earticle

영어

Multi stimuli-sensitive drug delivery system using poly(ethyleneimine)(PEI) and cinnamic acid(CA) was prepared by self-assembly. PEI and CA are combined by electrostatic attraction to form a conjugate. Since PEI is hydrophilic and CA is hydrophobic, the conjugate exhibits amphipathic properties. Thus, the conjugate forms a self-assembly in aqueous solution. The formed self-assembly is characterized by its response to various stimuli (pH, temperature, UV). In the case of pH, PEI/CA forms a self-assembly at acidic pH. However, as the pH increases, the degree of ionization of PEI decreases, and the electrostatic attraction between PEI and CA decreases so that the self-assembly is disassembled. In the case of temperature, PEI/CA forms a self-assembly at room temperature, but when the temperature increases, the PEI/CA conjugate decreases in amphipathicity as the solubility of CA increases, self-assembly is disassembled. In the case of UV, when UV light is applied to the self-assembly, CA is isomerized from trans to cis and the self-assembly is disassembled. The self-assembly having the multi stimuli-sensitive characteristic can be applied to the cubic phase, which is a lipid structure. In addition, gold nanoparticle (GNP) representing the surface plasmon resonance phenomenon can be added to the cubic phase to give a response characteristic to NIR. The cubic phase consists of lipid bilayer and water channel. The self-assembly is contained on the water channel and the GNP is inserted into the lipid bilayer. When the NIR are irradiated on the cubic phase, the solubility of CA is increased because the GNP generates heat due to the surface plasmon resonance. As a result, the self-assembly which blocks the inside of the water channel of cubic phase is disassembled and the contents are released.