Medical implant use is associated with a risk of infection caused by bacteria on their surface. Implants with a surface that has both bone growth-promoting properties and antibacterial properties are of interest in orthopedics. In the current study, we fabricated a bioactive coating of hydroxyapatite nanoparticles on polyether ether ketone (PEEK) using the sonocoating method. The sonocoating method creates a layer by immersing the object in a suspension of nanoparticles in water and applying a high-power ultrasound. We show that the simple layer fabrication method results in a well-adhering layer with a thickness of 219 nm to 764 nm. Dropping cefuroxime sodium salt (Cef) antibiotic on the coated substrate creates a layer with a drug release effect and antibacterial activity against Staphylococcus aureus. We achieved a concentration of up to 1 mg of drug per cm2 of the coated substrate. In drug release tests, an initial burst was observed within 24 h, accompanied by a linear stable release effect. The drug-loaded implants exhibited sufficient activity against S. aureus for 24 and 168 h. Thus, the simple method we present here produces a biocompatible coating that can be soaked with antibiotics for antibacterial properties and can be used for a range of medical implants.
Event Abstract Back to Event Development of drug-releasing shape-memory polyurethane/hydroxyapatite composites - smart biomaterial for bone tissue implants Monika Bil1, Marcin Heljak1 and Wojciech Swieszkowski1 1 Warsaw University and Technology, Faculty of Materials Science and Engineering, Poland Introduction: Shape-memory polymers (SMPs) are mechanically active or smart materials, which can be deformed and fixed in a temporary shape and are able to return to their original, permanent shape when exposed to a suitable external stimulus. The unique attributes of shape memory effect in conjunction with biodegradability and drug delivery present enormous opportunities for the design of next generation, resorbable less invasive self-fitting medical implants, tissue scaffolds and medical devices[1]-[3]. The ultimate goal of the study is to develop self - deploying drug delivery system for bone tissue regeneration utilizing thermoplastic SMPs which could self-fitting to a target tissue defect and ensure a local drug release at the site of administration. Materials and Methods: Hydroxyapatite/polyurethane (HA/PU) composites were synthesized through in-situ polymerization with biodegradable hydroxyl terminated oligomers of polycaprolactone and poly(lactide-co-glycolide), 1,6-hexamethylene diisocyanate as a coupling agent and dibutyltin dilaurate as the catalyst. HA nanoparticles (Merck) and gentamicin sulfate (GS) ( 5% wt.) ultrasonically dispersed in dehydrated tetrahydrofuran (THF) were added to synthesis mixture. Chemical structure of the composites were analysed by Raman spectroscopy. Drug release study were performed in vitro in PBS and analyzed using UV spectrophotometer at a wavelength of 332 nm. Shape memory behavior was analyzed in thermomechanical test by dynamic mechanical analyzer (DMA) in water. The shape recovery ratio Rr and the fixity ratio Rf were calculated based on DMA measurement. The relationship between amounts of HA, drug content and shape memory properties were analyzed. Results and Discussion: A series of thermoplastic nano-HA/PU/GS composite with the content of HA in the range 3, 5 10 wt. % were synthesized. Quantitative assessment of the shape memory performance through thermomechanical shape memory cycles verified that all materials exhibited a shape-fixing ratio Rf from 80% to 85% and shape recovery ratio (Rr 80-100%). The best shape recovery ability Rf -100% in water at 37oC was observed for composite with 3% wt. of HA. The shape recovery ratio decreased slightly with an increment in HA nanoparticles weight fraction, due to formation of agglomerates that could be a hindrance in recovery of the macromolecule structure. In order to evaluate the effect of shape recovery on drug release profile the drug release study were performed for the samples subjected thermomechanical shape memory cycle. The results revealed sustained drug release over two weeks. However, initial burst release increased with increasing of HA weight fraction what could be connected with easier water penetration into polymer matrix through HA nanoparticles polymer matrix interface. Conclusion: We successfully prepared series of thermoplastic PU/HA composites based on biodegradable oligoesters combining controlled drug release and shape memory effect. All the drug-loaded samples have satisfactory shape memory properties with shape recovery within body relevant temperature, and