| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.116 |
| 발표분야 | 생체적합성 유ㆍ무기 입자소재 |
| 제목 | Core/shell nanoparticles with drug-loaded lipid core |
| 초록 | In this study, a novel method for the preparation of core/shell nanoparticles with drug-loaded lipid core was designed and characterized. The lipid core is composed of lecithin, which forms a spherical supramolecular structure (multilamellar vesicles) in the concentrated state. The polymeric shell is composed of pluronics (poly (ethylene oxide)-poly (propylene oxide)-poly(ethylene oxide) triblock copolymer, F-127). The vesicular structures show their limited physical and biological stabilities and various attempts have been made to overcome these difficulties. These were done by modifying phospholipid with the incorporation of polymers with hydrophilic chains of various surfactants or of block copolymers. In this study, the stabilization of drug-loaded lipid core, which had a spherical vesicular structure, was performed by the formation pf polymeric shell on the surface of vesicles. For this purpose, the freeze-drying of drug-loaded lipid core was performed in the F-127 aqueous solution containing trehalose. Trehalose, which is an effective stabilizer of protein in solution as well as in the freeze-dried state, was used in order to preserve the integrity of lipid core during the freeze-drying. For the preparation of core-shell nanoparticles, a drug suspension composed of 90/10(w/w) (Tween 80/paclitaxel) mixture was prepared in which the oil phase was subsequently dispersed. The oil phase was composed of 40 weight % aqueous solution of lecithin from soy bean oil. The obtained drug dispersion and oil phase were mixed with equal amount and were then subjected to the sonication in the ice bath for 3 minutes to prepare drug-loaded lipid. The solution mixtures composed of 90/10(w/w) (F-127 aqueous solution/drug-loaded lipid core) were prepared to induce the formation of polymeric shell on the surface of drug-loaded lipid core. F-127 aqueous solutions were prepared with or without trehalose to observe the preservation of integrity of core/shell structure of nanoparticles during the freeze-drying. Particle size distributions of drug-loaded lipid core in the solution mixture and the core/shell nanoparticles after freeze-drying were analyzed using electrophoretic light scattering and TEM (Transmittance Electron Microscopy), which shows the formation of stabilized nanoparticles. The release pattern of paclitaxel from the nanoparticles was observed as a function of the concentration of F-127 aqueous concentration. Without the polymeric shell (0 weight % of F-127 aqueous solution), significant burst effect was observed resulting in the precipitation of paclitaxel into the release medium. With the formation of polymeric shell, the release rate was reduced significantly and almost zero-order release pattern was observed with nanoparticles formed from 10 weight % F-127 aqueous solution. With the adsorption of F-127 on the surface of lecithin core by freeze-drying, the stabilized core/shell nanoparticles were formed in the presence of trehalose. This indicates that trehalose, which is generally used as a protein stabilizer, preserves the integrity of a spherical supramolecular structure of lecithin core during the freeze-drying. Based on this characteristic, the core/shell nanoparticles with paclitaxel-loaded lipid core were prepared in the powdery state. The control of drug release rate from the nanoparticles indicates that the core/shell nanoparticles in this study can be utilized as a drug delivery carrier for hydrophobic drug. Especially, by considering the size of nanoparticles, the possibility of the passive targeting to the specific tumor cells is under study based on the enhanced permeation and retention (EPR) effect. |
| 저자 | 육순홍, 오근상 |
| 소속 | 한남대 |
| 키워드 | Core-shell nanospheres; Drug-loaded lipid core |
