3D Propolis-Sodium Alginate Scaffolds: Influence on Structural Parameters, Release Mechanisms, Cell Cytotoxicity and Antibacterial Activity

FEN-C-YLP-130319-0065 BAPKO Project. UID/CTM/50025/2019In this study, the main aim was to fabricate propolis (Ps)-containing wound dressing patches using 3D printing technology. Different combinations and structures of propolis (Ps)-incorporated sodium alginate (SA) scaffolds were developed. The morphological studies showed that the porosity of developed scaffolds was optimized when 20% (v/v) of Ps was added to the solution. The pore sizes decreased by increasing Ps concentration up to a certain level due to its adhesive properties. The mechanical, swelling-degradation (weight loss) behaviors, and Ps release kinetics were highlighted for the scaffold stability. An antimicrobial assay was employed to test and screen antimicrobial behavior of Ps against Escherichia coli and Staphylococcus aureus strains. The results show that the Ps-added scaffolds have an excellent antibacterial activity because of Ps compounds. An in vitro cytotoxicity test was also applied on the scaffold by using the extract method on the human dermal fibroblasts (HFFF2) cell line. The 3D-printed SA-Ps scaffolds are very useful structures for wound dressing applications.publishersversionpublishe

Group B Streptococci Induce Interleukin 8 Production in Human Cervical Epithelial Cell Cultures: The Role of Capsule Polysaccharide

Objective: Group B streptococci (GBS) are the major cause of pneumonia, sepsis, and meningitis in neonates and adults. Epithelial invasion and early cytokine response of female genital tract considered to be important in the pathogenesis of GBS infection. In this study, we studied the IL-8 induction in cervical epithelial cells in response to stimulus with encapsulated (COH1) and unencapsulated (COH1-13) strains of group B streptococci. Methods: Human cervical epithelial cell (HeLa) cultures were stimulated with different concentrations (10(6) CFU/ml and 10(8) CFU/ml) of two GBS strains. E.coli LPS was used as positive control and at specified time points (4, 8 and 24 hour) cell culture supernatant samples were collected. IL-8 level in samples was quantified by using ELISA assay. Results: Both GBS strains caused an equal IL-8 response in HeLa cells in a time-dependent manner. In addition, cytokine levels triggered by different bacterial concentrations were similar and comparable with LPS. Conclusion: Our study showed that GBS induce proinflammatory IL-8 levels in cervix epithelial cells. This induction seems to be independent from capsule polysaccharides and suggesting that other bacterial components are involved in IL-8 stimulation

Amphiphilic water soluble cationic ring opening metathesis copolymer as an antibacterial agent

Bacterial infection is a global problem, especially resistance acquired by bacteria against to antibiotics; there is urgent need for the development of antibiotics. Here, we proposed dendron-grafted polymers via ring opening metathesis polymerization (ROMP) featuring different with tailored hydrophobicity/hydrophilicity and cationic charges. Dendritic oxanorbornene derivatives were synthesized having two and six carbon linkers and their corresponding random and block copolymers were prepared having pendant pyridinium salt moieties via ROMP. In total, 12 different water-soluble dendronized cationic polymers featuring hexyl pyridinium moieties were prepared and investigated. Six carbon linker possessing triple charge density and hexyl pyridinium functionality each repeating unit copolymers exhibited high antibacterial activity against Gram-positive bacteria (S. aureus). However, all the polymers were inactive against Gram-negative bacteria (E. coli). Most of the copolymers are non-hemolytic (>HC (50) = 1,000 mu g/ml). It was also observed that, there is no significant effect between block copolymers and random copolymers keeping hydrophobicity and cationic charge density constant. Zeta potential was measured to investigate the mechanism in solution via the interaction of polymers with S. aureus, while scanning electron microscope (SEM) measurements image confirms damage of the bacterial cell wall after implementation of biocidal polymer

Enhanced Light-Driven Antimicrobial Activity of Cationic Poly(oxanorbornene)s by Phthalocyanine Incorporation into Polymer as Pendants

