title: Protein capsules assembled via isobutyramide grafts: sequential growth, biofunctionalization, and cellular uptake.
abstract: We report the sequential assembly of proteins via the alternating physical adsorption of human serum albumin (HSA) and chemical grafting with isobutyramide (IBAM) or bromoisobutyramide (BrIBAM) groups. This approach, performed on silica template particles, leads to the formation of noncovalent protein films with controlled growth at the nanometer scale. Further, after template removal, hollow protein capsules with tunable wall thicknesses and high mechanical stability are obtained. The use of BrIBAM, compared to IBAM grafts, leads to significantly thicker capsule walls, highlighting the influence of the bromine atoms in the assembly process, which is discussed in terms of a theoretical model of noncovalent interactions. Another feature of the process is the possibility to functionalize the HSA capsules with other biologically active macromolecules, including enzymes, polysaccharides, or DNA plasmids, demonstrating the versatility of this approach. We also report that BrIBAM-HSA and IBAM-HSA capsules display negligible cytotoxicity in vitro with HeLa cells and that their cellular uptake is dependent on the thickness of the capsule walls. These findings support the potential use of these protein capsules in tailored biological applications such as drug delivery.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Damien
authors.initials: D
authors.lastname: Mertz
authors.forename: Jiwei
authors.initials: J
authors.lastname: Cui
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Glyn
authors.initials: G
authors.lastname: Devlin
authors.forename: Christophe
authors.initials: C
authors.lastname: Chaubaroux
authors.forename: Alexandre
authors.initials: A
authors.lastname: Dochter
authors.forename: Roxane
authors.initials: R
authors.lastname: Alles
authors.forename: Philippe
authors.initials: P
authors.lastname: Lavalle
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Voegel
authors.forename: Anton
authors.initials: A
authors.lastname: Blencowe
authors.forename: Pascal
authors.initials: P
authors.lastname: Auffinger
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D000577:Amides / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D003460:Crystallization / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D008422:Materials Testing; D053769:Nanocapsules / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D010316:Particle Size; D012709:Serum Albumin / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D000577:Amides; D053769:Nanocapsules; D012709:Serum Albumin; C030197:isobutyramide