Controlled delivery of antimicrobial gallium ions from phosphate-based glasses
Valappil, S. P., Ready, D., Abou Neel, E. A., Pickup, D. M., O'Dell, L. A., Chrzanowski, W., Pratten, J., Newport, R. J., Smith, Mark E., Wilson, M. and Knowles, J. C.. (2009) Controlled delivery of antimicrobial gallium ions from phosphate-based glasses. Acta Biomaterialia, Vol.5 (No.4). pp. 1198-1210. ISSN 1742-7061Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.actbio.2008.09.019
Gallium-doped phosphate-based glasses (PBGs) have been recently shown to have antibacterial activity. However, the delivery of gallium ions from these glasses can be improved by altering the calcium ion concentration to control the degradation rate of the glasses. In the present study, the effect of increasing calcium content in novel gallium (Ga2O3)-doped PBGs on the susceptibility of Pseudomonas aeruginosa is examined. The lack of new antibiotics in development makes gallium-doped PBG potentially a highly promising new therapeutic agent. The results show that an increase in calcium content (14, 15 and 16 mol.% CaO) cause a decrease in degradation rate (17.6, 13.5 and 7.3 mu g mm(-2) h(-1)), gallium ion release and antimicrobial activity against planktonic P. aeruginosa. The most potent glass composition (containing 14 mol.% CaO) was then evaluated for its ability to prevent the growth of biofilms of P. aeruginosa. Gallium release was found to reduce biofilm growth of P. aeruginosa with a maximum effect (0.86 log(10) CFU reduction compared to Ga2O3-free glasses) after 48 h. Analysis of the biofilms by confocal microscopy confirmed the anti-biofilm effect of these glasses as it showed both viable and non-viable bacteria on the glass surface. Results of the solubility and ion release studies show that this glass system is suitable for controlled delivery of Ga3+. Ga-71 NMR and Ga K-edge XANES measurements indicate that the gallium is octahedrally coordinated by oxygen atoms in all samples. The results presented here suggest that PBGs may be useful in controlled drug delivery applications, to deliver gallium ions in order to prevent infections due to P. aeruginosa biofilms. Crown Copyright (C) 2008 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved.
|Item Type:||Journal Article|
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Acta Biomaterialia|
|Publisher:||Elsevier Science Ltd.|
|Number of Pages:||13|
|Page Range:||pp. 1198-1210|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Engineering and Physical Sciences Research Council (EPSRC), University of Warwick|
|Grant number:||GR/T21080/01, EP/C000714/1 (EPSRC), EP/C000633/1 (EPSRC)|
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