Abstract:

Mesoporous silicas of AMS-8-NH₂ have been synthesized with the anionic surfactant N-myristoyl-L-glutamic acid sodium(C₁₄ GluA-Na) and 3-amino propyltrimethoxy silane(APS) as co-structure-directing agents(CSDA). The materials were characterized by powder X-ray diffraction(XRD), N₂ adsorption/desorption analysis and ²⁹Si magic angle spinning nuclear magnetic resonance(MAS NMR). The results exhibit that the structure of AMS-8-NH₂ has a long range order of three-dimensional cage-like connecting aperture with about 3.2 nm pore diameter and 706 m²/g special surface area respectively nano-hole material. Organic amine groups have anchored chemically to the surface of material through chemical bonding, whose coverage has reached 25%. The resulting AMS-8-NH₂ materials were used as vehicles and herring sperm oligodeoxyneucleotide(ODN) as a model biological molecule for discussing the loading and release character of ODN on AMS-8-NH₂. The loading experiment shows that when the solution concentration is fixed, the higher solution acidity, the higher loading capability and the maximum amount can reach 214 mg/g at pH=4.7. Among the release process, high sustained release effect of ODN on materials is displayed, which is controlled by environmental pH value. The greater the pH value, the higher the release amount.

Key words: Mesoporous silicas of AMS-8-NH2; Oligodeoxyneucleotide(ODN); Adsorption; Release