Anticancer Effect of Intracellular-Delivered Doxorubicin Using a Redox-responsive LMWSC-g- Lipoic Acid Micelles

다국어 초록 (Multilingual Abstract)

To induce a quick-drug release, lipoic acid (LA) was introduced to amine group of low molecular-weight water soluble chitosan (LMWSC) by chemical reaction with EDC as coupling agent. The disulfide bond (-S-S-) of lipoyl group from LMWSC-g-LA (LL) can response to glutathione (GSH) at cytoplasm with reducing environment, which LL can rapidly be disassembled via dissociation of disulfide bond (-S-S-) by GSH. The doxorubicin (DOX) as anticancer drug was encapsulated to LL by dialysis method. The DOX of DOX-encapsulated LL (LLDOX) may be quickly released by destabilization of inner-hydrophobic core of LL when disulfide bond (-S-S-) of inner-hydrophobic core of LL was dissociated by GSH. The chemical structure of redox-responsive LL was analyzed by 1H-NMR and FT-IR. From these results, we found that LL was successfully synthesized. The particle size and morphology of LL and LLDOX were respectively confirmed by DLS and TEM. The particle size of LL30% and LL60% is a 268.8±30.9 and 308.1±11.9nm, respectively. In addition, particle size of LLDOX was decreased more than LL. Also, surface charge of LLDOX was displayed to strong positive charge (LLDOX30%: 12.6±0.5, LLDOX60%: 9.6±1.1). Moreover, their morphological structure has a spherical shape. The drug release of LLDOX was accomplished under PBS buffer (pH 7.4) and GSH (10 mM) condition to demonstration a redox-responsive release behavior. The cytotoxicity LL and LLDOX were confirmed by using MTT assay after the incubated in HEK293, HeLa, and AGS cell lines for 48 h. Besides, to investigate an intracellular uptake of DOX from LLDOX against HeLa and AGS cell lines, fluorescence image was observed by using fluorescence microscopy. These results suggest that LL is an excellent as
drug carrier due to high anticancer effect by rapid drug release with redox-responsive effect.

목차 (Table of Contents)

• І. Introduction 1
• Ⅱ. Materials and Methods 4
• 2.1. Materials 4
• 2.2 Methods 5
• Ⅲ. Results & Discussion 14
• 3.1. Synthesis and characterization of LMWSC-g-Lipoic acid (LL) 14
• 3.2. Preparation and characterization of LL nanoparticle 19
• 3.3. Preparation and characterization of doxorubicin-loaded LL(LLDOX) nanoparticles 24
• 3.4. In-vitro redox-responsive drug release profile of LLDOX nanoparticles by glutathione (GSH) 27
• 3.5. Cytotoxicity and anticancer activity of LL and LLDOX 31
• 3.6. Intracellular uptake of LLDOX nanoparticles 34
• Ⅳ. Conclusion 37
• References 39
• List of Publications 47