drug release behavior, therefore appear to be potentially useful for biomedical applications. The authors would like to thank the National Centre for Research and Development (Grant no: LIDER/037/673/L-4/12/NCBR/2013) for providing financial support to this projectReferences:[1] W.M. Huang, C.L. Song, Y.Q. Fu et.al. Shaping tissue with shape memory materials Adv.Drug Deliv. Rev. (2012), doi:10.1016/j.addr.2012.06.004[2] Ch. Wishke, A.T. Neffe, S. Steuer et.al., Evaluation of a degradable shape-memory polymer network as matrix for controlled drug release Journal of Controlled Release (2009) 138, 243-250[3] Maria C. Serrano, Guillermo A. Ameer Recent Insights Into the Biomedical Applications of Shape-memory Polymers Macromol. Biosci. 2012, 12, 1156–1171 Keywords: nanocomposite, biomaterial, stimuli-response, targeting delivery Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Environmentally sensitive biomaterials Citation: Bil M, Heljak M and Swieszkowski W (2016). Development of drug-releasing shape-memory polyurethane/hydroxyapatite composites - smart biomaterial for bone tissue implants. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00732 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Monika Bil Marcin Heljak Wojciech Swieszkowski Google Monika Bil Marcin Heljak Wojciech Swieszkowski Google Scholar Monika Bil Marcin Heljak Wojciech Swieszkowski PubMed Monika Bil Marcin Heljak Wojciech Swieszkowski Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.
Plastic materials are one of the significant components of construction materials omnipresent in all areas of the industry and everyday life. One of these plastics is polyethylene terephthalate (PET). Due to its processing properties, with a simultaneous low production cost, PET has been used in many industrial applications, including the production of various types of bottles. Moreover, the high consumption of PET bottles causes the accumulation of large amounts of their waste and necessitates finding an effective way to recycle them. Electrospinning is a well-known non-complicated method for the fabrication of nonwovens from polymers and composites, which can be utilized in many fields due to their outstanding properties. In addition, it might be a promising technique for the recycling of plastic materials. Therefore, in this study, the electrospinning approach for the recycling of two types of PET bottle wastes-bottles made of virgin PET and bottles made of recycled PET (PET bottles) has been utilized, and a comparison of the properties of the obtained materials have been performed. The fibers with diameters of 1.62 ± 0.22, 1.64 ± 0.18, and 1.89 ± 0.19 have been produced from solutions made of virgin PET granulate, PET bottles, and PET bottles made of recycled bottles, respectively. Obtained fibers underwent morphological observation using a scanning electron microscope. Physico-chemical properties using FTIR, gel chromatography, and differential scanning calorimetry have been evaluated, and mechanical properties of obtained mats have been investigated. Cytotoxicity tests using the L929 mouse fibroblast cell line revealed no cytotoxicity for all tested materials.
The effectiveness of multifunctional composites that combine a shape-memory polyurethane (PU) matrix with hydroxyapatite (HA) as a bioactive agent and antibiotics molecules results from a specific composite structure. In this study, structure-function correlations of PU-based composites consisting of 3, 5, and 10 (wt%) of HA and (5 wt%) of gentamicin sulfate (GeS) as a model drug were investigated. The performed analysis revealed that increasing HA content up to 5 wt% enhanced hydrogen-bonding interaction within the soft segments of the PU. Differential-scanning-calorimetry (DSC) analysis confirmed the semi-crystalline structure of the composites. Hydroxyapatite enhanced thermal stability was confirmed by thermogravimetric analysis (TGA), and the water contact angle evaluated hydrophilicity. The shape-recovery coefficient (Rr) measured in water, decreased from 94% for the PU to 86% for the PU/GeS sample and to 88-91% for the PU/HA/GeS composites. These values were positively correlated with hydrogen-bond interactions evaluated using the Fourier-transform-infrared (FTIR) spectroscopy. Additionally, it was found that the shape-recovery process initiates drug release. After shape recovery, the drug concentration in water was 17 μg/mL for the PU/GeS sample and 33-47 μg/mL for the PU HA GeS composites. Antibacterial properties of developed composites were confirmed by the agar-diffusion test against Escherichia coli and Staphylococcus epidermidis.
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