**5. Conclusions**

Methods described herein for the co-deposition of silver oxynitrate-silica in a one-pot synthesis yield a high purity silver oxynitrate within a three-dimensional silica framework. Spatially guided polymerization or deposition of silica, without the aid of alkyl silicates or surfactants, was achieved through the production of acidic by-product generated gradients from silver oxynitrate nucleation sites. Co-deposition of silica, from 0.1:1 to 0.5:1 molar equivalents SiO2:Ag, were shown to influence control over the crystalline size of silver oxynitrate while providing enhanced long term and thermal stability of silver oxynitrate within the silica framework. It was shown that the enhanced thermal stability of silver oxynitrate within the silica co-deposition framework did not hinder aqueous degradation profiles or antimicrobial and antibiofilm activity of silver oxynitrate. The methods described herein will confer increased stability and versatility of silver oxynitrate when incorporated into inherently reducing materials such as natural fibers or hydrogels and during thermal processing as required for materials such as silicones, melt adhesives, or thermoplastics. Providing an opportunity to expand the application of silver oxynitrate into novel functional materials to address the growing need for anti-infective technologies.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-3417/9/23/5236/s1.

**Author Contributions:** C.J.S.: Conceptualization, Methodology, Formal Analysis, Writing—Original Draft, Visualization, Project Administration, Supervision, Funding Acquisition. R.L.: Methodology, Validation, Investigation. C.G.: Methodology, Formal Analysis, Investigation, Data Curation, Writing—Review & Editing. M.H.: Methodology, Validation, Investigation, Formal Analysis. R.P.: Writing—Review & Editing, Supervision, Project Administration, Funding Acquisition.

**Funding:** This research was supported by the BioTalent Canada, Student Work Placement Program (SWPP) between Carlie Gooodall, student of the University of Guelph, and Exciton Technologies Inc.

**Acknowledgments:** The authors gratefully acknowledge the support of the Medical Imaging Laboratories and the Centre for Nanostructured Imaging at the University of Toronto in Toronto, Ontario.

**Conflicts of Interest:** Carla J. Spina, Michelle Hay, Roohee Ladhani, Carlie Goodall, and Rod Precht were employees of Exciton Technologies Inc. at the time the work was completed.
