Fabrication and Characterization of a Multifunctional Coating to Promote the Osteogenic Properties of Orthopedic Implants

Titanium-based alloys are used in orthopedic applications as fixation elements, hard tissue replacements in artificial bones, and dental implants. Despite their wide range of applications, metallic implant defects and failures arise due to inadequate mechanical bonding, postoperative clotting problems, aseptic loosening, and infections. To improve the surface bioactivity and reduce the corrosion rate of the Ti6Al4V alloy, multi-layered coatings (HAp, BG, Cs, and Hep) were applied via electrophoretic deposition (EPD). XRD images showed the presence of HAp within the coating. In vitro investigation: cell line NIH-3T3 fibroblasts were seeded on the non-coated and coated Ti6Al4V substrates, and their cellular behavior was evaluated. The results indicated that the HApBGCsHep coating could enhance the adhesion and proliferation of NIH 3T3 cells. In addition, the potentiodynamic polarization results are compatible with the in vitro outcome.

Evaluation of antioxidant and antimutagenic activities of aluminum chloride

Purpose:

Hemostatic agents are used to control hemorrhage and the gingival crevicular fluid for dental applications. In this study; the antimutagenic and antioxidant activities of aluminum chloride (AlCl3), a topical hemostatic agent used especially in the fields of dermatology and dentistry, were determined. To our knowledge, this is the first study that investigates these properties.

Materials and methods:

The antioxidant activity was determined by DPPH free radical scavenging and β-carotene-linoleic acid bleaching assays. The antimutagenic activity was evaluated with the Ames Salmonella/ microsome mutagenicity test using Salmonella typhimurium TA98 and TA100 strains.

Results:

The total antioxidant activity of AlCl3, determined by β-carotene bleaching assay was found to be 25.59 ± 2.55% and the DPPH scavenging activity of AlCl3 was determined as 17.49 ± 3.07%. AlCl3 showed not any mutagenicity at the tested concentrations by the AMES test used S. typhimurium TA98 and TA100. This drug demonstrated antimutagenic effects at the test concentrations and the strongest antimutagenic activity was observed on 1.25 mg·mL-1/plate concentration of AlCl3.

Conclusion:

AlCl3 showed potent antimutagenic and antioxidant activities and these properties are significant for dentistry and dermatology.

Characterisation of Streptomyces violascens OC125-8 lipase for oily wastewater treatment

In this study, the lipase-producing bacterium Streptomyces violascens (GenBank number MF621564) was identified, and the extracellular S. violascens OC125-8 lipase produced by this strain was characterised for use in wastewater treatment. The lipase was partially purified by ammonium sulphate precipitation at a final yield of 3.28-fold purification and a recovery of 56%. The S. violascens OC125-8 lipase exhibited optimum catalytic activity at 40 °C and pH 8.0; it was stable at 30-40 °C with more than 86% residual activity after 1 h; it was also stable over a relatively broad pH range of pH 7.0-11.0, retaining 83.3-100% activity. V _max and K _m values were calculated as 0.61 µmol/min/mg and 0.259 mM, respectively. Enzyme activity significantly increased in the presence of Fe²⁺ ion but was inhibited by Ca²⁺, Mn²⁺, Cu²⁺ and Mg²⁺. The addition of a serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), strongly inhibited enzyme activity while ethylenediaminetetraacetic acid (EDTA), a metal chelating agent, had no inhibitory effect. The enzyme was fairly stable in the presence of surfactants as well as sodium perborate. Examination of commercial detergent tolerance revealed that the lipase was strongly stable in Tursil (88%), Pril (97%) and Fairy (98.5%), while the lipase was activated in Omo (113.4%) and Ariel (128.3%). Moreover, the lipase showed highest activity towards olive oil (100%), sunflower oil (90%) and burned sunflower oil (55%), while corn oil (44%) and burned olive oil (15%) were less hydrolysed by the enzyme. These properties demonstrate that S. violascens OC125-8 lipase is an ideal choice for oily wastewater management.

Antimicrobial characteristics and biocompatibility of the surgical sutures coated with biosynthesized silver nanoparticles

Surgical sutures play important role during the wound healing of the surgical sites which are known to be sensitive to microbial infections. Silver nanoparticles (AgNPs) have been recently used as promising agents against multiple-drug resistant microorganisms. This study was designed to coat the sutures with silver nanoparticles obtained via a green synthesis approach. Microbial-mediated biological synthesis of AgNPs were carried out ecofriendly using Streptomyces sp. AU2 cell-free extract and deposited on silk sutures through an in situ process. Sutures coated with biosyntehsized AgNP (bio-AgNP coated sutures) were characterized using Scanning Electron Microscopy (SEM) and elemantal analysis were carried out using Energy Dispersive X-ray Spectroscopy (EDS). The silver amount released by the bio-AgNP coated sutures was calculated by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) throughout a degradation process. Antimicrobial potential of the bio-AgNP coated sutures was determined against common pathogenic microorganisms Candida albicans, Escherichia coli and Staphylococcus aureus. To determine the biocompatibility/cytotoxicty of the bio-AgNP coated sutures, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay was used through an indirect test method; that the elutions obtained by the extraction of the sutures at 1, 4, 8 and 10. days and were placed in contact with 3T3 fibroblast cell culture. To best of our knowledge, this is the first report about coating of the nonabsorbable silk sutures with silver nanoparticles biosynthesized using a microbial extract.

