Multifunctional Compartmentalized Capsules with a Hierarchical Organization from the Nano to the Macro Scales

Inspired by the cells’ structure,
we present compartmentalized
capsules with temperature and magnetic-based responsiveness and hierarchical
organization ranging from the nano- to the visible scales. Liquefied
alginate macroscopic beads coated with a layer-by-layer (LbL) chitosan/alginate
shell served as containers both for model fluorophores and microcapsules,
which in their turn encapsulated either another fluorophore or magnetic
nanoparticles (MNPs). The microcapsules were coated with a temperature-responsive
chitosan/elastin-like recombinamer (ELR) nanostructured shell. By
varying the temperature from 25 to 37 °C, the two-hour release
of rhodamine encapsulated within the microcapsules and its diffusion
through the external compartment decreased from 84% and 71%. The devices
could withstand handling and centrifugal stress, with 50% remaining
intact at a rotation speed of 2000g. MNPs attributed
magnetic responsiveness toward external magnetic fields. Such a customizable
system can be envisaged to transport bioactive agents and cells in
tissue engineering applications.