1,720,972 research outputs found
Surface functionalisation of diatoms with dopamine modified iron-oxide nanoparticles: toward magnetically guided drug microcarriers with biologically derived morphologies
No full textDiatom silica microcapsules prepared by purification of diatomaceous earth (DE) were functionalised by dopamine modified iron-oxide nanoparticles, in order to introduce diatoms with magnetic properties. The application of magnetised diatoms as magnetically guided drug delivery microcarriers has been demonstrated.Dusan Losic, Yang Yu, Moom Sinn Aw, Spomenka Simovic, Benjamin Thierry and Jonas Addai-Mensa
Advanced biopolymer-coated drug-releasing titania nanotubes (TNTs) implants with simultaneously enhanced osteoblast adhesion and antibacterial properties
Full text linkAbstract not availableTushar Kumeria, Htwe Mon, Moom Sinn Aw, Karan Gulati, Abel Santos, Hans J. Griesser, Dusan Losi
Polymeric micelles in porous and nanotubular implants as a new system for extended delivery of poorly soluble drugs
No full textData source: Supplementary information, https://doi.org/10.1039/C0JM04307ANanopore and nanotube structures such as anodic aluminium oxide (AAO) and nanotubular titania (TNT) prepared by self-ordering electrochemical anodization have attracted considerable attention for the development of new implant devices and drug delivery applications. In this work, we present a new implantable drug delivery system that integrates polymer micelles as drug nanocarrier and nanoporous structure to achieve an extended delivery of poorly water soluble drugs. Two strategies for controlled release of nanocarriers from AAO and TNT platforms were explored: (i) the influence of pore diameters of AAO (65 nm to 160 nm) and nanocarrier diameters (15–75 nm) and (ii) application of thin film-plasma polymer layer on the surface of porous material. By varying pore and polymer micelles diameters a two-phase release kinetics with burst release of 31–55% in the first 6–8 h followed by the slow phase, spanning across 8–22 days were obtained. Nevertheless, although results were improved by varying pore diameters, it is still not the optimal strategy to achieve a slow release of drug nanocarriers from porous platforms. More effective method to achieve their extended release with zero-order kinetics was demonstrated using plasma polymerisation method, in which complete release of micelles was found to be delayed to 27–31 days, with a significantly lowered burst release (12–15%).Moom Sinn Aw, Spomenka Simovic, Jonas Addai-Mensah and Dusan Losi
Drug-eluting Ti wires with titania nanotube arrays for bone fixation and reduced bone infection
Full text linkCurrent bone fixation technology which uses stainless steel wires known as Kirschner wires for fracture fixing often causes infection and reduced skeletal load resulting in implant failure. Creating new wires with drug-eluting properties to locally deliver drugs is an appealing approach to address some of these problems. This study presents the use of titanium [Ti] wires with titania nanotube [TNT] arrays formed with a drug delivery capability to design alternative bone fixation tools for orthopaedic applications. A titania layer with an array of nanotube structures was synthesised on the surface of a Ti wire by electrochemical anodisation and loaded with antibiotic (gentamicin) used as a model of bone anti-bacterial drug. Successful fabrication of TNT structures with pore diameters of approximately 170 nm and length of 70 μm is demonstrated for the first time in the form of wires. The drug release characteristics of TNT-Ti wires were evaluated, showing a two-phase release, with a burst release (37%) and a slow release with zero-order kinetics over 11 days. These results confirmed our system's ability to be applied as a drug-eluting tool for orthopaedic applications. The established biocompatibility of TNT structures, closer modulus of elasticity to natural bones and possible inclusion of desired drugs, proteins or growth factors make this system a promising alternative to replace conventional bone implants to prevent bone infection and to be used for targeted treatment of bone cancer, osteomyelitis and other orthopaedic diseases.Karan Gulati, Moom Sinn Aw and Dusan Losi
Polymer micelles for delayed release of therapeutics from drug-releasing surfaces with nanotubular structures
No full textData source: Supporting information, http://onlinelibrary.wiley.com/doi/10.1002/mabi.201200012/abstractA new approach to engineer a local drug delivery system with delayed release using nanostructured surface with nanotube arrays is presented. TNT arrays electrochemically generated on a titanium surface are used as a model substrate. Polymer micelles as drug carriers encapsulated with drug are loaded at the bottom of the TNT structure and their delayed release is obtained by loading blank micelles (without drug) on the top. The delayed and time-controlled drug release is successfully demonstrated by controlling the ratio of blank and drug loaded-micelles. The concept is verified using four different polymer micelles (regular and inverted) loaded with water-insoluble (indomethacin) and water-soluble drugs (gentamicin).Moom Sinn Aw, Jonas Addai-Mensah, Dusan Losi
Local drug delivery to the bone by drug-releasing implants: perspectives of nano-engineered titania nanotube arrays
No full textTitania nanotube (TNT) arrays fabricated by electrochemical anodization of titanium are currently one of the most attractive nanomaterials due to their remarkable properties. In this review, we highlight recent research activities that are focused on the application of the TNT arrays for local drug delivery, specifically for addressing problems associated with orthopedic implants. The advantages of drug-releasing implants based on TNT arrays for local delivery of therapeutics in bone related to these challenging problems including inflammation, infection and osseointegration are discussed. An overview of recent research to advance the drug-releasing performance of TNT arrays and the potential of their future applications and development are presented.Karan Gulati, Moom Sinn Aw, David Findlay and Dusan Losi
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