scholarly journals Broad-Spectrum Bactericidal Activity of Ag2O-Doped Bioactive Glass

2002 ◽  
Vol 46 (6) ◽  
pp. 1940-1945 ◽  
Author(s):  
Maria Bellantone ◽  
Huw D. Williams ◽  
Larry L. Hench
Keyword(s):  
Bioactive Glass ◽  
Antibacterial Properties ◽  
Ionic Species ◽  
Bactericidal Effect ◽  
Graft Material ◽  
Bacterial Killing ◽  
Bactericidal Properties ◽  
New Material ◽  
45S5 Bioglass

ABSTRACT Bioactive glass has found extensive application as an orthopedic and dental graft material and most recently also as a tissue engineering scaffold. Here we report an initial investigation of the in vitro antibacterial properties of AgBG, a novel bioactive glass composition doped with Ag2O. The bacteriostatic and bactericidal properties of this new material and of two other bioactive glass compositions, 45S5 Bioglass and BG, have been studied by using Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus as test microorganisms. Concentrations of AgBG in the range of 0.05 to 0.20 mg of AgBG per ml of culture medium were found to inhibit the growth of these bacteria. Not only was AgBG bacteriostatic, but it also elicited a rapid bactericidal action. A complete bactericidal effect was elicited within the first hours of incubation at AgBG concentrations of 10 mg ml−1. 45S5 Bioglass and BG had no effect on bacterial growth or viability. The antibacterial action of AgBG is attributed exclusively to the leaching of Ag+ ions from the glass matrix. Analytical measurements rule out any contribution to AgBG-mediated bacterial killing by changes in pH or ionic strength or the dissolution of other ionic species from the biomaterials. Our observations of the dissolution profiles of Ag+ from AgBG in the presence and absence of bacteria are consistent with silver accumulation by the bacteria.

Fabrication of Zn-Sr–doped laser-spinning glass nanofibers with antibacterial properties

2016 ◽  
Vol 31 (6) ◽  
pp. 819-831 ◽  
Author(s):  
María Magdalena Echezarreta-López ◽  
Trinidad de Miguel ◽  
Félix Quintero ◽  
Juan Pou ◽  
Mariana Landín
Keyword(s):  
Antibacterial Activity ◽  
Bioactive Glass ◽  
Antibacterial Properties ◽  
Growth Index ◽  
Bactericidal Effect ◽  
Bioactive Glasses ◽  
Bioactive Materials ◽  
Nanofibrous Structure ◽  
The Media ◽  
45S5 Bioglass

The morphology and dimensions of bioactive materials are essential attributes to promote tissue culture. Bioactive materials with nanofibrous structure have excellent potential to be used as bone-defect fillers, since they mimic the collagen in the extracellular matrix. On the other hand, bioactive glasses with applications in regenerative medicine may present antibacterial properties, which depend on glass composition, concentration and the microorganisms tested. Likewise, their morphology may influence their antibacterial activity too. In the present work, the laser-spinning technique was used to produce bioactive glass nanofibers of two different compositions: 45S5 Bioglass® and ICIE16M, bioactive glass doped with zinc and strontium. Their antibacterial activity against Staphylococcus aureus was tested by culturing them in dynamic conditions. Bacterial growth index profiles during the first days of experiment can be explained by the variations in the pH values of the media. The bactericidal effect of the doped nanofibers at longer times is justified by the release of zinc and strontium ions. Cytotoxicity was analyzed by means of cell viability tests performed with BALB/3T3 cell line.

scholarly journals Synthesis and Characterization of Silver–Strontium (Ag-Sr)-Doped Mesoporous Bioactive Glass Nanoparticles

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Shaher Bano ◽  
Memoona Akhtar ◽  
Muhammad Yasir ◽  
Muhammad Salman Maqbool ◽  
Akbar Niaz ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Composite Coatings ◽  
Antibacterial Properties ◽  
Bone Diseases ◽  
Osteogenic Potential ◽  
Diffusion Method ◽  
Charge Composition ◽  
In Vitro Bioactivity ◽  
Mesoporous Bioactive Glass

