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EKREN, NAZMİ

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Author: OKTAR, FAİK NÜZHET × Subject: 3D printing ×

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Now showing 1 - 3 of 3
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    Production of 3D-Printed Tympanic Membrane Scaffolds as a Tissue Engineering Application
    (Springer, 2020) ŞAHİN, ALİ; Ilhan E., Ulag S., Sahin A., Ekren N., Kilic O., Oktar F.N., Gunduz O.
    In recent years, scaffolds produced in 3D printing technology have become more widespread tool due to providing more advantages than traditional methods in tissue engineering applications. In this research, it was aimed to produce patches for the treatment of tympanic membrane perforations which caused significant hearing loss by using 3D printing method. Polylactic acid (PLA) scaffolds with Chitosan (CS) added in various ratios were prepared for artificial eardrum patches. Different amounts of CS added to PLA to obtain more biocompatible scaffolds. The created patches were designed by mimicking the thickness of the natural tympanic membrane thanks to the precision provided by the 3D printed method. The produced scaffolds were analyzed separately for physical, chemical, morphological, mechanical and biocompatibility properties. Human adipose tissue-derived mesenchymal stem cells (hAD-MSCs) were used for cell culture study to analyze the biocompatibility properties. 15 wt% PLA was chosen as the control group. Scaffold containing 3 wt% CS demonstrated significantly superior and favorable features in printing quality. The study continued with these two scaffolds (15PLA and 15PLA/3CS). This study showed that PLA and PLA/CS 3D printed scaffolds are a potential application for repairing tympanic membrane perforation. © Springer Nature Switzerland AG 2020.
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    3D printed artificial cornea for corneal stromal transplantation
    (PERGAMON-ELSEVIER SCIENCE LTD, 2020-06) ŞAHİN, ALİ; Ulag, Songul; Ilhan, Elif; Sahin, Ali; Yilmaz, Betul Karademir; Kalaskar, Deepak M.; Ekren, Nazmi; Kilic, Osman; Oktar, Faik Nuzhet; Gunduz, Oguzhan
    The aim of this study is to understand the optical, biocompatible, and mechanical properties of chitosan (CS) and polyvinyl-alcohol (PVA) based corneal stroma constructs using 3D printing process. Corneal stroma is tested for biocompatibility with human adipose tissue-derived mesenchymal stem cells (hASCs). Physico-chemical and chemical characterization of the construct was performed using scanning electron microscopy (SEM), fourier transforms infrared spectroscopy (FTIR). Optical transmittance was analyzed using UV-Spectrophotometer. Results showed fabricated constructs have required shape and size. SEM images showed construct has thickness of 400 mu m. The FTIR spectra demonstrated the presence of various predicted peaks. The swelling and degradation studies of 13%(wt)PVA and 13%(wt)PVA/(1, 3, 5)%(wt)CS showed to have high swelling ratios of 7 days and degradation times of 30 days, respectively. The light transmittance values of the fabricated cornea constructs decreased with CS addition slightly. Tensile strength values decreased with increasing CS ratio, but we found to support intraocular pressure (IOP) which ranges from 12 to 22 mm-Hg. Preliminary biostability studies showed that composite constructs were compatible with hASCs even after 30 days' of degradation, showing potential for these cells to be differentiated to stroma layer in future. This study has implications for the rapid and custom fabrication of various cornea constructs for clinical applications.
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    3D bio-printing of levan/polycaprolactone/gelatin blends for bone tissue engineering: Characterization of the cellular behavior
    (PERGAMON-ELSEVIER SCIENCE LTD, 2019) İNAN, AHMET TALAT; Duymaz, Busra Tugce; Erdiler, Fatma Betul; Alan, Tugba; Aydogdu, Mehmet Onur; Inan, Ahmet Talat; Ekren, Nazmi; Uzun, Muhammet; Sahin, Yesim Muge; Bulus, Erdi; Oktar, Faik Nuzhet; Selvi, Sinem Selvin; ToksoyOner, Ebru; Kilic, Osman; Bostan, Muge Sennaroglu; Eroglu, Mehmet Sayip; Gunduz, Oguzhan
    Poly(epsilon-caprolactone) (PCL), gelatin (GT) and different concentrations of low molecular weight Halomonas levan (HLh) were combined and examined to develop physical networks serving as tissue scaffolds to promote cell adhesion for biocompatibility. Three-dimensional bioprinting technique (3D bioprinting) was employed during manufacturing the test samples and their comprehensive characterization was performed to investigate the physicochemical properties and biocompatibility. Physical properties of the printing materials such as viscosity, surface tension, and density were measured to determine optimal parameters for 3D bioprinting. The scanning electron microscope (SEM) was used to observe the morphological structure of scaffolds. Fourier-Transform Infrared Spectroscopy (FT-IR) and differential scanning calorimetry (DSC) were used to identify the interactions between the components. In-vitro cell culture assays using standard human osteoblast (Hob) cells showed increased biocompatibility of the printing materials with increasing HLh content. Thus, the formulations including the HLh are expected to be a good candidate for the production of 3D printed materials.