Magnetic assembly and patterning of vesicle/nanoparticle aggregates

As part of efforts aiming to create biomaterials that mimic tissue, patterned vesicle assemblies composed of phospholipid vesicles cross-linked by magnetic nanoparticles have been developed. Multivalent binding between synthetic adhesive lipids in the vesicle membranes and histidine-coated magnetite nanoparticles resulted in the reversible formation of large nanoparticle/vesicle aggregates. The nanoparticles did not insert into or otherwise disrupt the integrity of the vesicle membrane and the cross-linked vesicles retained encapsulated substances. These vesicle/nanoparticle aggregates could be manipulated by external magnetic fields to form patterned vesicle assemblies; for example, they were compressed to form layered materials reminiscent of tissue or compacted within separate chambers of a microflow cell.