assays. Antimicrobial activity evaluated by microdilution method against to nineteen microorganisms. Also, enzyme inhibition activities were determined by colorimetric methods. Essential oil of the plant extracted by hydrodistilation and characterized using GC/MS. The antioxidant properties of the flower were determined to be higher than those of the other segments of this plant. Moreover, the total phenolic and flavonoid contents were also found to be higher in the flower parts. The highest enzyme inhibition activity was observed to be α-amylase (221.54 mmol ACAE/g extract) in flower ethylacetate extract, α-glucosidase (15.32 mmol ACAE/g extract) in flower ethanol extract, and cholinesterase (AChE: 2.4 and BChE: 22.35 mg GALE/g extract) in stem ethylacetate extract. Besides them, the antimicrobial activity of the essential oil was found to be higher than the extracts. It showed a high level of inhibition especially on E. coli at 4 µg/ml concentration. Moreover, remarkable inhibition was observed for two candida strains tested. In conclusion, the results suggest that, because of its bioactivity including the antioxidant, antimicrobial, and enzyme inhibition properties, the D. macrolepis can be accepted as a promising and natural source for the industrial applications. The present study is the first study, in which the bioactive components and the antioxidant, antimicrobial, and enzyme inhibition properties of endemic D. macrolepis plant were determined.

An assessment of phenolic profiles, fatty acid compositions, and biological activities of two Helichrysum species: H. plicatum and H. chionophilum.

In the present study, we aimed to search and compare the biological activities of the ethanol (EtOH), methanol (MeOH), and ethylacetate (EtOAc) solvent extracts of the flower, stem, and root parts of two Helichrysum plants (H. chionophilum (Hc) and H. plicatum subsp. plicatum (Hp)). The antioxidant properties were determined by using (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The enzyme inhibitory effects of the extracts were investigated on butyrylcholinesterase (BChE), acetylcholinesterase (AChE), α-glucosidase, and α-amylase. Palmitic acid (C 16:0) was also determined as major fatty acids in the tested oils (31.21%-67.68%). In both plants, it was found that the EtOAc extracts of the flowers had a strong antioxidant and enzyme inhibitory effect. In conclusion, the results obtained in the present study showed that H. chionophilum and H. plicatum can be seen as a promising source for the natural bioactive compounds that can be used in therapeutic applications. PRACTICAL APPLICATIONS: The members of the genus Helichrysum have been widely taken for therapeutic purposes in traditional medicine as well as food. In this context, we investigated the chemical characterization and biological activities of two Helichrysum species extracts (H. chionophilum and H. plicatum subsp. plicatum). Antioxidant capacity, enzyme inhibition and anti-microbial effects were tested for biological activities. Chemical characterization was identified by high performance liquid chromatography (HPLC) (for phenolic) and gas chromatography-flame ioanization detector (GC-FID) (for fatty acids). Based on our findings, the species may be valuable for designing novel food products.

Temporal classification and mapping of non-polyadenylated transcripts of an invertebrate iridovirus.

The temporal expression of the 54 Chilo iridescent virus (CIV) virion protein genes was investigated by combining drug treatments that inhibit protein or DNA synthesis and an RT-PCR strategy particularly suitable for non-polyadenylated mRNAs. This method generates a uniform 3' terminus by ligation of a 5'-phosphorylated oligonucleotide to the 3' end of the transcript that is recognized by a complementary primer during RT-PCR. This analysis showed that CIV virion proteins are encoded by genes in all three predetermined temporal classes: 23 immediate-early, 11 delayed-early and seven late virion gene transcripts were identified and assigned to ORFs. Early transcription of many virion protein genes supports the notion that virion proteins may also play essential roles in the initial stages of infection. In addition, some of the early gene products present in the virion may reflect the intracellular path that the virus follows during infection.