Functional denture soft liner with antimicrobial and antibiofilm properties

Background/purpose

Denture soft liners, especially used for elders who have poor disinfection habits, provide a favourable environment for accumulation and colonization of microorganisms. This in vitro study is aimed to investigate the effectiveness of natural carvacrol incorporation into soft lining material on the inhibition of oral pathogens.

Materials and methods

Antimicrobial susceptibility of carvacrol was primarily determined by disc diffusion method. Soft lining material was prepared as recommended by the manufacturer and 10 μL carvacrol was added aseptically to the soft liner discs. Inhibition zones for the control discs without carvacrol (C) and carvacrol-incorporated discs (CL) were determined by disc diffusion method. The biofilm inhibition percentages of carvacrol on soft liner was determined by MTT assay and also observed by Scanning Electron Microscopy (SEM).

Results

Carvacrol displayed great antimicrobial activity for yeast, Gram-negative and Gram-positive strains. The highest inhibition zone of carvacrol (41.33 ± 1.53 mm) was measured for Bacillus subtilis strain which is followed by Candida albicans and Streptococcus sanguis (34.00 ± 1.73 mm and 32.33 ± 0.58 mm, respectively). The inhibition zones were also similar for soft liner discs with carvacrol, with the highest inhibition zones against B. subtilis, Streptococcus mutans and C. albicans (43.67 ± 0.58 mm, 40.33 ± 0.58 mm and 38.33 ± 1.15 mm, respectively). Incorporation of carvacrol into the soft liner decreased (98.03 ± 0.2%) of the biofilm formation for C. albicans.

Conclusion

Carvacrol-incorporation obviously decreased the colonization and plaque formation of oral pathogens, especially C. albicans accumulation. Carvacrol may be useful as a promising agent for antibacterial and antifungal management for denture soft lining materials.

Antioxidant, mutagenic, and antimutagenic activities of Tragopogon longirostis var. longirostis, an edible wild plant in Turkey

Objectives:

The ethanolic extract of Tragopogon longirostis var. longirostis, a wild edible plant in Anatolia was isolated, and its antioxidant, mutagenic, and antimutagenic properties were investigated.

Materials and Methods:

The antioxidant activity (AA) was determined by the inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, total AA, and phenolic compounds. The mutagenic and antimutagenic activities were investigated by Ames Salmonella/microsome mutagenicity test.

Results:

The IC₅₀ value for DPPH radicals was 7.84 ± 0.603 mg/mL. The total AA increased with an increase in the concentration of the extracts (1, 5, 10, 20, and 30 mg/mL), containing linoleic acid emulsion. The total phenolic content was 284.71 ± 5.6 mg gallic acid equivalent/g extract. The results showed that the ethanolic extract can be considered safe, because it does not have any mutagenic effect at the tested concentrations. As a result, the ethanolic extract of the leaves exhibited antimutagenic effects at 2.5, 0.25, and 0.025 mg/plate concentrations.

Conclusions:

To our knowledge, this is the first study of the antioxidant, mutagenic, and antimutagenic activities of T. longirostis var. longirostis. These activities are an important topic in the food industry, as well as in the medical field.

Antimicrobial activity and chemical composition of endemic Centaurea cariensis subsp. niveo-tomentosa

The antimicrobial activity of the n-hexane, chloroform, ethyl acetate and ethyl alcohol extracts of the aerial parts of Centaurea cariensis subsp. niveo-tomentosa was evaluated against microorganisms, including multi-antibiotic resistant bacteria, using the paper disc diffusion method. The chemical composition of the chloroform extract of this plant was determined by gas chromatography and gas chromatography-mass spectrometry. The chloroform extract exhibited significant antibacterial activity for all bacteria tested, which are important pathogens. The major compounds of the chloroform extract were caryophyllene oxide (20.79%), spathulenol (14.73%), beta-eudesmol (9.27%), beta-caryophyllene (6.84%), n-cetylalcohol (6.27%), cubenol (5.23%) and cis-alpha-santalol (4.67%), respectively.

