title: Fabrication of functional bioinorganic nanoconstructs by polymer-silica wrapping of individual myoglobin molecules.
abstract: Discrete core-shell hybrid nanoparticles comprising individual met-myoglobin (met-Mb) molecules incarcerated within an ultrathin polymer/silica shell were prepared without loss of biofunctionality by a facile self-assembly procedure. Solubilisation of met-Mb in cyclohexane in the near-absence of water was achieved by wrapping individual protein molecules in the amphiphilic triblock copolymer poly(ethylene-oxide)19-poly(propylene-oxide)69-poly(ethylene-oxide)19 (EO19-PO69-EO19, P123). Addition of tetramethoxysilane to the met-Mb/P123 conjugates in cyclohexane produced discrete nanoparticles that contained protein, polymer and silica, and which were 3-5.5 nm in size, consistent with the entrapment of single molecules of met-Mb. The hybrid nanoconstructs were isolated and re-dispersed in water without loss of secondary structure, and remained functionally active with respect to redox reactions and CO and O2 ligand binding at the porphyrin metallocentre. The incarcerated met-Mb biomolecules showed enhanced thermal stability up to a temperature of around 85 °C. These properties, along with the high biocompatibility of silica and P123, suggest that the silicified protein-polymer constructs could be utilised as functional nanoscale components in bionanotechnology.
authors.affiliation: Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
authors.forename: Biru
authors.initials: B
authors.lastname: Hu
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.forename: Sajanikumari
authors.initials: S
authors.lastname: Sadasivan
authors.forename: Avinash J
authors.initials: AJ
authors.lastname: Patil
authors.forename: Stephen
authors.initials: S
authors.lastname: Mann
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D003460:Crystallization / Q000379:methods; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D009211:Myoglobin / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D046911:Macromolecular Substances; D009211:Myoglobin; D011108:Polymers; D012822:Silicon Dioxide