Self-assembly and encapsulation behaviors of block copolymers in small molecule drugs
Date Issued
2012
Date
2012
Author(s)
Chuang, Yu-Hao
Abstract
It is well known that amphiphilic block copolymers in selective solvents
self-assemble into micellar structures, where solvophilic blocks tend to contact with
solvents while solvophobic blocks are shielded from the solvents. Different from the
conventional micellization in liquid systems, we found that the block copolymers
poly(styrene-block-ethylene oxide) (PS-b-PEO) can self-assemble into a variety of
structures in melted 3-n-pentadecylphenol (PDP), benzoic acid and acetylsalicylic
acid (Aspirin) at high temperature and the structures are retained in “solid state” after
being cooled down to room temperature. We further found that such solid-state
structures can be obtained by solvent annealing at room temperature or 45 ℃, which
prevents unnecessary chemical reactions at high temperature especially for drug
molecules. The structures that are trapped in solid state can be extracted entirely by
using appropriate solvents. Compared with vesicles formed in liquid systems, the
extracted vesicles, which are filled with small molecules in the core, are highly
efficient to encapsulate substances and potential for the application of controlled
release. Besides, the morphologies are dependent on the relative length of the block
copolymers and the annealing time, which influence the packing of the copolymer
chains and the inherent molecular curvature.
Subjects
Self-assembly
Block copolymers
Micelles
Vesicles
Aspirin
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-101-R99549005-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):b68744feaec3581d191dbfe37ea99f9d