Methacryloyl(MA) 그룹이 유도된 dextran(dex-MA)을 이용한 microsphere는 코팅, 인쇄, 의약 산업 등에 널리 활용되고 있다. 본 연구에서는 Dex-MA, polyethylene glycol(PEG) 등의 고분자와 물로 구성된 수용액의 고분자 액-액 상분리 현상을 이용하여 dextran(Dex) microsphere를 제조하였으며 이들의 제조에 미치는 영향과 특성에 대해 알아보았다. Dex-MA는 transesterification반응을 통해 제조되었으며, 1H NMR, 13C NMR, FT-IR, GPC 등을 이용하여 그 반응특성을 관찰하였다. MA 그룹의 치환된 양(degree of substitution; DS)은 1H NMR의 피크 강도로부터 계산하였으며, 질량수지에 의한 계산값과 비교하였다. ATPS를 이용한 에멀젼법을 사용하여 microsphere를 제조하였으며, 이를 위해 필요한 25 ℃의 Dex-MA/PEG/물 계의 액-액 상평형 도표는 실험을 통하여 결정하였다. 본 연구에서는 에멀젼 법을 이용하여 직경이 7.7-38 μm인 microsphere를 재현성있게 제조할 수 있었다. 계산된 DS가 microsphere의 제조와 특성에 미치는 영향을 조사하였으며, 팽윤 특성은 질량법과 Blue-Dex 용액법을 사용하여 측정하였다.

Dextran-based microspheres have become growingly attractive in the fields of surface coating, printing, pharmaceutical and other industrial applications. In an effort to prepare the dextran-based microspheres, methacryloyl(MA) groups were introduced into dextran(Dex-MA) molecules as a crosslinking functional group via the transesterification reaction. The resulting Dex-MA was characterized by use of 1H NMR, 13C NMR, FT-IR, and GPC. Degree of substitution(DS) of the MA groups in the glucopyranose ring of a dextran molecule was calculated from peak intensities of 1H NMR spectrum and compared well with the calculated value. The aqueous two-phase polymer system(ATPS) emulsion, which consists of Dex-MA,_x000D_ PEG, and water, was used for preparation of the microspheres. To this purpose, the phase diagrams of several Dex-MA/PEG/water systems at 25 ℃ were constructed. Microparticles with a volume mean diameter from 7.7 to 38 μm could be prepared in a reproducible way. The DS could be used to tailor the size, the initial water content, and the swelling property of the resulting_x000D_ microspheres. In addition, the swelling properties of the microspheres were measured by means of the blue-Dex solution method and the gravimetric method.

Dextran Hydrogels Dextran Microspheres Blue-Dex Solution Method Methacryloyl ATPS

Park KN, Shalaby SW, Park HS, "Biodegradable Hydrogels for Drug Delivery," Technomic Publishing Co., Inc., Lancaster, PA (1993)
"Proceeding of the Tailored Polymeric Materials for Controlled Delivery Systems-sept. 7, 1997," ACS publications, Chapter 2 (1998)
Beltran S, Baker JP, Hooper HH, Blanch HW, Prausnitz JM, Macromolecules, 24, 549 (1991) 
Gehrke SH, Vaid NR, McBride JF, Biotechnol. Bioeng., 58(4), 416 (1998) 
Kapur V, Charkoudian JC, Kessler SB, Anderson JL, Ind. Eng. Chem. Res., 35(9), 3179 (1996) 
Motozato Y, Ihara H, Tomada T, Hirayama C, J. Chromatogr., 355, 434 (1986) 
Horgaard L, Brondsted H, J. Control. Release, 36, 159 (1995) 
Franssen O, Stenekes RJH, Hennink WE, J. Control. Release, 59, 219 (1999) 
Vandijkwolthuis WN, Franssen O, Talsma H, Vansteenbergen MJ, Vandenbosch JJ, Hennink WE, Macromolecules, 28(18), 6317 (1995) 
Vandijkwolthuis WN, Kettenesvandenbosch JJ, Vanderkerkvanhoof A, Hennink WE, Macromolecules, 30(11), 3411 (1997) 
Albetsson PA, Nature, 182, 709 (1958) 
Cho JM, Kang CH, J. Research Inst. Catal., 21, 105 (2000)
Stenekes RJH, Franssen O, van Bommel EMG, Crommelin DJA, Hennink WE, Pharm. Res., 15, 557 (1998) 
Franssen O, Hennink WE, Int. J. Pharm., 168, 1 (1998) 
Stenekes RJH, Franssen O, van Bommel EMG, Crommelin DJA, Hennink WE, Int. J. Pharm., 183, 29 (1999)