Chemical cross-linking during spray
drying offers the potential
for green fabrication of microgels with a rapid stimuli response and
good blood compatibility and provides a platform for stimuli-responsive
hemicellulose microgels (SRHMGs). The cross-linking reaction occurs
rapidly in situ at elevated temperature during spray drying, enabling
the production of microgels in a large scale within a few minutes.
The SRHMGs with an average size range of ∼1–4 μm
contain O-acetyl-galactoglucomannan as a matrix and
poly(acrylic acid), aniline pentamer (AP), and iron as functional
additives, which are responsive to external changes in pH, electrochemical
stimuli, magnetic field, or dual-stimuli. The surface morphologies,
chemical compositions, charge, pH, and mechanical properties of these
smart microgels were evaluated using scanning electron microscopy,
IR, zeta potential measurements, pH evaluation, and quantitative nanomechanical
mapping, respectively. Different oxidation states were observed when
AP was introduced, as confirmed by UV spectroscopy and cyclic voltammetry.
Systematic blood compatibility evaluations revealed that the SRHMGs
have good blood compatibility. This bottom-up strategy to synthesize
SRHMGs enables a new route to the production of smart microgels for
biomedical applications.