Effects of selenium on toxicity and ultrastructural localization of silver in cultured macrophages

Aggressive cytotoxic treatment of cancer contributes to the growing number of life-threatening infections. Vascular catheters create predominant risks for staphylococcal, enterococcal and candida blood stream infections. Although the contaminating microorganisms may be few in number, the altered host immune response in the presence of such implants as well as disease-associated immunosuppression implies that even small bacterial counts have to be regarded as highly virulent species. Diagnosis of catheter-related infection (CRI) remains difficult before withdrawal of the suspected catheter. Positive culture of catheter surface, lumen and hub and positive peripheral blood probes (paired quantitative blood culture) are predictive for catheter related bacteremia (CRB). Diligent catheter care and effective antimicrobial catheters may reduce prolonged hospital stay, increased morbidity or mortality and serious economical consequences. The most promising approach features the incorporation of antimicrobial drugs into the polymer matrices that entrap but do not bind the drugs, allowing for extended release. For the efficacious prevention of colonization in the microenvironment of the implantable device the concentration of the antimicrobial substances must exceed usual antibiotic concentrations by a thousand-fold. This is the desired effect--high concentration near the device surface and very low systemic concentration. Incorporation of antimicrobials in the bulk material that constitutes a device can be effective as shown in several in vitro and in vivo studies. In the future, modification of both short-term and long-term catheters by biofilm-active antimicrobials creating slow delivery systems may provide an effective method to protect patients from nosocomial infection in oncology.

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“…6. Silver ion concentrations greater than 10 mg/ml are toxic to human cell cultures [63][64][65][66][67][68] .…”

Section: Silver-containing Biomedical Polymersmentioning

confidence: 99%

Novel Strategies to Prevent Catheter-Associated Infections in Oncology Patients

Schierholz¹,

Beuth²,

Rump³

et al. 2001

Journal of Chemotherapy

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“…19 Several studies have demonstrated that silver ions are selectively toxic for prokaryotic microorganisms, with little effect on eukaryotic cells. [20][21][22][23] Attempts have been made to prevent plaque accumulation on the surfaces of restorative materials by incorporating antibacterial agents such as chlorhexidine. [24][25][26] Although initially strong, this antibacterial effect did not last for long periods.…”

Section: Introductionmentioning

confidence: 99%

Characterization and inhibitory effect of antibacterial dental resin composites incorporating silver-supported materials

Yoshida

Tanagawa

Atsuta

1999

J. Biomed. Mater. Res.

147

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Resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. The purposes of this study were to investigate antibacterial light-activated dental resin composites incorporating each of two silver-supported antibacterial materials and evaluate their long-lasting inhibitory effect against Streptococcus mutans. Two types of silver-supported antibacterial materials, Novaron (N) and Amenitop (AM) were used. These antibacterial materials were incorporated into TEGDMA-UDMA-based light-activated resin composites, and the antibacterial activities and mechanical properties of these composites, and also the release of silver ions, were examined. Two silver-supported antibacterial materials inhibited the growth of the major oral pathogen S. mutans. The minimum inhibitory concentration in suspensions of N and AM against S. mutans was 40 microg/mL and 30 microg/mL, respectively. Composites incorporating 5 wt % (N-5) or more of Novaron and 7 wt % (AM-7) or more of Amenitop inhibited the growth of S. mutans after immersion in water for 6 months. There was no or extremely little release of silver ions from the N-5 and AM-7 composites after 1 day or after 6 months of immersion in water. No significant difference in either compressive or flexural strength was observed between the control and the N-5 composites after 1 day or after 6 months of storage in water. However, for the AM-5 composite, there was a significant difference in both strength parameters between the two immersion periods. These results indicate that a light-activated dental resin composite incorporating silver-supported antibacterial material such as Novaron may be useful clinically because of its long-lasting inhibitory effect against S. mutans and its favorable mechanical properties.

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“…Resin composites containing silver-ion-implanted fillers which release silver ions were found to have antibacterial effects on oral streptococci [Yamamoto et al, 1996]. Several studies have demonstrated that silver ions are selectively toxic for prokaryotic microorganisms, with little effect on eukaryotic cells [Marino et al, 1974;Spadaro and Becker, 1976;Webster et al, 1981;Rungby et al, 1987].…”

mentioning

confidence: 99%

Inhibitory Effect of Antibacterial Resin Composite against Streptococcus mutans

et al. 1999

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Dental resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. Three types of silver–supported antibacterial materials (Novaron, Amenitop and AIS) inhibited the growth of the major oral pathogen Streptococcus mutans. Minimum inhibitory amounts in suspensions of Novaron, Amenitop and AIS against S. mutans were 40, 30 and 400 μg/ml, respectively. These antibacterial materials were incorporated into TEGDMA–UDMA–based light–activated resin composite, and the antibacterial activities of these composites were examined. Composites incorporating 5 wt% (N–5) or more of Novaron and 7 wt% (AM–7) or more of Amenitop inhibited the growth of S. mutans, whereas composites incorporating up to 10 wt% of AIS did not. No significant difference in either compressive or flexural strength was observed between the control and N–5 composites after 1 day and 6 months of storage in water. However, for AM–5 composite, there was a significant difference in either strength parameter between the two immersion periods. There was no or extremely little release of silver ions from the N–5 and AM–5 composites after 1 day or 6 months of immersion in water. These results indicated that a light–activated resin composite incorporating silver–supported antibacterial material such as Novaron may be clinically useful due to its inhibitory effect against S. mutans and favorable mechanical properties.

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Effects of selenium on toxicity and ultrastructural localization of silver in cultured macrophages

Cited by 34 publications

References 27 publications

Novel Strategies to Prevent Catheter-Associated Infections in Oncology Patients

Novel Strategies to Prevent Catheter-Associated Infections in Oncology Patients

Characterization and inhibitory effect of antibacterial dental resin composites incorporating silver-supported materials

Inhibitory Effect of Antibacterial Resin Composite against Streptococcus mutans

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