Biomedical implants are the need of this era due to the increase in number of accidents and follow-up surgeries. Different types of bone diseases such as osteoarthritis, osteomalacia, bone cancer, etc., are increasing globally. Mesoporous bioactive glass nanoparticles (MBGNs) are used in biomedical devices due to their osteointegration and bioactive properties. In this study, silver (Ag)- and strontium (Sr)-doped mesoporous bioactive glass nanoparticles (Ag-Sr MBGNs) were prepared by a modified Stöber process. In this method, Ag+ and Sr2+ were co-substituted in pure MBGNs to harvest the antibacterial properties of Ag ions, as well as pro-osteogenic potential of Sr2 ions. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and in-vitro bioactivity was studied. Scanning electron microscopy (SEM), X-Ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) confirmed the doping of Sr and Ag in MBGNs. SEM and EDX analysis confirmed the spherical morphology and typical composition of MBGNs, respectively. The Ag-Sr MBGNs showed a strong antibacterial effect against Staphylococcus carnosus and Escherichia coli bacteria determined via turbidity and disc diffusion method. Moreover, the synthesized Ag-Sr MBGNs develop apatite-like crystals upon immersion in simulated body fluid (SBF), which suggested that the addition of Sr improved in vitro bioactivity. The Ag-Sr MBGNs synthesized in this study can be used for the preparation of scaffolds or as a filler material in the composite coatings for bone tissue engineering.

Biomorphic Silicon Carbide Ceramics Coated with Bioactive Glass for Medical Applications

2006 ◽  
Vol 514-516 ◽  
pp. 970-974 ◽  
Author(s):  
Jacinto P. Borrajo ◽  
Pio González ◽  
Julia Serra ◽  
Sara Liste ◽  
Stefano Chiussi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Bioactive Glass ◽  
The Body ◽  
Bioactive Materials ◽  
Bioactive Coatings ◽  
Metallic Substrates ◽  
New Material ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

There is a need to develop new tough bioactive materials capable to withstand high loads when implanted in the body and with improved fixation, which led to the production of bioactive coatings on metallic substrates. A new approach, which consists of biomorphic silicon carbide (SiC) coated with bioactive glass, was recently presented. This new material joins the high mechanical strength, lightness and porosity of biomorphic SiC, and the bioactive properties of PLD glass films. In this work, a multiple evaluation in terms of biocompatibility of this new material was carried out starting from the biomorphic SiC morphology and porosity, following with the bioactivity of the coatings in simulated body fluid, and ending with a deep biocompatibility study with MG-63 cells. Different ranges of porosity and pore size were offered by the biomorphic SiC depending on the starting wood. The PLD glassy coatings had a high bioactivity in vitro and both the biomorphic SiC coated and uncoated presented high levels of biocompatibility.

Experience with aniline dyes in the treatment of pyoderma

1934 ◽  
Vol 30 (5) ◽  
pp. 421-425
Author(s):  
I. N. Olesov ◽  
G. G. Kondratiev ◽  
E. G. Khusnutdinova
Keyword(s):  
Experimental Study ◽  
Methylene Blue ◽  
Methyl Violet ◽  
Bactericidal Effect ◽  
Methyl Green ◽  
Therapeutic Value ◽  
Bactericidal Properties ◽  
Clinical Verification ◽  
Aniline Dyes

The results of an experimental study of the bactericidal effect of aniline dyes (a.k.) obtained in our clinic (Kondratyev) set us the task to verify the therapeutic value of some a/c in the treatment of pyoderma. For clinical verification we chose a number of a.c, with different bactericidal properties in vitro: genzian violet (g.v.), methyl violet (m.v.) crystallviolet (c.v.) methylene blue (m.c.), methyl green (m.z.), vesuvine (c) and acidic fuchsin (f. K), which were used as aqueous and alcoholic solutions (96, 70, 50) of 1-5% concentration in the form of lubrications, injections and lotions, and in some cases in pure form (powder). A total of 190 patients were under our observation: inpatients - 57, outpatients - 133.

scholarly journals Development and Characterization of Bioactive Glass Containing Composite Coatings with Ion Releasing Function for Antibiotic-Free Antibacterial Surgical Sutures

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 423 ◽  
Author(s):  
Francesca Ciraldo ◽  
Kristin Schnepf ◽  
Wolfgang Goldmann ◽  
Aldo Boccaccini
Keyword(s):  
Bioactive Glass ◽  
Composite Coatings ◽  
Antibacterial Properties ◽  
Dip Coating ◽  
Carbonate Apatite ◽  
Polymeric Layer ◽  
Surgical Sutures ◽  
Dip Coating Technique ◽  
Doped Glass

