title: Sustained release from mesoporous nanoparticles: evaluation of structural properties associated with release rate.
abstract: We present here a detailed study of the controlled release of amino acid derived amphiphilic molecules from the internal pore structure of mesoporous nanoparticle drug delivery systems with different structural properties; namely cubic and hexagonal structures of various degrees of complexity. The internal pore surface of the nanomaterials presented has been functionalised with amine moieties through a one pot method. Release profiles obtained by Alternating Ionic Current measurements are interpreted in terms of specific structural and textural parameters of the porous nanoparticles such as pore geometry and connectivity. Results indicate that diffusion coefficients are lower by as much as four orders of magnitude in 2-dimensional structures in comparison to 3-dimensional mesoporous solids. A fast release in turn is observed from mesocaged materials AMS-9 and AMS-8 where the presence of structural defects is thought to lead to a slightly lower diffusion coefficient in the latter. Amount of pore wall functionalisation and number of binding sites on the model drug are found to have little effect on the drug release rate.
authors.affiliation: Department of Engineering Sciences, The Angström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Brohede
authors.forename: Rambabu
authors.initials: R
authors.lastname: Atluri
authors.forename: Alfonso E
authors.initials: AE
authors.lastname: Garcia-Bennett
authors.forename: Maria
authors.initials: M
authors.lastname: Strømme
mesh_terms: D000465:Algorithms; D003692:Delayed-Action Preparations; D004553:Electric Conductivity; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D013816:Thermodynamics; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D003692:Delayed-Action Preparations; D009584:Nitrogen