Zwitterion-Stabilized Silica Nanoparticles: Toward Nonstick Nano

Abstract

Using a short-chain zwitterionic organosiloxane, silica nanoparticles were stabilized against aggregation by high ionic strength and/or proteins. Turbidimetry and dynamic light scattering showed that "zwitterated" nanoparticles did not exhibit a significant increase in hydrodynamic radius. When challenged with 3 M NaCl or 50% fetal bovine serum, aggregation was inhibited for at least 24 h, longer with mild heat treatment, which produced nanoparticles with zero net surface charge. These findings suggest "zwitteration" of silica-capped nanoparticles provides excellent stability for in vivo circulation diagnostics and therapies.

Multifunctional Silica Nanoparticles for Covalent Immobilization of Highly Sensitive Proteins

“…[ 20 ] Installing thiol groups apparently increased the particle's affi nity for FLIP, as indicated by the slightly higher amount of adsorbed protein in the case of SiNP-3 as compared to SiNP-2 (Figure 2 B, magenta). To omit this unwanted binding, we coupled increasing amounts of methoxypolyethylene glycol maleimide (mPEG-mal) chains to the surface thiol groups using maleimide chemistry (Table S4, Supporting Information).…”

“…As an alternative for PEGylation, zwitterionfunctionalized SiNPs containing both positively and negatively charged functional groups have been synthesized and this modifi cation indeed effi ciently suppressed particle aggregation, [ 19 ] and non-specifi c adsorption of proteins. [ 20,21 ] However, these particles had an inert surface lacking reactive groups suitable for targeted bioconjugation.…”

Zwitterionic ceramics for biomedical applications

“…Schlenoff and co-workers reported the grafting of the highly water-soluble SB siloxane (SBS), to the surface of silica NPs (structure 2, Figure 2) [25,26]. In a first step they synthetized and isolated SBS by ring opening addition of propane sultone by an aminoalkylsiloxane.…”

Synthesis of a novel zwitterionic biodegradable poly (α,β-l-aspartic acid) derivative with some l-histidine side-residues and its resistance to non-specific protein adsorption

“…Recently, zwitterionic polymers are known to be effective in reducing protein adsorption [22][23][24][25]. The ultra-low fouling property is achieved by a uniformly mixture of balanced charges at the molecular scale on the modified surface.…”