Resorbable (Vicryl® Plus) sutures were coated with zinc-doped glass (Zn-BG) and silver-doped ordered mesoporous bioactive glass (Ag-MBG) particles by a dip coating technique. A multilayer approach was used to achieve robust coatings. The first coating was a polymeric layer (e.g., PCL or chitosan) and the second one was a composite made of BG particles in a polymer matrix. The coatings were characterized in terms of morphology by scanning electron microscopy (SEM), in vitro bioactivity, and antibacterial properties. Chitosan/Ag-MBG coatings showed the ability to form hydroxyl-carbonate-apatite on their surfaces after immersion in SBF. An antibacterial effect against Gram (+) and Gram (-) bacteria was confirmed, highlighting the potential application of the coated sutures for antibiotic-free approaches.

scholarly journals Mechanisms Mediating Bactericidal Properties and Conditions That Enhance the Potency of a Broad-Spectrum Oligo-Acyl-Lysyl

2010 ◽  
Vol 55 (2) ◽  
pp. 688-695 ◽  
Author(s):  
Hadar Sarig ◽  
Yair Goldfeder ◽  
Shahar Rotem ◽  
Amram Mor
Keyword(s):  
Membrane Damage ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bactericidal Effect ◽  
Cell Membrane Permeability ◽  
Permeability Barrier ◽  
Host Defense Peptides ◽  
Bactericidal Properties ◽  
Time Kill

ABSTRACTPrevious studies have established the potential of the oligo-acyl-lysyl (OAK) concept in generating simple chemical mimics of host defense peptides (HDPs) with improved antimicrobial properties. We investigated the antibacterial properties of such an OAK, C16(ω7)-KK-C12-Kamide, to obtain a better understanding of the complex mode(s) of action of cationic antibacterial peptides. The average MIC, determined against a multispecies panel of 50 strains, was 6 ± 5 μg/ml. However, although the OAK exerted an essentially dose-dependent bactericidal effect (time-kill curves typically exhibited 99% death within 2 h), marked differences in the killing rates occurred among inter- and intraspecies strains. Mechanistic comparison between equally sensitive and related strains revealed death of one strain to stem from the OAK's capacity to breach the cell membrane permeability barrier, whereas the death of the related strain resulted from the OAK's direct interference with DNA functionsin vivo, without detectable membrane damage. These findings therefore support the notion that the antibacterial mechanism of action of a single HDP can vary among inter- and intraspecies strains. In addition, we present data illustrating the differential effects of environmental conditions (pH, ionic strength and temperature), on the OAK's antibacterial properties, and ultimately demonstrate potency enhancement (by orders of magnitude) through selection of optimal incubation conditions. Such attributes might be useful in a variety of antibacterial applications.

scholarly journals THE BACTERICIDAL ACTION OF PROPYLENE GLYCOL VAPOR ON MICROORGANISMS SUSPENDED IN AIR. I

1942 ◽  
Vol 75 (6) ◽  
pp. 593-610 ◽  
Author(s):  
O. H. Robertson ◽  
Edward Bigg ◽  
Theodore T. Puck ◽  
Benjamin F. Miller ◽  
Keyword(s):  
Influenza Virus ◽  
Propylene Glycol ◽  
Marked Reduction ◽  
Bactericidal Effect ◽  
Bactericidal Action ◽  
Lethal Action ◽  
Droplet Form ◽  
Bactericidal Properties ◽  
Enclosed Space

It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed. With lesser concentrations of propylene glycol, rapid and marked reduction in the number of air-borne bacteria occurred, but complete sterilization of the air required a certain interval of time. Pronounced effects on both pneumococci and hemolytic streptococci were observed when concentrations as low as 1 gm. of glycol to fifty million cc. of air were employed. Numerous control tests showed that failure of the glycol-treated microorganisms to grow on the agar plates was due to actual death of the bacteria. The means by which propylene glycol vapor produces its effect on droplet-borne bacteria is discussed and data relating the bactericidal properties of propylene glycol in vitro to the lethal action of its vapor is presented. Atmospheres containing propylene glycol vapor are invisible, odorless, and non-irritating. This glycol is essentially non-toxic when given orally and intravenously. Tests on possible deleterious effects of breathing propylene glycol containing atmospheres over long periods of time are being carried out.

