1,720,972 research outputs found
Porous silica microshells from diatoms as biocarrier for drug delivery applications
No full textAbstract not availableMoom Sinn Aw, Spomenka Simovic, Yang Yu, Jonas Addai-Mensah, Dusan Losi
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
Highly ordered titania (TiO(2)) nanotube arrays fabricated by electrochemical self-ordering process toward development of implantable drug delivery devices with triggered drug release
No full textThe attractiveness of sell-ordered electrochemical synthesis of nanopore and nanotube arrays is based on its' simplicity, low cost and nanoscale precision to create highly-organized and uniform structures with controllable dimensions and unique properties. In this work the fabrication of titania nanotubes (TNT) array and their application as implantable drug delivery platform is explored. Prepared TNT were loaded with anti-inflammatory drug (indomethacin). Sustained drug release including triggered release by external magnetic field from TNT implant was monitored by UV-VIS and reflective interference spectroscopy.Karan Gulati, Spomenka Simovic and Dusan Losi
Silica-lipid hybrid (SLH) microcapsules: a novel oral delivery system for poorly soluble drugs
No full textAbstract not availableAngel Tan, Spomenka Simovic, Andrew K. Davey, Thomas Rades, Clive A. Prestidg
The Influence of Silica Nanoparticles On The Preparation and Stability of O/W Emulsions
No full textThe effect of silica nanoparticle addition on the stability of O/W emulsions initially stabilized by lecithin or oleylamine has been investigated. The synergy between silica nanoparticles and the emulsifiers at stabilizing the oil-water interface has been established. The influence of variation in the number of homogenization cycles, the ratio of emulsifier to silica, oil load and the initial location of nanoparticles on the size distribution of emulsion droplets have been studied. freeze-fracture scanning electron microscopy was used to study the interfacial structure of the emulsion droplets. The results confirm improvement in the long term physical stability of emulsions in the presence of silica nanoparticlesNasrin Ghouchi Eskandar, Spomenka Simovic, Anne Saupe, Thomas Rades, Clive A. Prestidg
Silica microcapsules from diatoms as new carrier for delivery of therapeutics
No full textAim: This study explores the use of natural silica-based porous material from diatoms, known as diatomaceous earth, as a drug carrier of therapeutics for implant- and oral-delivery applications. Materials & Methods: To prove this concept, two drugs models were used and investigated: a hydrophobic (indomethacin) and hydrophilic (gentamicin). Results & Discussion: Results show the effectiveness of diatom microcapsules for drug-delivery application, showing 14–22 wt% drug loading capacity and sustained drug release over 2 weeks. Two steps in the drug release from diatom structures were observed: the first, rapid release (over 6 h is attributed to the surface deposited drug) and the second, slow and sustained release over 2 weeks with zero order kinetics. Conclusion: These results confirm that natural material based on diatom silica can be successfully applied as a drug carrier for both oral and implant drug-delivery applications, offering considerable potential to replace existing synthetic nanomaterials.Moom Sinn Aw, Spomenka Simovic, Jonas Addai-Mensah & Dusan Losi
Platforms for controlled release of antibacterial agents facilitated by plasma polymerization
No full textBacterial infections present an enormous problem causing human suffering and cost burdens to the healthcare systems worldwide. Herein we present several versatile strategies for controlled release of antibacterial agents which include silver ions as well as traditional antibiotics. At the heart of these release platforms is a thin film deposited by plasma polymerization. The use of plasma polymerization makes these strategies applicable to the surface of many types of medical devices since the technique for deposition of a polymer film from plasma in practically substrate independent.Krasimir Vasilev, Spomenka Simovic, Dusan Losic, Hans J. Griesser, Stefani Griesser, Karine Anselme and Lydie Plou
The loading and release property of nanoporous anodic alumina for delivery of drugs and drug carriers
No full textA two-step electrochemical anodisation approach was adopted in this work to create a series of highly ordered mesopores etched with different diameter (60 to 160 nm) and uniform nanotube length in anodised aluminium oxide (AAO). The loading and release characteristics of model drug (indomethacin) and drug carriers (micelles named Pluronic F127, TPGS, PEO-PPO-PEO) were presented to investigate the influence of micelle size, pore diameter and surface modification of AAO on release studies. Surface chemistry was varied via silanation process, using AFTES and PFPTES. It was discovered that quicker release of drugs was induced by larger pore size and smaller micelles. Moreover drug release was found to favour hydrophobic surface as the release was faster in PFPTES modified AAO than the one with APTES.Moom Sinn Aw, Spomenka Simovic, Kumar Dhiraj, Jonas Addai-Mensah and 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
Controlled release from porous platforms
No full textThe authors present a method for controlling the release of therapeutics by applying a plasma polymer layer to the surface of porous materials. The current study applied this technique to the release of antibiotics and a protein. The approach substantially reduced the initial burst release and provided zero-order release kinetics. The method can be applied to any type of porous drug carrier because the techniques for depositing a polymer overlayer are independent of the substrate.Dusan Losic, Spomenka Simovic and Krasimir Vasile
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