Amphiphilic poly(oxanorbornene)s are promising synthetic polymers that mimic the structural properties and antimicrobial functions of naturally occurring antimicrobial peptides. Here, poly(oxanorbornene)s bearing pendant zinc(II) phthalocyanine and triphenyl(ethyl) phosphonium functionalities are synthesized by ring-opening metathesis polymerization (ROMP). Fluorescence, singlet oxygen and triplet quantum yields of polymers are measured in dimethyl sulfoxide and aqueous medium. The singlet oxygen quantum yields of copolymers with the highest triphenyl and triethyl phosphonium content are found to be 0.29 and 0.41, respectively. Then, antimicrobial activities of polymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are investigated under both dark and light conditions. Synergistic effect of zinc(II) phthalocyanine and phosphonium-containing poly(oxanorbornene) is observed that the conjugate possessing the most triphenyl phosphonium side chains has the highest activity under light against both gram-positive and gram-negative bacterial strains after 80 min irradiation, reducing the survival of E. coli or S. aureus by 99.9999%. Hemolytic concentrations of the copolymers are found between 8 and 512 mu g mL(-1). Scanning electron microscopy (SEM) proves that the bacteria membrane deforms after contacting with the biocidal polymer

A prospective study: Inflammation, infection and comorbidity in patients on long-term dialysis

SUMMARY: Background: The goal of this study was to identify inflammatory and infectious markers and their roles in mortality. Methods: We enrolled 111 patients on haemodialysis (HD) and collected data at three time points (baseline, 33 and 76 months). Results: Rates of Chlamydophila pneumoniae IgG, CRP ≥3mg/l, ESR >50mm/hour and fibrinogen >4g/l were, respectively, 63.1%, 60.4%, 48.6% and 42.3%. Mortality was 21.6% and 43.2% at 33 and 76 months where 58.3% of all deaths were cardiocerebrovascular (CCV) related. Non-survivors were older than survivors. Univariate analysis showed diabetes mellitus (DM) and cerebrovascular accident (CVA) as important for the 33-month all-cause mortality, and CRPlog, fibrinogen, ESR >50mm/hour, cardiovascular disease (CVD) and DM for the 76-month all-cause mortality. CVA was meaningful for the 33-month CCV mortality, and CVD, DM and ESR >50mm/hour for the 76-month CCV mortality. Kaplan-Meier revealed poorer survival for patients with ESR >50mm/hour at 76 months. Cox regression showed CVD, CVA and age as mortality predictors. Conclusion: Age, CVD and CVA are predictors for mortality in patients on HD patients, but the presence of C. pneumoniae IgG and inflammation are not. © 2013 European Dialysis and Transplant Nurses Association/European Renal Care Association

Synthesis of 1,4-diazabicyclo[2.2.2]octane and pyridinium based cationic polymers via ROMP technique and examination of their antibacterial activity and cytotoxicity

This paper focuses on the synthesis of cationic antibacterial polymers that could be a potential source for new-generation antibiotics with well-defined architecture derived from the Ring Opening Metathesis Polymerization (ROMP) technique. Mono- and double-charge bearing quaternary groups have been used to synthesize cationic homopolymers (MWs: 3000 and 10,000 g/mole) and their copolymers (MWs: 5000 g/mole). Hemolytic concentration (HC50, >= 1000 mu g/mL) and MTS assay results showed that the polymers are non-toxic. It has been observed that the double-charge bearing polymers have the highest antimicrobial activity (S. aureus= 8 mu g/mL) and a high selectivity against S. aureus (>250). Percent killing efficiencies were tested on a glass surface where moderate killing efficiency was observed in the range of 40-80% in 5 min. Cationic charge density and zeta potential studies were used to investigate the mechanisms of antimicrobial efficiency of the polymers in a solution during the action against S. aureus to understand structure-activity relationships. Scanning electron microscopy (SEM) was also conducted for the bacterial morphology assay

Extremely Low-Frequency Electromagnetic Fields Affect the Immune Response of Monocyte-Derived Macrophages to Pathogens

This study aimed to determine the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on the physiological response of phagocytes to an infectious agent. THP-1 cells (human monocytic leukemia cell line) were cultured and 50 Hz, 1 mT EMF was applied for 4-6 h to cells induced with Staphylococcus aureus or interferon gamma/lipopolysaccharide (IF gamma/LPS). Alterations in nitric oxide (NO), inducible nitric oxide synthase (iNOS) levels, heat shock protein 70 levels (hsp70), cGMP levels, caspase-9 activation, and the growth rate of S. aureus were determined. The growth curve of exposed bacteria was lower than the control. Field application increased NO levels. The increase was more prominent for S. aureus-induced cells and appeared earlier than the increase in cells without field application. However, a slight decrease was observed in iNOS levels. Increased cGMP levels in response to field application were closely correlated with increased NO levels. ELF-EMF alone caused increased hsp70 levels in a time-dependent manner. When cells were induced with S. aureus or IF gamma/LPS, field application produced higher levels of hsp70. ELF-EMF suppressed caspase-9 activation by a small extent. These data confirm that ELF-EMF affects bacterial growth and the response of the immune system to bacterial challenges, suggesting that ELF-EMF could be exploited for beneficial uses. Bioelectromagnetics 31:603-612, 2010. (C) 2010 Wiley-Liss, Inc

