title: Controlling the nanostructure of gold nanorod-lyotropic liquid-crystalline hybrid materials using near-infrared laser irradiation.
abstract: Lipid-based liquid-crystalline matrixes provide a unique prospect for stimuli-responsive nanomaterials, attributed to the ability to effect self-assembly of the lipids at the molecular level. Differences in liquid crystal nanostructure have previously been shown to change drug diffusion and hence release, with research progressing toward the use of in situ changes to nanostructure to control drug release. Toward this goal, we have previously communicated the ability to switch between nonlamellar structures using gold nanorod (GNR)-phytantriol-based liquid-crystalline hybrid nanomaterials as near-infrared light responsive systems (Fong et al. Langmuir 2010, 26, 6136-6139). In this study, the effect of laser activation on matrix nanostructure with changes in a number of system variables including lipid composition, GNR aspect ratio, GNR concentration, and laser pulse time were investigated. The nanostructure of the matrix was followed using small-angle X-ray scattering, while both cryoFESEM and cryoTEM were used to visualize the effect of GNR incorporation into the liquid crystal nanostructure. The system response was found to be dependent on all variables, thus demonstrating the potential of these nanocomposite materials as reversible "on-demand" drug delivery applications.
authors.affiliation: Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences,  Monash University  (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Australia.
authors.forename: Wye-Khay
authors.initials: WK
authors.lastname: Fong
authors.forename: Tracey L
authors.initials: TL
authors.lastname: Hanley
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thierry
authors.forename: Nigel
authors.initials: N
authors.lastname: Kirby
authors.forename: Lynne J
authors.initials: LJ
authors.lastname: Waddington
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Boyd
mesh_terms: D005233:Fatty Alcohols / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D006859:Hydrogen / Q000737:chemistry; D007259:Infrared Rays; D007834:Lasers; D050866:Liquid Crystals / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D013997:Time Factors; D014810:Vitamin E / Q000737:chemistry
chemical_list: D005233:Fatty Alcohols; D014810:Vitamin E; D006046:Gold; D006859:Hydrogen; C508873:3,7,11,15-tetramethyl-1,2,3-hexadecanetriol