322,958 research outputs found
Controlled drug release from porous materials by plasma polymer deposition
No full textData source: Supplementary files, https://www.rsc.org/suppdata/cc/b9/b919840g/b919840g.pdfIn this communication, we present a novel approach for control of drug release from porous materials. The method is based on deposition of a plasma polymer layer with controlled thickness which reduces a pore diameter and, hence, defines the rate of drug release.Spomenka Simovic, Dusan Losic and Krasimir Vasile
Ordered mesoporous materials for drug delivery applications
No full textConventional drug therapy is associated with a number of challenges, such as poor drug stability and/or solubility in biological environment, lack of selectivity, severe toxicity and unfavourable pharmacokinetics. The application of nanotechnology to medical devices - "nanomedicine" is recognized as an emerging field with huge potential for development of new therapeutic concepts. Research on mesoporous materials for biomedical purposes has experienced an outstanding increase during recent years. Three major types of mesoporous materials for drug delivery application were emerged including: mesoporous silica engineered by organic synthesis and porous silicon, anodically oxidised alumina (AAO) and nanotubular titania fabricated by electrochemical methods. Although still in early stages, few in vivo studies clearly show the potential of these materials for drug delivery devices in orthopedics implants, dental implants, and vascular stents, where not only is the controlled release of drugs such as antibiotics or growth factors desired, but also appropriate biointegration is needed. In this chapter we collect and analyze some of the most relevant milestones in the research of mesoporous materials for controlled drug delivery for implantable and systemic delivery systems. To provide a comprehensive overview to the reader, this review firstly analyzes biocompatibility aspects, which are the major prerequisite for application of materials that come into contact with biological systems. Secondly, we consider the basic aspects of the textural properties (surface and porosity) that contribute to the understanding of drug adsorption and controlled release processes. Finally, more sophisticated stimuli-responsive materials are reviewed. This is only beginning of the further research in terms of correlating biomaterial chemistry and tissue responses and new clinical approaches required not only for orthopaedics, but also treatment for a number of other diseases (hearth, cancer, diabetes, Parkinson's, Alzheimer's etc)Spomenka Simovic 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
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
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
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
Cumulus cell determinants of oocytes developmental competence
No full textA third of women undergoing oncological treatment is at risk of premature ovarian failure. In vitro maturation of denuded fullygrown antral oocytes (DOs) to metaphase II in the presence of cumulus cells (CCs) and their further cryopreservation is a strategy for preserving women fertility.1,2 Attempts have been made to culture DOs upon a feeder layer of CCs (FL-CCs) with meager results.3-5 The purpose of this study was to test whether a selection of CCs prior to the preparation of the FL improves the quality of oocytes maturation. We classified CCs based on their association with developmentally competent (SN) or incompetent (NSN) mouse fully-grown antral oocytes and prepared a FL-SNCCs or FL-NSN-CCs, respectively. We show that maturation of DOs upon FL-SN-CCs significantly better contributes to the acquisition of oocytes meiotic and developmental competence, with a developmental rate to blastocyst equal to that obtained after the maturation of intact cumulus oocyte complexes. Instead, DOs matured in the absence of CCs (NO-FL) or upon FL-NSN-CCs undergo meiotic and developmental failure, with embryos arresting either at the 4-cell or morula stage. Our experiments suggest the presence of a crucial developmental CC-factor/s released in the presence of FL-SN-CCs during oocyte maturation. These results set the bases to unravel the molecules involved in the cross-talk between the gamete and its companion cumulus cells during the GV-to-MII transition and to further improve the protocols of antral oocytes maturation in animal studies and human clinical applications
"PULS." - Ein Blog als Online-Magazin für Medizinstudierende der Goethe-Universität Frankfurt
No full textIm Herbst 2009 forderten Studierende im Rahmen landesweiter Proteste auch am Fachbereich Medizin/Zahnmedizin der Goethe-Universität Frankfurt mehr Transparenz und Kommunikation zu Angelegenheiten ihres Studiums. Einen innovativen Lösungsansatz, um diesen Forderungen nachzukommen, bietet eines der Web 2.0 Werkzeuge: ein auf einer Blog-Software basierendes Online-Magazin für Studierende und andere Mitglieder des Fachbereichs.
Das öffentlich zugängliche Online-Magazin "PULS." (https://newsmagazin.puls.med.uni-frankfurt.de/wp/) wird mit einer freien Blog-Software (wordpress Version 3.1.3.) realisiert und von einer Online-Redakteurin konzipiert und geschrieben. Die Beiträge entstehen nach eigenen Recherchen sowie aus Anregungen und Gesprächen mit verschiedenen Personengruppen des Fachbereichs. Die datenschutzkonforme Auswertung der Zugriffe erfolgt über eine open-source Webanalyse-Software (Piwik). Zusätzlich werden jährlich mit dem Online-Umfrage-Tool Survey Monkey die Nutzer anonym befragt.
"PULS." ist seit dem 14.02.2010 ununterbrochen online und hat seitdem 806 Beiträge (Stand: 27.11.2012) publiziert und wird von ca. 2400 Besuchern monatlich gelesen. Das Themenspektrum ist zentriert auf die Anliegen der Frankfurter Medizin- und Zahnmedizinstudierenden. Die enge Zusammenarbeit mit verschiedenen Gruppierungen des Fachbereichs – Dekanat, Studierende und Lehrende – garantiert darüber hinaus ein fachbereichs-relevantes Themenspektrum. Das Online-Magazin begleitet komplexe Projekte und Entscheidungen mit Hintergrundinformationen und kommuniziert sie verständlich. Eine jährliche Nutzer-Evaluierung zeigt eine wachsende Leserzahl und eine sehr hohe Zustimmung für das Online-Magazin, seine Inhalte und seinen Stil. Das Web 2.0-Medium "Blog" und seine web-typische Sprache entsprechen dem Medienverhalten der Zielgruppe, d.h. den Studierenden des Fachbereichs Medizin.
"PULS." hat sich als ein geeignetes und strategisches Instrument erwiesen, um größere Transparenz, mehr Kommunikation und letztendlich eine stärkere Identifikation der Studierenden mit ihrem Fachbereich voranzutreiben
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
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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