Amphiphilic Chitosan---Crystalline Silica Hybrid Macromolecules: Molecular Design, Self-Assembly Behavior, and Drug Delivery

• Main Authors: Tung, Tsan-Hua, 董簪華
• Other Authors: Liu, Dean-Mo
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/48737019443662912918

碩士 === 國立交通大學 === 材料科學與工程學系 === 98 === An organic-inorganic hybrid molecule, which was synthesized by anchoring a silane coupling agent, (3-aminopropyl)triethoxysilane, to an amphiphatic carboxymethyl-hexanoyl chitosan (termed as CHC) previously-developed from this lab, was demonstrated an adjustable self assembling capability in aqueous solution. The chemical structure of this novel hybrid molecule was characterized by FTIR and 13C-, 29Si-nuclear magnetic resonance. The self-assemble behavior of the hybrid macromolecules was characterized by critical aggregation concentration (CAC) measurements which demonstrated a concentration-dependent assembly behavior. Structural morphology of the hybrid nanoparticles was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scatter (DLS). A crystalline silica layer of ~6 nm in thickness was microscopically observed with a silica-CHC-silica layer-like architecture forming the hybrid nanoparticles. Such a highly-ordered silica lattice has been one of the most interesting phenomena ever reported forming under ambient, aqueous environment. Formation of the continuous crystalline silica layer also proved a cross-linker-free irreversible self-assembly behavior of the hybrid molecule compared with existing chitosan-based composite macromolecules. The hybrid macromolecule showed excellent encapsulation efficiency greater than 91% for an anti-cancer, hydrophobic molecule, (S)-(+)-Camptothecin. Its outstanding cytocompatibility and efficient cellular internalization towards the ARPE-19 cell line, associated with its structural stability under diluted condition, suggest a promising nanovehicle for drug delivery application.