• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2342-2348
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• 2014

Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic$^{(R)}$ F68 ($(EO)_{75}(PO)_{30}(EO)_{75}$) triblock copolymer to produce poly{(lactic acid)$_m$-co-(glycolic acid)$_n$}-b-poly(ethylene oxide)$_{75}$-b-poly(propylene oxide)$_{30}$-b-poly(ethylene oxide)$_{75}$-b-poly{(lactic acid)$_m$-co-(glycolic acid)$_n$} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate ($Sn(Oct)_2$) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by $^1H$- and $^{13}C$-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with $^1H$-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:$H_2O$ = 10:90 by volume at $25^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• 제34권3호
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• pp.177-183
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• 2004

Recently, studies on intranasal mucosa delivery of influenza vaccine have been actively developed because of lack of pain and ease of administration. We studied on preparation of nanoparticle delivery system using biodegradable polymer as a poly(DL-lactide-co-glycolide) (PLGA) and their binding characteristics with vaccine. Three kinds of PLGA nanoparticles were prepared by spontaneous emulsification solvent diffusion (SESD) method using sodium dodecyl sulfate and sodium laurate as an anionic surfactant and Lutrol F68 (polyethylene glycol-block-polypropylene glycol copolymer) as a nonionic surfactant. The 5-aminofluorescein labeled vaccine was coated on the surface of nanoparticles by ionic complex. The complexes between vaccine and nanoparticles were confirmed by change of the size. After vaccine coating on the surface of anionic nanoparticles, particle size was increased from 174 to 1,040 nm. However the size of nonionic nanoparticles was not more increased than size of anionic nanoparticles. The amount of coated vaccine on the surface of PLGA nanoparticles was $14.32\;{\mu}g/mg$ with sodium dodecyl sulfate, $12.41\;{\mu}g/mg$ with sodium laurate, and $9.47{\mu}g/mg$ with Lutrol F68, respectively. In conclusion, prepared nanoparticles in this study is possible to use as a virus-like nanoparticles and it could be accept in the field of influenza vaccine delivery system.

• 대한화학회지
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• 제47권6호
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• pp.601-607
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• 2003

생분해성 고분자인 poly(DL-lactide-co-glycolide)(PLGA)를 자발적 유화용매 확산(spontaneous emulsification solvent diffusion, SESD)법을 이용하여 표면이 양이온으로 수식된 나노입자로 제조하고 그 특성을 조사하였다. 고분자 용액은 에탄올과 아세톤의 이종 혼합 용매를 사용하였고, 유화제는 양이온성 유화제인 cetyltrimethylammonium chloride(CTAC), tetradecyltrimethylammonium bromide(TTAB)와 비이온성 유화제인 polyethylene glycol-block-polypropylene glycol 공중합체(Lutrol F68)를 사용하였다. 제조한 입자에 결합한 백신은 인플루엔자($H_3N_2,\;H_1N_1$, B strain)이었고 입자에 대한 백신의 코팅 양은 NHS-fluorescein을 사용하여 확인하였다. 양이온성과 비이온성 유화제가 표면에 수식된 입자의 크기는 160-180 nm와 80-90 nm이었고 제타포텐셜은 $50{\sim}60$ mV, -10 mV이었다. 백신 코팅 후 입자의 크기는 양이온성이 380-400 nm, 비이온성은 별다른 크기 변화가 없었다. 양이온이 수식된 입자에 코팅된 백신의 양은 22.73 ${\mu}g$/mg이었다.