Nitric Oxide-Releasing Xerogels Synthesized from N-Diazeniumdiolate-Modified Silane Precursors

Abstract

Nitric oxide (NO)-releasing xerogel materials were synthesized using N-diazeniumdiolate-modified silane monomers that were subsequently co-condensed with an alkoxysilane. The NO-release characteristics were tuned by varying the aminosilane structure and concentration. The resulting materials exhibited maximum NO release totals and durations ranging from 0.45–3.2 µmol cm−2 and 20–90 h, respectively. The stability of the xerogel networks was optimized by varying the alkoxysilane backbone identity, water to silane ratio, base catalyst concentration, reaction time, and drying conditions. The response of glucose biosensors prepared using the NO-releasing xerogel (15 mol% N-diazeniumdiolate-modified N-2-(aminoethyl)-aminopropyltrimethoxysilane) as an outer sensor membrane was linear (R2 = .979) up to 24 mM glucose. The sensitivity (3.4 nA mM−1) of the device to glucose was maintained for 7 d in phosphate buffered saline. The facile sol-gel synthetic route, along with the NO release and glucose biosensor characteristics, demonstrates the versatility of this method for biosensor membrane applications.

Dual action antimicrobial surfaces via combined nitric oxide and silver release

“…Nitric oxide release from the N ‐diazeniumdiolate NO donor‐modified xerogels was measured using a chemiluminescent NO analyzer (Sievers 280i, Boulder, CO) as described previously . Xerogels were placed in 30 mL deoxygenated phosphate‐buffered saline (PBS; 37 o C; pH 7.4).…”

Nanomaterial Nitric Oxide Delivery in Traumatic Orthopedic Regenerative Medicine

“…Given that external fixators are often used in the setting of contaminated open fractures, these NO-releasing xerogel polymer composites could potentially be of significant clinical value. The rate of NO release from NONOate-modified xerogels varies based on the type of aminosilane precursor molecule, with NO release half-lives ranging from 1.7 to 5.7 h (Storm and Schoenfisch, 2013 ). However, the most important factor influencing NO release rates has been shown to be the hydrophobicity of the xerogel matrix, rather than intramolecular NONOate stabilization by 1° amines (Storm and Schoenfisch, 2013 ).…”

“…The rate of NO release from NONOate-modified xerogels varies based on the type of aminosilane precursor molecule, with NO release half-lives ranging from 1.7 to 5.7 h (Storm and Schoenfisch, 2013 ). However, the most important factor influencing NO release rates has been shown to be the hydrophobicity of the xerogel matrix, rather than intramolecular NONOate stabilization by 1° amines (Storm and Schoenfisch, 2013 ). Riccio et al used sol-gel chemistry to form RSNO-modified xerogels as NO-releasing coatings, and sought to explore the ability of the coating to resist bacterial and platelet adhesion (Riccio et al, 2009 ).…”

“…All NO donor nanomaterials described above serve this purpose, and thus all serve to prolong the action of NO. Through the incorporation of NO into donor nanomaterials, the release half-life of NO has now been increased to be on the order of hours instead of seconds (Stasko and Schoenfisch, 2006 ; Shin et al, 2007 ; Hetrick et al, 2008 ; Storm and Schoenfisch, 2013 ; Duong et al, 2014 ; Lin et al, 2018 ; Pant et al, 2019 ). This prolonged duration of action provided by nanomaterial delivery of NO is biologically beneficial, as the effect of NO on osteoblast and osteoclast function is dependent on prolonged exposure of these cells to low doses of NO (van't Hof and Ralston, 2001 ; Kalyanaraman et al, 2018 ), and the bactericidal effect of NO is also dependent on prolonged exposure of bacteria to NO (Kostakioti et al, 2013 ; Duong et al, 2014 ).…”

Modulation of the lifespan of C. elegans by the controlled release of nitric oxide

“…nitrosothiols and NONOates, are conditional and spontaneous NO donors. [22][23][24][25][26][27][28] Their NO release is heavily inuenced by local environment parameters such as thiols and pH, and it is not on/off-switchable when necessary. 29,30 Ideally, the NO donor is photo-triggered and photo-calibrated.…”