In vitro Study of Antibacterial Activity on Multi-Resistant Bacteria and Chemical Composition of the Chloroform Extract of Endemic Centaurea drabifolia subsp. cappadocica

The antimicrobial activity of the n-hexane, chloroform, ethyl acetate and ethanol extracts of the aerial parts of C. drabifolia S.M. subsp. cappadocica (DC.) Wagenitz (Asteraceae) was evaluated against microorganisms including multi-antibiotic resistant bacteria using the paper disc diffusion method. The chemical composition of the chloroform extract of this plant was determined by gas chromatography and gas chromatography-mass spectrometry. The chloroform extract exhibited significant antibacterial activity against all the bacteria tested, except Stenotrophomonas maltophilia MU63. The major compounds of the chloroform extract were spathulenol (14.1%), caryophyllene oxide (12.5%), octadecanol (10.2%), ethyl palmitate (7.7%), [Z,Z]-10,12-hexadecadienal (6.0%), 3-hydroxy p-anisaldehyde (5.9%) and pentacosane (5.8%).

In vitro study of antibacterial activity on multi-resistant bacteria and chemical composition of the chloroform extract of endemic Centaurea drabifolia subsp. cappadocica

The antimicrobial activity of the n-hexane, chloroform, ethyl acetate and ethanol extracts of the aerial parts of C. drabifolia S.M. subsp. cappadocica (DC.) Wagenitz (Asteraceae) was evaluated against microorganisms including multi-antibiotic resistant bacteria using the paper disc diffusion method. The chemical composition of the chloroform extract of this plant was determined by gas chromatography and gas chromatography-mass spectrometry. The chloroform extract exhibited significant antibacterial activity against all the bacteria tested, except Stenotrophomonas maltophilia MU63. The major compounds of the chloroform extract were spathulenol (14.1%), caryophyllene oxide (12.5%), octadecanol (10.2%), ethyl palmitate (7.7%), [Z,Z]-10,12-hexadecadienal (6.0%), 3-hydroxy p-anisaldehyde (5.9%) and pentacosane (5.8%).

Antimicrobial Activity and Chemical Composition of Senecio Sandrasicus on Antibiotic Resistant Staphylococci

The antimicrobial activity of hexane, chloroform, ethyl acetate and ethanol extracts of the aerial parts of S. sandrasicus P.H. Davis ( Asteraceae), endemic to Sandras mountain (Turkey), were determined. The antimicrobial activity of the extracts on microorganisms including multi-resistant staphylococci were evaluated using the disc diffusion method. The strains of multi-resistant staphylococci and the other standart bacteria were inhibited by some extracts. The volatile organic compouds of S. sandrasicus was determined by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The major compounds of hexane extract were aromadendrene oxide 2 (13.3%), spathulenol (12.5%) and β-caryophylene (11.8%), respectively.

Antimicrobial activity and chemical composition of Senecio sandrasicus on antibiotic resistant staphylococci

The antimicrobial activity of hexane, chloroform, ethyl acetate and ethanol extracts of the aerial parts of S. sandrasicus P.H.Davis (Asteraceae), endemic to Sandras mountain (Turkey), were determined. The antimicrobial activity of the extracts on microorganisms including multi-resistant staphylococci were evaluated using the disc diffusion method. The strains of multi-resistant staphylococci and the other standart bacteria were inhibited by some extracts. The volatile organic compouds of S. sandrasicus was determined by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The major compounds of hexane extract were aromadendrene oxide 2 (13.3%), spathulenol (12.5%) and beta-caryophylene (11.8%), respectively.

Antimicrobial activities of the essential oils of Origanum onites L., Origanum vulgare L. subspecies hirtum (Link) Ietswaart, Satureja thymbra L., and Thymus cilicicus Boiss. & Bal. growing wild in Turkey

In the present study, four separate samples of Origanum onites L., three separate samples of Satureja thymbra L., Origanum vulgare L. ssp. hirtum (Link) Ietswaart, and Thymus cilicicus Boiss. & Bal. were collected from various regions of Mugla, Turkey. The essential oils of these plants were obtained by the hydrodistillation method. Antimicrobial activities of the essential oils against microorganisms, including multiple antibiotic-resistant bacteria, were investigated using the disc diffusion method. Different antibiotic discs were used for comparison to the inhibition zones. All the essential oils used in this study were very effective against Gram-positive and Gram-negative bacteria, which included multiple resistant strains, except Pseudomonas aeruginosa ATCC 27853 and Pseudomonas fluorescens MU 87. The essential oils of the O. onites, O. vulgare ssp. hirtum, and S. thymbra were especially very effective against the resistant strains such as Stenotrophomonas maltophilia MU 64, S. maltophilia MU 99, and Chryseomonas luteola MU 65. The maximum antimicrobial activity was observed with the essential oils of O. onites. The antimicrobial activities of the essential oils varied depending on the species, subspecies, or variety. In fact, the essential oils of some plants belonging to the same species that were collected from different locations showed different levels of antimicrobial activities.