Effect of extremely low frequency electromagnetic fields on bacterial membrane

Purpose: The effect of extremely low frequency electromagnetic fields (ELF-EMF) on bacteria has attracted attention due to its potential for beneficial uses. This research aimed to determine the effect of ELF-EMF on bacterial membrane namely the membrane potential, surface potential, hydrophobicity, respiratory activity and growth.Materials and methods: Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were subjected to ELF-EMF, 50Hz, 1mT for 2h. Membrane potential was determined by fluorescence spectroscopy with or without EDTA (Ethylenediaminetetraacetic acid) with DisC3(5) (3,3-dipropylthiacarbocyanine iodide), zeta potential measurements were performed by electrophoretic mobility, hydrophobicity of the membrane was measured with MATH (Microbial Adhesion to Hydrocarbons) test, respiratory activity was determined with CTC (5-Cyano-2,3-ditolyl tetrazolium chloride), colony forming unit (CFU) and DAPI (4,6-diamidino-2-phenylindole, dihydrochloride) was used for growth determinations.Results: ELF-EMF caused changes in physicochemical properties of both Gram-positive and Gram-negative bacteria. Hyperpolarization was seen in S. aureus and EDTA-treated E. coli. Surface potential showed a positive shift in S. aureus contrariwise to the negative shift seen in EDTA-untreated E. coli. Respiratory activity increased in both bacteria. A slight decrease in growth was observed.Conclusion: These results show that ELF-EMF affects the crucial physicochemical processes in both Gram-positive and Gram-negative bacteria which need further research

Evaluation of 2015-2016 MOTAKK HBV DNA and HCV RNA External Quality Assessment National Program Results

MOTAKK, as a national external quality control program has been launched to evaluate the molecular detection of viral infections including HBV DNA and HCV RNA in molecular microbiology diagnostic laboratories in Turkey. This program is prepared in compliance with ISO 17043:2010 (Conformity assessment general requirements for proficiency testing) standards, and aims to take the place of external quality control programs from abroad, contributing to standardization and accuracy of molecular diagnostic tests in our country. The aim of this study was to evaluate 2015 and 2016 results of the MOTAKK External Quality Control Program for HBV DNA and HCV RNA viral load. The calls were announced on the web page of MOTAKK (www.motakk.org). The quality control samples were sent to participating laboratories in 2015 and 2016. Main stocks were prepared from patients with chronic hepatitis B and C who had viral load detection with reference methods according to WHO reference materials for viral load studies to improve quality control sera. From these main stocks, samples with different viral loads were prepared from dilutions of plasma with HBV, HCV, HAV, HIV, Parvovirus B19 and CMV negative serologic markers. Quality control samples were sent to the participating laboratories along with the negative samples in the cold chain. The laboratories accomplished the related tests within 2-3 weeks and entered their results on the MOTAKK web page. These results were analysed according to ISO 13528 (Statistical methods for use in proficiency testing by interlaboratory comparison) and scoring reports were created by a software developed by MOTAKK and sent to participating labs. Each laboratory evaluated their own results in comparison with the other laboratory results, reassessed the tests via observing the distance from the mean result and the reference values. The number of laboratories participating in the HBV DNA and HCV RNA external quality control program was 70-73 in 2015-2016. Participants were able to comply with the program tools, registering, entering results and receiving the results reports problem. In HBV panel, 72.6-89.1% and 84.7-90.3% of the participant laboratories were in 1 standard deviation (SD) in 2015-2016, respectively. In HCV panel, 70.8-89.1% and 84.7-90.3% of the participant laboratories were in 1 SD in 2015-2016, respectively. A national external quality control program for HBV DNA and HCV RNA in Turkey has been prepared for the first time with this project and implemented successfully. All the data provided in the MOTAKK external quality control program final report, compensate all the data provided by the quality control program final reports from abroad; additionally, the report allows comparison of used technologies and commercial products