Limits...
Antibacterial and Antifungal Activity of ZnO Containing Glasses.

Esteban-Tejeda L, Prado C, Cabal B, Sanz J, Torrecillas R, Moya JS - PLoS ONE (2015)

Bottom Line: A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15-40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed.These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible.These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomaterials and Bioinspired Materials, Materials Science Institute of Madrid, (ICMM), Spanish National Research Council (CSIC), Cantoblanco, Madrid, 28049, Spain.

ABSTRACT
A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15-40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed. These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible. The cytotoxicity was evaluated by the Neutral Red Uptake using NIH-3T3 (mouse embryonic fibroblast cells) and the cell viability was >80%. These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles.

No MeSH data available.


Related in: MedlinePlus

A) 23Na, 11B, 27Al, 29Si NMR spectra of the glass powder ZnO25. B) Chemical shift values as a function of zinc content in ZnO15, ZnO25, ZnO35 and ZnO40.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4521915&req=5

pone.0132709.g004: A) 23Na, 11B, 27Al, 29Si NMR spectra of the glass powder ZnO25. B) Chemical shift values as a function of zinc content in ZnO15, ZnO25, ZnO35 and ZnO40.

Mentions: The local structure of glasses was assessed by NMR spectroscopy. For that the local environment of B, Na, Al and Si atoms was analyzed with the MAS-NMER technique. The 11B, 23Na, 27Al and 29Si, MAS-NMR spectra of the glass powder ZnO25 is displayed in Fig 4A as example. Chemical shift values as a function of Zn content in ZnO15, ZnO25, ZnO35 and ZnO40 are compiled in Fig 4B. This figure reveals that the addition of ZnO does not affect Na, Al and B NMR spectra, indicating that structural positions occupied by B, Al atoms (BO4, AlO4) do not appreciably change along the series but it does the Si (SiO4) one. The increment in the ZnO content causes the maximum shifting from the Si NMR envelope -100 ppm (ZnO15) to -85ppm (ZnO35) showing a linear tendency. Based on the chemical shift values reported in literature [46], the SiO4 tetrahedral in the ZnO15 and ZnO25 glasses is involved basically in Q3 environments but it changes to a Q2 one in the ZnO35 glass. Conversely, the ZnO40 glass breaks this tendency showing the spectral maximum at -90 ppm that corresponds again to Q2 environments. These structural changes affect the Tg, Th as well as the thermal expansion coefficients of the glasses as can be observed in Table 2. In the case of ZnO15 to ZnO35 there is a monotonically decrease of the fraction of silica (Table 1) and as a consequence, the Tg and Th decrease and the thermal expansion coefficients increase (Table 2). Conversely, the ZnO40 glass displays a completely different trend, the Tg and Th increase and the thermal expansion coefficient decreases (Table 2) showing a Q2 structure as the ZnO35 glass. This particular behavior can be rationalized considering a change in the structural role of ZnO from network modifier to network former along the series. In the case of ZnO15, ZnO25 and ZnO35 glasses it is clear that the ZnO acts as a modifier and produces the depolymerization of the SiO2. However, in the case of the ZnO40, where silicon Q2 associations prevail, the ZnO must act as network former diluting less polymerized silicon associations in resulting networks. This fact can also explain the results of the chemical durability study (Table 2).


Antibacterial and Antifungal Activity of ZnO Containing Glasses.

Esteban-Tejeda L, Prado C, Cabal B, Sanz J, Torrecillas R, Moya JS - PLoS ONE (2015)

A) 23Na, 11B, 27Al, 29Si NMR spectra of the glass powder ZnO25. B) Chemical shift values as a function of zinc content in ZnO15, ZnO25, ZnO35 and ZnO40.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4521915&req=5

pone.0132709.g004: A) 23Na, 11B, 27Al, 29Si NMR spectra of the glass powder ZnO25. B) Chemical shift values as a function of zinc content in ZnO15, ZnO25, ZnO35 and ZnO40.
Mentions: The local structure of glasses was assessed by NMR spectroscopy. For that the local environment of B, Na, Al and Si atoms was analyzed with the MAS-NMER technique. The 11B, 23Na, 27Al and 29Si, MAS-NMR spectra of the glass powder ZnO25 is displayed in Fig 4A as example. Chemical shift values as a function of Zn content in ZnO15, ZnO25, ZnO35 and ZnO40 are compiled in Fig 4B. This figure reveals that the addition of ZnO does not affect Na, Al and B NMR spectra, indicating that structural positions occupied by B, Al atoms (BO4, AlO4) do not appreciably change along the series but it does the Si (SiO4) one. The increment in the ZnO content causes the maximum shifting from the Si NMR envelope -100 ppm (ZnO15) to -85ppm (ZnO35) showing a linear tendency. Based on the chemical shift values reported in literature [46], the SiO4 tetrahedral in the ZnO15 and ZnO25 glasses is involved basically in Q3 environments but it changes to a Q2 one in the ZnO35 glass. Conversely, the ZnO40 glass breaks this tendency showing the spectral maximum at -90 ppm that corresponds again to Q2 environments. These structural changes affect the Tg, Th as well as the thermal expansion coefficients of the glasses as can be observed in Table 2. In the case of ZnO15 to ZnO35 there is a monotonically decrease of the fraction of silica (Table 1) and as a consequence, the Tg and Th decrease and the thermal expansion coefficients increase (Table 2). Conversely, the ZnO40 glass displays a completely different trend, the Tg and Th increase and the thermal expansion coefficient decreases (Table 2) showing a Q2 structure as the ZnO35 glass. This particular behavior can be rationalized considering a change in the structural role of ZnO from network modifier to network former along the series. In the case of ZnO15, ZnO25 and ZnO35 glasses it is clear that the ZnO acts as a modifier and produces the depolymerization of the SiO2. However, in the case of the ZnO40, where silicon Q2 associations prevail, the ZnO must act as network former diluting less polymerized silicon associations in resulting networks. This fact can also explain the results of the chemical durability study (Table 2).

Bottom Line: A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15-40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed.These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible.These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomaterials and Bioinspired Materials, Materials Science Institute of Madrid, (ICMM), Spanish National Research Council (CSIC), Cantoblanco, Madrid, 28049, Spain.

ABSTRACT
A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15-40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed. These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible. The cytotoxicity was evaluated by the Neutral Red Uptake using NIH-3T3 (mouse embryonic fibroblast cells) and the cell viability was >80%. These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles.

No MeSH data available.


Related in: MedlinePlus