Fabrication of phospholipid-xanthan microcapsules by combining microfluidics with self-assembly

We report the synthesis of an amphiphilic polysaccharide, a phospholipid (1,2-dioleoyl-sn-glycerophosphoetilamine,
DOPE) conjugated with the anionic xanthan gum, and its ability to spontaneously
self-assemble under mild aqueous conditions. This work also aimed to apply a microfluidic platform that
can precisely fabricate microsized and monodispersed capsules for cell encapsulation. Stable hollow
capsular structures were obtained by the generation of homogeneous spherical droplets of the selfassembled
polymer in the microfluidic device through the formation of a water-in-oil emulsion, followed
by the stabilization of the polymer aggregates in a separate collection vessel containing phosphatebuffered
saline (physiological ionic strength and pH). The properties (size, morphology, permeability)
and performance (stability) of the obtained microcapsules were studied, as well their ability to support
the viability, function and proliferation of encapsulated cells. ATDC5 cells were encapsulated within the
capsules and shown to remain viable, evidencing increased cellular metabolic activity over 21 days of
in vitro culture. By combining microfluidic droplet generation and self-assembly of xanthan–DOPE, we
were able to fabricate microcapsules that provided an adequate environment for cells to survive and
proliferate.