Lipid-conjugated polysaccharide vesicles in nano- and micro-scale were developed from amphiphilic
octadecanol-modified dextrans (OMD) prepared by partial esterification of dextran with activated
octadecanol-carbamate imidazole in a well-controlled manner. The critical aggregation concentration
(CAC) of OMD adducts in aqueous phase varies, depending mainly on their octadecanol contents.
Through supramolecular assembly of the OMD adducts comprising either 17 or 28 mol% octadecanol
residues with respect to the anhydroglucopyranose units by the partial solvent displacement technique
with the initial water content of DMSO/H2O solutions beyond a critical point, stable nano-scaled OMD
assemblies were developed and characterized by the vesicle-like morphology. The dimension of polymersomes
can be effectively controlled by the OMD composition as well as the initial water content. On
the other hand, micro-scaled OMD polymersomes can be achieved by the double emulsion technique in
a water/oil/water (w1/o/w2) manner. Both the contents of NaCl in aqueous solution as the w1 phase and
of DMSO in DMSO/CHCl3 co-solvents as the organic phase, in which OMD was dissolved, are of great
importance in controlling the polymersome morphology and size. These micro-scaled OMD polymersome
walls are characterized by size-selective permeability capable of encapsulating large water-soluble
cargoes while allowing transport of small polar species across the membrane, thereby rendering these
unique colloidal particles of potential applications in biomedical technologies.
