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

Abstract

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.