11th Nanoscience and Nanotechnology Conference (NanoTR-11) Ankara, Turkey. 22 -25 June, 2015
Development of Nano Sized CaP-Silk Fibroin-PCL-PEG-PCL/PCL Based Biphasic Constructs for Guided Bone Regeneration
Sibel Ataol1, Nesrin E. Machin5 , A. Engin Pazarçeviren2, Dilek Keskin1,2,3, Ozgur Duygulu4,Ayşen Tezcaner 1,2,3* Departments of 1Biomedical Eng., 2Engineering Sciences, 3BIOMATEN Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University, Ankara, 06800 Turkey 4 Materials Institute, TUBITAK Marmara Research Center, Kocaeli- Gebze, 41470, Turkey 5 Department of Chemical Engineering and Applied Chemistry, Atılım University, Ankara 06836,Turkey
[email protected] 1. Introduction Guided bone regeneration (GBR) concept has been developed to prevent the formation of non-functional scar tissue layer on the defect site by barrier role [1–3]. We propose a new type of bilayer membrane composite constituted from one phase silk fibroin and nano CaP,and other phase of PCL for GBR. In order to challenge the mechanical stability at the bone defect and inhibit the fibrous tissue formation, one side will be fabricated from a hydrophobic, slowly degrading polycaprolactone (PCL) based membrane, and nano CaP containing electrospun phase on the other side. In order to induce bone regeneration at the defect site, the other side of the membrane is fabricated from gradient hydrophilic phase; electrospun biodegradable silk fibroin/PCL-PEG-PEG and calcium phosphates mimicking bone extracellular matrix. The osteoconductivity of this composite membrane was improved by incorporation of nano sized calcium phosphate synthesized by Flame Spray Pyrolysis as in natural bone tissue. 2. Materials and Methods The layers were prepared with solvent casting and electrospinning method. PCL (10%, w/v) casted on petri glass and dried at room temperature. Firstly, PCL (10%) was spinned on PCL membrane for obtaining continuity of casted film and electrospun layer. SF-PEO (7%, 5:1) and CaP (10% (w/w) of fibroin) were blended and spinned on electrospun PCL.
sintered at 900oC for 2h. This step was conducted to reduce phase impurity. The particles consisted of HA and β-TCP which was confirmed by XRD analysis (Figure 3). The presence of these phases was also examined on absorbance peaks of FTIR (Figure 4).
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Figure 2. TEM image of CaP (Ca/P: 2.19) (a), HRTEM image of CaP and crystalline regions of particles (b)
Figure 3. XRD spectrum of nano CaP (Ca/P: 2.19)
Figure 1 Electrospinning of Fibroin-CaP and PCL on PCL membrane to prepare biphasic membranes X-ray diffraction (XRD), scanning electron microscopyelectron dispersive spectroscopy (SEM-EDS), DLS, high resolution transmission electron microscopy (HRTEM), FTIR techniques and contact angle measurements were used for compositional, structural and morphological characterization of the CaP nanoparticles incorporated fibroin and PCL based bilayer. 3. Results &Discussion The average sizes of calcium phosphate particles were measured as 180 nm by DLS analysis and 23 nm with TEM analysis [4] (Figure 2). These particles were
Figure 4 FTIR spectrum of nano CaP (Ca/P: 2.19) The thickness of PCL membrane casted on glass was measured as 150 µm. The electrospinning of other layers will be performed and analyzed. 4. References [1] Needleman IG et al,. C. Database Syst Rev (2006) [2] Oliveira AL et al. Acta Biomater;8:1530–42, (2012). [3] Hämmerle CHF. et al., J Clin Periodontol;29 Suppl 3:226–31, (2002).
[4] Ataol S, et al., J Nanoparticle Res 17:95. (2015).
Associazione Italiana di Tribologia (http://www.aitrib.it/)
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