Amino-functionalized silica nanoparticle

Alternating different layers of amino-functionalized silica nanoparticles (295 nm diameter) and epoxy-functionalized smaller silica nanoparticles (20 nm diameter), hybrid organic/inorganic surfaces have been constructed using the concept of covalent layer-by-layer assembly (covalent LbL) for the elaboration of films from polymers or den-drimers. ... 

Novel one-pot sol-gel preparation of amino-functionalized silica nanoparticles. Chem. Lett, 37 (11),... 

The most commonly used method to exploit silica for gene delivery is by functionalizing the surface of the NPs with aminosi-lanes (either N-(2-aminoethyl)-3-aminopropyltrimethoxysilane or N-(6-aminohexyl)- 3-aminopropyltrimethoxysilane). The group of Lehr showed that commercially available silica NPs functionalized with N-(6-aminohexyl)- 3-aminopropyltrimethoxysilane were able to transfect efficiently Cos-1 cells with very low toxicity. Other cationic silica nanoparticles with surfaces modified by amino-hexyl-aminopropyltri- methoxysilane (AHAPS) were also reported recently to be successful transfection reagents. He et al used a similar approach but they directly synthesised positively charged amino-modified silica NPs. They showed that these NPs were able to protect pDNA from DNasel degradation in vitro in Cos-7 cells, thus evidencing a simple and efficient protection method. Zhu et also showed the successful delivery of antisense ODN with poly(L-lysine) functionalized silica nanoparticles in HNEI and HeLa cells. 

FIGURE 14.1 Diagram of the general procedure for embedding nanoparticles in silica colloids in the first step, PVP is adsorbed on the colloidal particles (1). After transfer in an alcohol, for example, ethanol or butanol, the particles are adsorbed on amino-functionalized silica colloids (2). Finally, after addition of ammonia, a silica shell is grown on the nanoparticle-decorated colloid by consecutive additions of tetraethoxysilane (3). (From Graf, G. et al. 2006. Langmuir 22 5604-5610. With permission.)... 

In addition to functionalizing native CPMV for electrochemical applications, Evans and coworkers utilized the exterior of CPMV as a biological template for the synthesis of inorganic nanoparticles.Silica nanoparticles were synthesized from a genetically mutated version of CPMV, which included the insertion of a 12 amino acid peptide sequence previously determined to initiate the nucle-ation of silica mineralization. The introduction of a short peptide into the viral capsid did not alter the assembly... 

Mann and coworkers proposed a unique method to prepare nanohybrids of mesoporous silica and gold nanoparticles mediated by programmed DNA hybridization, as illustrated in Figure 4.21 [186], MCM-41 nanoparticles were first functionalized with a 3 -amino-terminated 12-base single strand oligonucleotide... 

The second hierarchical level of the nanostructure (1—4nm) can be a rather complicated stmcture. It stabilizes the nanosized carrier by modifying the surface with biocompatible coverage (polyacrylamide, silica, hydroxyapatite, titanium, or aluminum oxide, etc.). The presence of a modifying layer retains a high specific surface of the nanoparticles and allows the necessary chemical functionalization, for example, with hydroxyl, carboxyl, thiol, and amino groups. 

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