title: Engineering advanced capsosomes: maximizing the number of subcompartments, cargo retention, and temperature-triggered reaction.
abstract: Advanced mimics of cells require a large yet controllable number of subcompartments encapsulated within a scaffold, equipped with a trigger to initiate, terminate, and potentially restart an enzymatic reaction. Recently introduced capsosomes, polymer capsules containing thousands of liposomes, are a promising platform for the creation of artificial cells. Capsosomes are formed by sequentially layering liposomes and polymers onto particle templates, followed by removal of the template cores. Herein, we engineer advanced capsosomes and demonstrate the ability to control the number of subcompartments and hence the degree of cargo loading. To achieve this, we employ a range of polymer separation layers and liposomes to form functional capsosomes comprising multiple layers of enzyme-loaded liposomes. Differences in conversion rates of an enzymatic assay are used to verify that multilayers of intact enzyme-loaded liposomes are assembled within a polymer hydrogel capsule. The size-dependent retention of the cargo encapsulated within the liposomal subcompartments during capsosome assembly and its dependence on environmental pH changes are also examined. We further show that temperature can be used to trigger an enzymatic reaction at the phase transition temperature of the liposomal subcompartments, and that the encapsulated enzymes can be utilized repeatedly in several subsequent conversions. These engineered capsosomes with tailored properties present new opportunities en route to the development of functional artificial cells.
authors.affiliation: Centre for Nanoscience and Nanotechnology, Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Rona
authors.initials: R
authors.lastname: Chandrawati
authors.forename: Leticia
authors.initials: L
authors.lastname: Hosta-Rigau
authors.forename: Dirk
authors.initials: D
authors.lastname: Vanderstraaten
authors.forename: Shalitha A
authors.initials: SA
authors.lastname: Lokuliyana
authors.forename: Brigitte
authors.initials: B
authors.lastname: Städler
authors.forename: Fernando
authors.initials: F
authors.lastname: Albericio
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D048908:Aliivibrio fischeri / Q000201:enzymology; D032701:Biomimetics / Q000379:methods*; D004738:Engineering / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D001618:beta-Lactamases / Q000737:chemistry / Q000378:metabolism
chemical_list: D008081:Liposomes; D011108:Polymers; D012822:Silicon Dioxide; D001618:beta-Lactamases