Person: ŞAHİN, ALİ
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ŞAHİN
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ALİ
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Publication Open Access Fabrication of gentamicin sulfate-loaded 3d-printed polyvinyl alcohol/sodium alginate/gelatin-methacryloyl hybrid scaffolds for skin tissue replacement(2023-01-01) ULAĞ, SONGÜL; ŞAHİN, ALİ; AKSU, MEHMET BURAK; GÜNDÜZ, OĞUZHAN; Izgordu M. S., Ayran M., ULAĞ S., Yildirim R., Bulut B., ŞAHİN A., Guncu M. M., AKSU M. B., GÜNDÜZ O.3D-printed scaffolds can better mimic the function of human skin, both biologically and mechanically. Within the scope of this study, the effect of the addition of different amounts (10, 15, 20 mg) of gentamicin sulfate (GS) to a 10 mL solution of natural and synthetic polymers is investigated. Sodium alginate (SA), gelatin-methacryloyl (GelMA), and polyvinyl alcohol (PVA) are chosen as bioactive materials. The surface morphology and pore structures are visualized by scanning electron microscopy (SEM). According to the results, it is observed that the pore sizes of all scaffolds are smaller than 270 µm, the lowest value (130 µm) is obtained in the scaffold loaded with 15 mg GS, and it also has the highest tensile strength value (12.5 ± 7.6 MPa). Similarly, it is observed that the tensile strength (9.7 ± 4.5 MPa) is high in scaffold loaded with 20 mg GS. The biocompatibility test is performed with fibroblast cells, and the results show that the scaffolds are biocompatible with cells. The antibacterial test is carried out against the S.aureous and E. coli and the results indicate that all GS-loaded scaffolds demonstrate antibacterial activity.Publication Metadata only 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.Publication Metadata only 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, OguzhanIn 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 Open Access 3D Printed Polycaprolactone/Gelatin/Bacterial Cellulose/Hydroxyapatite Composite Scaffold for Bone Tissue Engineering(MDPI, 2020-08-29) ŞAHİN, ALİ; Cakmak, Abdullah M.; Unal, Semra; Sahin, Ali; Oktar, Faik N.; Sengor, Mustafa; Ekren, Nazmi; Gunduz, Oguzhan; Kalaskar, Deepak M.Three-dimensional (3D) printing application is a promising method for bone tissue engineering. For enhanced bone tissue regeneration, it is essential to have printable composite materials with appealing properties such as construct porous, mechanical strength, thermal properties, controlled degradation rates, and the presence of bioactive materials. In this study, polycaprolactone (PCL), gelatin (GEL), bacterial cellulose (BC), and different hydroxyapatite (HA) concentrations were used to fabricate a novel PCL/GEL/BC/HA composite scaffold using 3D printing method for bone tissue engineering applications. Pore structure, mechanical, thermal, and chemical analyses were evaluated. 3D scaffolds with an ideal pore size (similar to 300 mu m) for use in bone tissue engineering were generated. The addition of both bacterial cellulose (BC) and hydroxyapatite (HA) into PCL/GEL scaffold increased cell proliferation and attachment. PCL/GEL/BC/HA composite scaffolds provide a potential for bone tissue engineering applications.Publication Open Access Gentamicin-loaded polyvinyl alcohol/whey protein isolate/hydroxyapatite 3D composite scaffolds with drug delivery capability for bone tissue engineering applications(2022-10-05) ŞAHİN, ALİ; GÜNDÜZ, OĞUZHAN; Tut T. A. , Cesur S., Ilhan E., ŞAHİN A., Yildirim O. S. , GÜNDÜZ O.Bone defects caused by diseases such as bone diseases, tumours, and traumas negatively affect the lives of millions of people around the world. Bone tissue engineering offers a new approach to repairing bone defects. Here, a novel bioactive Polyvinyl alcohol (PVA)/ Whey protein isolate (WPI)/ Hydroxyapatite (HA) composite scaffolds with Gentamicin (GEN)-loaded at varying rates were successfully fabricated by 3D printing technology. The strong interaction between PVA, WPI, HA, and GEN were proved with Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). When the scanning electron microscopy (SEM) images of the produced 3D composite scaffolds were evaluated, it can be said that 3D composite scaffolds with the desired porosity and structure for bone tissue engineering applications were obtained. The 3D PVA/WPI/HA/12GEN composite scaffold was fabricated excellently with its 675 μm pore size. Compression tests revealed that the 3D composite scaffold had a compressive strength of 1.28–1.22 MPa and strain of % 12.89–8.70 and thus met the mechanical desirables of human trabecular bone. Moreover, the compressive strength and strain values of the scaffolds were decreased slightly due to adding the GEN drug. According to the Differential scanning calorimetry (DSC) analysis, it was determined that the highly crystalline structure of PVA was disrupted by adding GEN to the composite scaffolds. It was also observed that the addition of GEN to the scaffold did not significantly affect the swelling and degradation behaviour, and the scaffolds degraded by approximately 55% on the 10th day. The scaffolds exhibited a controlled release profile up to 240 and 264 h and were released with the Korsmeyer-Peppas kinetic model according to the highest correlation number. Cell analysis revealed that biocompatible structures were produced, and osteoblasts formed filopodia extensions, resulting in healthy cell attachment. According to these results, 3D GEN-loaded PVA/WPI/HA composite scaffolds may be a promising innovation for bone defect repair in bone tissue engineering applications.Publication Metadata only 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, OguzhanElectrical 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.Publication Open 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, OguzhanThe 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.Publication Metadata only A novel approach to treat the Thiel-Behnke corneal dystrophy using 3D printed honeycomb-shaped polymethylmethacrylate (PMMA)/Vancomycin (VAN) scaffolds(Elsevier B.V., 2021) ŞAHİN, ALİ; Ulag S., Sahin A., Guncu M.M., Aksu B., Ekren N., Sengor M., Kalaskar D.M., Gunduz O.Thiel-Behnke corneal dystrophy, or honeycomb corneal dystrophy, is an autosomal dominant corneal disorder. Tissue engineering can be a novel approach to regenerate this dystrophy. In this study, the honeycomb geometry of the dystrophy mimicked with a 3D printing technology, and 40% PMMA, 40% PMMA/(0.1, 0.5, 2, and 10)% VAN scaffolds were fabricated with honeycomb geometry. As a result of the biocompatibility test with mesenchymal stem cells (MSCs), it can be said that cells on the scaffolds showed high viability and proliferation for all incubation periods. According to the antibacterial activity results, the 40% PMMA/10% VAN showed antibacterial activity against S. aureous. Mechanical results reported that with the addition of VAN into the 40% PMMA, the tensile strength value increased up to 2% VAN amount. The swelling behaviours of the scaffolds were examined in vitro, and found that the swelling rate increased with a high VAN amount. The release of VAN from the scaffolds showed sustained release behaviour, and it took 13 days to be released entirely from the scaffolds. © 2021 Elsevier B.V.