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ŞAHİN, ALİ

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ŞAHİN

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ALİ

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Now showing 1 - 3 of 3
  • Publication
    Fabrication of tissue-engineered tympanic membrane patches using 3D-Printing technology
    (ELSEVIER, 2021) ŞAHİN, ALİ; Ilhan, Elif; Ulag, Songul; Sahin, Ali; Yilmaz, Betul Karademir; Ekren, Nazmi; Kilic, Osman; Sengor, Mustafa; Kalaskar, Deepak M.; Oktar, Faik Nuzhet; Gunduz, Oguzhan
    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) and Sodium Alginate(SA) added in various ratios were prepared for artificial eardrum patches. Different amounts of chitosan and sodium alginate added to PLA increased the biocompatibility of the produced 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 chemical, morphological, mechanical and biocompatibility properties. Scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) spectroscopy was performed to observe the surface morphology and chemical structure of the scaffolds. Mechanical, thermal and physical properties, swelling and degradation behaviors were examined to fully analyze whole characteristic features of the samples. Cell culture study was also performed to demonstrate the biocompatibility properties of the fabricated scaffolds with human adipose tissue-derived mesenchymal stem cells (hAD-MSCs). 15 wt % PLA was selected as the control group and among all concentrations of CS and SA, groups containing 3 wt% CS and 3 wt% SA showed significantly superior and favorable features in printing quality. The research continued with these two scaffolds (3 wt% CS, and 3 wt% SA), which showed improved print quality when added to PLA. Overall, these results show that PLA/CS and PLA/SA 3D printed artificial patches have the potential to tissue engineering solutions to repair tympanic membrane perforation for people with hearing loss.
  • Publication
    Effect of electric stimulus on human adipose-derived mesenchymal stem cells cultured in 3D-printed scaffolds
    (WILEY, 2021) ŞAHİN, ALİ; Bedir, Tuba; Ulag, Songul; Aydogan, Kivanc; Sahin, Ali; Yilmaz, Betul Karademir; Guvenc, Yahya; Bozlar, Michael; Ustundag, Cem Bulent; Gunduz, Oguzhan
    Electrical stimulation has shown great potential for nerve regeneration processes. This makes it attractive to use electrically active materials in the neural scaffold. In this paper, bismuth ferrite (BFO) nanoparticles were synthesized via co-precipitation method and incorporated to 10 wt% polylactic acid (PLA) in chloroform to obtain 3D-printed PLA/BFO biocomposites. The crystallinity of BFO nanoparticles was confirmed by XRD, and we studied its chemical structure with FTIR, as well as the mechanical properties of the 3D-printed composites. in vitro studies show that 3D-printed scaffolds have no cytotoxicity and support the proliferation of human adipose-derived mesenchymal stem cells (hADMSCs). Furthermore, 3D scaffolds embedded with BFO shows the highest cell viability relative to pristine PLA and BFO-lined PLA scaffolds. A 48 hours electrical stimulation on the hADMSC cultured inside the 3D-printed BFO-lined PLA scaffolds indicates that stimulated cells are aligned toward the BFO line. These results could indicate the potential of BFO for directing cells toward damaged tissues.
  • PublicationOpen Access
    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.