Person: ŞAHİN, ALİ
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ŞAHİN
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ALİ
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Publication Open Access Levodopa-Loaded 3D-Printed Poly (Lactic) Acid/Chitosan Neural Tissue Scaffold as a Promising Drug Delivery System for the Treatment of Parkinson's Disease(MDPI, 2021-11-13) ŞAHİN, ALİ; Saylam, Ezgi; Akkaya, Yigit; Ilhan, Elif; Cesur, Sumeyye; Guler, Ece; Sahin, Ali; Cam, Muhammmet Emin; Ekren, Nazmi; Oktar, Faik Nuzhet; Gunduz, Oguzhan; Ficai, Denisa; Ficai, AntonParkinson's disease, the second most common neurodegenerative disease in the world, develops due to decreased dopamine levels in the basal ganglia. Levodopa, a dopamine precursor used in the treatment of Parkinson's disease, can be used as a drug delivery system. This study presents an approach to the use of 3D-printed levodopa-loaded neural tissue scaffolds produced with polylactic acid (PLA) and chitosan (CS) for the treatment of Parkinson's disease. Surface morphology and pore sizes were examined by scanning electron microscopy (SEM). Average pore sizes of 100-200 mu m were found to be ideal for tissue engineering scaffolds, allowing cell penetration but not drastically altering the mechanical properties. It was observed that the swelling and weight loss behaviors of the scaffolds increased after the addition of CS to the PLA. Levodopa was released from the 3D-printed scaffolds in a controlled manner for 14 days, according to a Fickian diffusion mechanism. Mesenchymal stem cells (hAD-MSCs) derived from human adipose tissue were used in MTT analysis, fluorescence microscopy and SEM studies and confirmed adequate biocompatibility. Overall, the obtained results show that PLA/CS 3D-printed scaffolds have an alternative use for the levodopa delivery system for Parkinson's disease in neural tissue engineering applications.Publication Metadata only Design and fabrication of electrospun polycaprolactone/chitosan scaffolds for ligament regeneration(PERGAMON-ELSEVIER SCIENCE LTD, 2021) İNAN, AHMET TALAT; Saatcioglu, Elif; Ulag, Songul; Sahin, Ali; Yilmaz, Betul Karademir; Ekren, Nazmi; Inan, Ahmet Talat; Palaci, Yuksel; Ustundag, Cem Bulent; Gunduz, OguzhanTendon and ligament impairments are among the most familiar injuries of the knee with acute or chronic pain conditions. The defects of anterior cruciate ligament (ACL) stay a known clinical problem. In the present study, the electrospinning method was used to fabricate 10wt.%PCL/(1, 3, 5)wt.%Chitosan (CS) appropriate and biocompatible scaffolds with a similar connective ligament geometry and structure. 10wt.%PCL/3wt.%CS demonstrated higher tensile strength value (0.58854 MPa) than other scaffolds in the tensile test. Moreover, 10wt.%PCL/3wt.%CS scaffolds had high mesenchymal stem cells (MSCs) viability value for all incubation periods. Swelling and degradation behaviours of the ligament-like scaffolds were examined in vitro for 15 days. Results reported that the highest swelling ratio was observed with CS addition for 10wt.%PCL/5wt.%CS scaffolds which value nearly reached to the 270% ratio. Scanning electron microscope proved the geometry of the scaffolds, which were suitable for ligament-like tissue. Attachment of MSCs on the scaffolds proved the network-like structure of the cells on the scaffolds.Publication Metadata only Investigation of 3D-Printed Polycaprolactone-/Polyvinylpyrrolidone-Based Constructs(SAGE PUBLICATIONS INC) ŞAHİN, ALİ; Izgordu, Muhammet Sefa; Uzgur, Evren Isa; Ulag, Songul; Sahin, Ali; Yilmaz, Betul Karademir; Kilic, Beyhan; Ekren, Nazmi; Oktar, Faik Nuzhet; Gunduz, OguzhanThe aim of this study is to evaluate the mechanical and biological performance of cartilage-like constructs produced by 3D printing. During the investigation, poly(epsilon-caprolactone) (PCL) and polyvinylpyrrolidone (PVP) were used as a matrix polymer and low-molecular-weight chitosan (CS), hyaluronic acid (HA), and alginic acid sodium salt (SA) were integrated separately with the polymer matrix to fabricate the constructs. Thermal, mechanical, morphology, and chemical properties and swelling, degradation, and biocompatibility behaviors were evaluated in detail. With the addition of 3 fillers, the melting temperature of the matrix increased with the addition of fillers, and PCL/3wt.%PVP/1wt.%HA had the highest melting temperature value. Mechanical characterization results demonstrated that the printed PCL/3wt.%PVP/1wt.%CS displayed the highest compressive strength of around 9.51 MPa. The compressive strength difference between the PCL/3wt.%PVP and PCL/3wt.%PVP/1wt.%CS was 5.38 MPa. Biocompatibility properties of the constructs were tested by mitochondrial dehydrogenase activity, and in vitro studies showed that the PCL/3wt.%PVP/1wt.%HA composite construct had more cell viability than the other constructs by making use of the mesenchymal stem cell line.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 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.