Functionalized Mesoporous Silica via an Aminosilane Surfactant Ion Exchange Reaction: Controlled Scaffold Design and Nitric Oxide Release

Abstract

Nitric oxide-releasing mesoporous silica nanoparticles (MSNs) were prepared using an aminosilane-template surfactant ion exchange reaction. Initially, bare silica particles were synthesized under basic conditions in the presence of cetyltrimethylammonium bromide (CTAB). These particles were functionalized with nitric oxide (NO) donor precursors (i.e., secondary amines) via the addition of aminosilane directly to the particle sol and a commensurate ion exchange reaction between the cationic aminosilanes and CTAB. N-Diazeniumdiolate NO donors were formed at the secondary amines to yield NO-releasing MSNs. Tuning of the ion exchange-based MSN modification approach allowed for the preparation of monodisperse particles ranging from 30 to 1100 nm. Regardless of size, the MSNs stored appreciable levels of NO (0.4–1.5 μmol mg–1) with tunable NO release durations (1–33 h) dependent on the aminosilane modification. Independent control of NO release properties and particle size was achieved, demonstrating the flexibility of this novel MSN synthesis over conventional co-condensation and surface grafting strategies.

The Effects of Nonporous Silica Nanoparticles on Cultured Human Keratocytes

“…SiNPs can be successfully combined with various nitric oxide donors to become a controlled delivery platform for nitric oxide to target tissue. 42,43 As previously reported, nitric oxide releasing silica nanoparticles can be useful in controlling intraocular pressure. 44,45 Corneal wound healing modulation is another possibility for nitric oxide releasing SiNPs.…”

Mesoporous Silica and Organosilica Nanoparticles: Physical Chemistry, Biosafety, Delivery Strategies, and Biomedical Applications

“…Consequently, various studies have shown the potential of releasing NO via organosilica‐based materials for antibacterial applications and various therapies based on the delivery of gaseous molecules into cells . Schoenfisch and co‐workers pioneered several NO‐releasing silica systems for various applications with payloads ranging from 0.3 to 2.4 µmol NO per mg of NPs with NO release half‐lives from 10 min to 23 d . Historically, the first examples NO‐releasing systems were nonporous and showed therapeutic properties such as inhibiting the growth of ovarian cancer cells …”

Mesoporous Silica Particles for Dermal Drug Delivery: A Review

“…-alkoxysilanes where MCM-41 and SBA-15 acts as a structure-directing agent present on the pore walls so that organic residues are obtained. The primary advantage of this method is that less blockade of pores are seen due to the presence of organic functionalities which discharge into the pores of the silica particles and organic particles are uniformly distributed over the pores of silica particles when compared with the grafting process [50,51]. The drawbacks of this method include improper functionalization can occur, and the proportion of concentration of organic groups present on the pore walls varies leading to lower concentrations at the extreme groups compared with the initial groups.…”