Preparation, structural characterisation and antibacterial properties of Ga-doped sol–gel phosphate-based glass

A sol–gel preparation of Ga-doped phosphate-based glass with potential application in antimicrobial devices has been developed. Samples of composition (CaO)0.30(Na2O)0.20−x(Ga2O3)x(P2O5)0.50 where x = 0 and 0.03 were prepared, and the structure and properties of the gallium-doped sample compared with those of the sample containing no gallium. Analysis of the 31P MAS NMR data demonstrated that addition of gallium to the sol–gel reaction increases the connectivity of the phosphate network at the expense of hydroxyl groups. This premise is supported by the results of the elemental analysis, which showed that the gallium-free sample contains significantly more hydrogen and by FTIR spectroscopy, which revealed a higher concentration of –OH groups in that sample. Ga K-edge extended X-ray absorption fine structure and X-ray absorption near-edge structure data revealed that the gallium ions are coordinated by six oxygen atoms. In agreement with the X-ray absorption data, the high-energy XRD results also suggest that the Ga3+ ions are octahedrally coordinated with respect to oxygen. Antimicrobial studies demonstrated that the sample containing Ga3+ ions had significant activity against Staphylococcus aureus compared to the control.

[1]  Uwe Hoppe,et al.  Structural specifics of phosphate glasses probed by diffraction methods: a review , 2000 .

[2]  Y. Dimitriev,et al.  Infrared and Raman spectra of Ga2O3–P2O5 glasses , 2001 .

[3]  J. Rehr,et al.  High-order multiple-scattering calculations of x-ray-absorption fine structure. , 1992, Physical review letters.

[4]  J. Ding,et al.  MAS-NMR and FTIR analyses on the structure of CuO-containing sodium poly- and meta-phosphate glasses , 2003 .

[5]  J. Knowles.  Phosphate based glasses for biomedical applications , 2003 .

[6]  Michael T. Wilson,et al.  The effect of increasing copper content in phosphate-based glasses on biofilms of Streptococcus sanguis. , 2003, Biomaterials.

[7]  Richard K. Brow,et al.  Review: the structure of simple phosphate glasses , 2000 .

[8]  B. Britigan,et al.  Gallium Disrupts Iron Metabolism of Mycobacteria Residing within Human Macrophages , 2000, Infection and Immunity.

[9]  P. Armand,et al.  X-ray absorption and Raman characterizations of TeO2-Ga2O3 glasses , 2004 .

[10]  N. Cohen,et al.  Antimicrobial activity of gallium against virulent Rhodococcus equiin vitro and in vivo. , 2006, Journal of veterinary pharmacology and therapeutics.

[11]  J. Cole,et al.  An x-ray diffraction and 31P MAS NMR study of rare-earth phosphate glasses, (R2O3)x(P2O5)1-x, x = 0.175-0.263, R = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er , 2001 .

[12]  R. Kirkpatrick,et al.  Nuclear magnetic resonance investigation of the structures of phosphate and phosphate-containing glasses: a review. , 1995, Solid state nuclear magnetic resonance.

[13]  Tsunehiro Tanaka,et al.  Deconvolution Analysis of Ga K-Edge XANES for Quantification of Gallium Coordinations in Oxide Environments , 1998 .

[14]  Z. Gabelica,et al.  Structural characterization of glassy phases in the system Na2O-Ga2O3-P2O5 by MAS-NMR, EXAFS and vibrational spectroscopy. I. Cations coordination. , 2000, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[15]  J. Popp,et al.  Structural properties of silver nanoclusters–phosphate glass composites , 2007 .

[16]  David A. Fletcher,et al.  The United Kingdom Chemical Database Service , 1996, J. Chem. Inf. Comput. Sci..

[17]  A. K. Tyagi,et al.  Preparation, phase transition and thermal expansion studies on low-cristobalite type Al1−xGaxPO4 (x=0.0, 0.20, 0.50, 0.80 and 1.00) , 2003 .

[18]  Mark E. Smith,et al.  Multinuclear solid-state NMR of inorganic materials , 2002 .

[19]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[20]  C. Brinker.  Sol-gel science , 1990 .

[21]  R. Walton,et al.  An X-ray absorption fine structure study of amorphous precursors of a gallium silicate zeolite , 2001 .

[22]  J. Knowles,et al.  New sol–gel synthesis of a (CaO)0.3(Na2O)0.2(P2O5)0.5 bioresorbable glass and its structural characterisation , 2007 .

[23]  J. Knowles,et al.  The structure of phosphate glass biomaterials from neutron diffraction and 31P nuclear magnetic resonance data , 2007, Journal of physics. Condensed matter : an Institute of Physics journal.

[24]  Pradeep K. Singh,et al.  The transition metal gallium disrupts Pseudomonas aeruginosa iron metabolism and has antimicrobial and antibiofilm activity. , 2007, The Journal of clinical investigation.

[25]  Y. C. Li,et al.  [Effects of alpha-dimethylamino-cyclohexoxyl-dimethyl gallium on ultrastructure of erythrocytic stage of Plasmodium berghei and P yoelii]. , 1991, Zhongguo yao li xue bao = Acta pharmacologica Sinica.

[26]  L. Hench,et al.  Structural changes of silica xerogels during low temperature dehydration , 1986 .

[27]  Y. Nho,et al.  Introduction of phosphoric acid group to polypropylene film by radiation grafting and its blood compatibility , 2002 .

[28]  Roger Finch,et al.  Lack of development of new antimicrobial drugs: a potential serious threat to public health. , 2005, The Lancet. Infectious diseases.

[29]  P. Barboux,et al.  Sol-gel synthesis of phosphates , 1992 .

[30]  Quanzu Yang,et al.  Sol-gel hydroxyapatite coatings on stainless steel substrates. , 2002, Biomaterials.

[31]  Michael T. Wilson,et al.  Antimicrobial Gallium‐Doped Phosphate‐Based Glasses , 2008 .

[32]  V. Mudera,et al.  Soluble phosphate glasses: in vitro studies using human cells of hard and soft tissue origin. , 2004, Biomaterials.

[33]  Michael T. Wilson,et al.  Effect of increasing silver content in phosphate-based glasses on biofilms of Streptococcus sanguis. , 2003, Journal of biomedical materials research. Part A.

[34]  U. Pietsch,et al.  X-ray diffraction by a crystal in a permanent external electric field: electric-field-induced structural response in α-GaPO4 , 2006 .

[35]  J. Rehr,et al.  Theoretical approaches to x-ray absorption fine structure , 2000 .

[36]  L. Hench,et al.  The use of advanced diffraction methods in the study of the structure of a bioactive calcia: silica sol-gel glass. , 2005, Journal of materials science. Materials in medicine.

[37]  K. Hong,et al.  Properties and structure of RONa2OAl2O3P2O5 (R = Mg, Ca, Sr, Ba) glasses , 1995 .

[38]  J. Knowles,et al.  The structure and properties of silver-doped phosphate-based glasses , 2007 .

[39]  R. Gruehn,et al.  Contributions on the thermal behaviour of sulphates XVII.1Single crystal structure refinements of In2(SO4)3and Ga2(SO4)3 , 1995 .