scholarly journals Pharmacokinetic-Pharmacodynamic Model for Gentamicin and Its Adaptive Resistance with Predictions of Dosing Schedules in Newborn Infants

2011 ◽  
Vol 56 (1) ◽  
pp. 179-188 ◽  
Author(s):  
Ami F. Mohamed ◽  
Elisabet I. Nielsen ◽  
Otto Cars ◽  
Lena E. Friberg
Keyword(s):  
Time Course ◽  
Newborn Infants ◽  
Bactericidal Effect ◽  
Preterm Neonates ◽  
Bacterial Killing ◽  
Content Type ◽  
Dosing Interval ◽  
Adaptive Resistance ◽  
Pkpd Model

ABSTRACTGentamicin is commonly used in the management of neonatal infections. Development of adaptive resistance is typical for aminoglycosides and reduces the antibacterial effect. There is, however, a lack of understanding of how this phenomenon influences the effect of different dosing schedules. The aim was to develop a pharmacokinetic-pharmacodynamic (PKPD) model that describes the time course of the bactericidal activity of gentamicin and its adaptive resistance and to investigate different dosing schedules in preterm and term newborn infants based on the developed model.In vitrotime-kill curve experiments were conducted on a strain ofEscherichia coli(MIC of 2 mg/liter). The gentamicin exposure was either constant (0.125 to 16 mg/liter) or dynamic (simulated concentration-time profiles in a kinetic system with peak concentrations of 2.0, 3.9, 7.8, and 16 mg/liter given as single doses or as repeated doses every 6, 12, or 24 h). Semimechanistic PKPD models were fitted to the bacterial counts in the NONMEM (nonlinear mixed effects modeling) program. A model with compartments for growing and resting bacteria, with a function allowing the maximal bacterial killing of gentamicin to reduce with exposure, characterized both the fast bactericidal effect and the adaptive resistance. Despite a lower peak concentration, preterm neonates were predicted to have a higher bacterial killing effect than term neonates for the same per-kg dose because of gentamicin's longer half-life. The model supported an extended dosing interval of gentamicin in preterm neonates, and for all neonates, dosing intervals of 36 to 48 h were as effective as a 24-h dosing interval for the same total dose.

scholarly journals Study on Bactericidal Effect of Biosynthesized Silver Nanoparticles in Combination with Gentamicin and Ampicillin on Pseudomonas aeruginosa

Nano Hybrids ◽  
2013 ◽  
Vol 3 ◽  
pp. 37-49 ◽  
Author(s):  
Shweta Rajawat ◽  
M.S. Qureshi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Direct Interaction ◽  
Antibacterial Activities ◽  
Bactericidal Effect ◽  
Bactericidal Properties ◽  
Vis Spectroscopy ◽  
Tea Extract

Silver nanoparticles are the most promising nanomaterial with antibacterial properties. Recent study of resistance to most potential antibiotics promotes research in the bactericidal activity of the silver nanoparticles. In this work, the effect of biosynthesized silver nanoparticles, in combination with gentamicin and ampicillin, on Pseudomonas Aeruginosa bacteria has been studied. Pseudomonas Aeruginosa is a common bacterium that can cause infections which are generalized as inflammation and sepsis. The results show that the bactericidal properties of the nanoparticles depends on the size of the as-synthesized silver nanoparticles as nanoparticles of diameter ~120 nm only have a direct interaction with the bacteria. It is observed that the antibacterial activities of antibiotics increase in the presence of AgNPs against test strains. Silver nanoparticles were synthesized elctrolytically using silver wire of 99% purity as anode and carbon rod wrapped with LDPE as cathode. 0.01 N Silver nitrate was used as an electrolyte. The process is termed as biosynthesis, because tea extract was used used as the capping agent which is also a very mild reducing agent. The polyphenols theaflavins and thearubigins, present in tea perform the role of stabilizing or capping agents due to their bulky and steric nature. A brown colored colloidal solution of silver nanoparticles is obtained. The as-synthesized silver nanoparticles were characterized using XRD, TEM and UV-Vis spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document