Back to overview

Poster Presentation

Drug loaded silicon based soft contact lenses: effect of terminal sterilization methods on their performance

Part of:
- Poster Presentation The European user access program nanoscience foundries and fine analysis (NFFA) 0 Dr.-Ing. Thomas F. Keller
- Poster Presentation Sarcoma osteogenic-like Saos-2 cells on the silica nanofibres coated with nanodiamond 1 Marie Steinerova
- Poster Presentation Sputtered, micro structured freestanding FeMn foils as biodegradable material 0 Till Jurgeleit
- Poster Presentation Exploring the effects of organic components on the degradation of magnesium in vitro under physiological conditions 1 Ph.D. Ruiqing Hou
- Poster Presentation Influence of laser treatment on the corrosion behavior of Mg-1Zn-1Ca and Mg-3Zn-0.3Ca alloys 1 Ph.D. Nuria Pulido González
- Poster Presentation PLA based CaCO3 composite fibers for textile scaffolds in hard tissue regeneration 1 Dr.-Ing. Claudia Hinüber
- Poster Presentation Functionalization of polymer fibers with heparan sulfate as a representative of the extracellular matrix 1 Inga Wille
- Poster Presentation Development and Characterization of Hybrid Hydrogel Based on Oxidized Alginate and Keratin for Tissue Engineering Applications 0 Supachai Reakasame
- Poster Presentation Nir Laser-responsive Folate-targeted Gold Nanorods As Efficient theranostic tool for Osteosarcoma Treatment 1 Ph.D. Nicol? Mauro
- Poster Presentation Mechanical properties of recent CAD/CAM polymer materials 1 Sebastian Spintzyk
- Poster Presentation Multilayers of Nanoparticles with Alginate, Chondroitin sulfate and Hyaluronic acid for graded implants 1 Steffen Sydow
- Poster Presentation Design of drug eluting ophthalmic lenses through a multi-layer approach 1 Dr. Ana Topete
- Poster Presentation Drug loaded silicon based soft contact lenses: effect of terminal sterilization methods on their performance 1 Andreia Sofia Oliveira
- Poster Presentation Investigating the compressibility of spray dried alumina-zirconia granules for use in orthopaedics - an easy to use and fast method 1 Dr. Ranko Adjiski
- Poster Presentation Biochemical modification of extruded protein nanofibers 1 Karsten Stapelfeldt
- Poster Presentation Microfibers and Nanoparticles with Controlled Dimensions of a Hyaluronic Acid Derivative 1 Ph.D. Calogero Fiorica
- Poster Presentation Modeling the Viscosity of Silicone Rubber During High-Speed Infrared Curing 1 Jan Stieghorst
- Poster Presentation Effect of the pH of bleaching H2O2 solutions in the enamel morphology, hardness and color 1 Dr. Ana Topete
- Poster Presentation New crosslinking diluents for dental materials 1 Prof. Dr. Norbert Moszner
- Poster Presentation Microstructure and Properties of Plasma Sprayed Bioactive Glass Ceramics Coatings 1 Annamária Dobrádi
- Poster Presentation Impact of chloride ions on apatite mineralisation on Bioglass® 45S5 0 Juliane Brandt-Slowik
- Poster Presentation In vivo performance of polymeric photodynamic active biomaterials for periodontal regeneration 1 Dr. Stefan Kranz
- Poster Presentation Adjusted material-cell interaction using engineered spider silk proteins 1 Vanessa Trossmann
- Poster Presentation Cellular interactions with extruded protein nanofibers 1 Naiana Suter
- Poster Presentation Antimicrobial efficacy of strontium and zinc glasses and glass ionomer cements against clinically relevant bacteria 0 Hawshan Mustafa
- Poster Presentation Mechanical properties of water-soluble polyvinyl alcohol parts fabricated by fused deposition modelling 1 Jochen Kuttig
- Poster Presentation Corrosion behavior of dental CoCr alloys made by different digital workflow processes compared to cast CoCr alloys 0 Christine Schille
- Poster Presentation Mechanical properties of biocompatible polymer-based resin for dental applications fabricated by stereolithography 1 Phan Hai-Binh Bui

Session P.2: Poster Session 2
Belongs to:
Topic P: Postersession

The effects of sterilization methods on the intrinsic properties of drug delivery systems (DDS) remains understudied, which ends up delaying the development of new and more effective therapeutic devices. This fact becomes even more critical when considering hydrogel-based DDS, since the presence of water in the structure can lead to alterations in the materials.

In this work, a comparative evaluation of the effects of two terminal sterilization methods, steam heat and gamma-irradiation, in a drug loaded silicon-based hydrogel intended for soft contact lens, was carried out. Two drugs, commonly used for the treatment of ocular diseases, levofloxacin and timolol maleate, were loaded in the material by soaking. A complete characterization was performed before and after the sterilization procedures, as follows: swelling capacity was determined by water uptake studies, transparency was accessed by UV-Vis spectroscopy, surface topography/morphology by scanning electron microscopy (SEM) and mechanical properties through tensile tests. The drug released was quantified by high performance liquid chromatography (HPLC).

For unsterilized drug loaded samples, differences in swelling behavior were observed and, in all cases, the material became more rigid after loading, which can indicate interactions between the drugs and the polymeric matrix. Steam heat led to smoother surfaces and an apparent decrease in surface porosity. It was also observed a significant decrease of the amount of drug released. Gamma-irradiation led to darkening of the drug loaded samples and to the formation of degradation products. Both steam heat and gamma-irradiation led to a significant increase of Young modulus along with a significant decrease of tension at break, elongation at break and toughness.

Our findings offer important insights that can be a useful contribution to the development of new DDS based on silicon-hydrogel contact lenses.


Andreia Sofia Oliveira
Universidade de Lisboa
Additional Authors:
  • Raquel Galante
    Universidade de São Paulo and Universidade de Lisboa
  • Dr. Daniela Ghisleni
    Universidade de São Paulo
  • Dr. Marina Braga
    Universidade de São Paulo
  • Prof. Dr. Terezinha J. A. Pinto
    Universidade de São Paulo
  • Prof. Dr. Rogério Colaço
    Universidade de Lisboa
  • Prof. Dr. Ana Paula Serro
    Universidade de Lisboa and Egas Moniz - Cooperativa de Ensino Superior