Magnetic porous sugar-functionalized PEG microgels for efficient isolation and removal of bacteria from solution.

Here, we present a new microparticle system for the selective detection and magnetic removal of bacteria from contaminated solutions. The novelty of this system lies in the combination of a biocompatible scaffold reducing unspecific interactions with high capacity for bacteria binding. We apply highly porous poly(ethylene glycol) (PEG) microparticles and functionalize them, introducing both sugar ligands for specific bacteria targeting and cationic moieties for electrostatic loading of superparamagnetic iron oxide nanoparticles. The resulting magnetic, porous, sugar-functionalized (MaPoS) PEG microgels are able to selectively bind and discriminate between different strains of bacteria Escherichia coli . Furthermore, they allow for a highly efficient removal of bacteria from solution as their increased surface area can bind three times more bacteria than nonporous particles. All in all, MaPoS particles represent a novel generation of magnetic beads introducing for the first time a porous, biocompatible and easy to functionalize scaffold and show great potential for various biotechnological applications.

Synthesis of porous PEG microgels using CaCO3 microspheres as hard templates.

Porous poly(ethylene glycol) (PEG) microgels of both 17.6 and 8.3 µm in diameter are synthesized via hard templating with calcium carbonate (CaCO(3)) microparticles. The synthesis is performed in three steps: loading of PEG macromonomers into CaCO(3) microparticles, crosslinking via photopolymerization, and removal of the CaCO(3) template under acidic conditions. The resulting porous PEG microgels are inverse replicates of their templates as indicated by light microscopy, cryo-scanning electron microscopy (cryo-SEM), and permeability studies. Thus this process allows for the straightforward and highly reproducible synthesis of porous hydrogel particles of two different diameters and porosities that show great potential as carriers for drugs or nanomaterials.