title: In vitro-reassembled plant virus-like particles for loading of polyacids.
abstract: The coat protein (CP) of certain plant viruses may reassemble into empty virus-like particles (VLPs) and these protein cages may serve as potential drug delivery platforms. In this paper, the production of novel VLPs from the Hibiscus chlorotic ringspot virus (HCRSV) is reported and the capacity to load foreign materials was characterized. VLPs were readily produced by destabilizing the HCRSV in 8 M urea or Tris buffer pH 8, in the absence of calcium ions, followed by removal of viral RNA by ultrahigh-speed centrifugation and the reassembly of the CP in sodium acetate buffer pH 5. The loading of foreign materials into the VLPs was dependent on electrostatic interactions. Anionic polyacids, such as polystyrenesulfonic acid and polyacrylic acid, were successfully loaded but neutrally charged dextran molecules were not. The molecular-mass threshold for the polyacid cargo was about 13 kDa, due to the poor retention of smaller molecules, which readily diffused through the holes between the S domains present on the surface of the VLPs. These holes precluded the entry of large molecules, but allowed smaller molecules to enter or exit. The polyacid-loaded VLPs had comparable size, morphology and surface-charge density to the native HCRSV, and the amount of polyacids loaded was comparable to the weight of the native genomic materials. The conditions applied to disassembly-reassembly of the virions did not change the structural conformation of the CP. HCRSV-derived VLPs may provide a promising nano-sized protein cage for delivery of anionic drug molecules.
authors.affiliation: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117543.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Adjunct Investigator, Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604.|Department of Biological Sciences, National University of Singapore, 18 Science Drive 4, Singapore 117543.
authors.forename: Sek-Man
authors.initials: SM
authors.lastname: Wong
authors.affiliation: Pharmacy, School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley, WA 6009, Australia.|Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117543.
authors.forename: Lee-Yong
authors.initials: LY
authors.lastname: Lim
mesh_terms: D000143:Acids / Q000008:administration & dosage*; D000180:Acrylic Resins / Q000008:administration & dosage; D036022:Capsid Proteins / Q000378:metabolism; D019184:Carmovirus / Q000502:physiology; D003911:Dextrans / Q000008:administration & dosage; D016503:Drug Delivery Systems; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives; D006863:Hydrogen-Ion Concentration; D008854:Microscopy, Electron; D010942:Plant Viruses / Q000502:physiology*; D011108:Polymers / Q000008:administration & dosage*; D011137:Polystyrenes / Q000008:administration & dosage; D055672:Static Electricity; D014771:Virion / Q000502:physiology; D019065:Virus Assembly
chemical_list: D000143:Acids; D000180:Acrylic Resins; D036022:Capsid Proteins; D003911:Dextrans; D011108:Polymers; D011137:Polystyrenes; C015219:fluorescein isothiocyanate dextran; C006903:carbopol 940; C003321:polystyrene sulfonic acid; D016650:Fluorescein-5-isothiocyanate