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 The effect of polycaprolactone/graphene oxide electrospun scaffolds on the neurogenic behavior of adipose stem cells(Elsevier Ltd, 2022) ŞAHİN, ALİ; Pinar E., Sahin A., Unal S., Gunduz O., Harman F., Kaptanoglu E.Stem cell destiny can be controlled with scaffold biomaterials in tissue engineering and regenerative medicine. This study aimed to investigate the neuronal differentiation potential of human adipose tissue-derived mesenchymal stem cells in graphene nanofiber matrix in vitro. Stem cell isolation was performed from adipose tissue taken from human by mechanical and enzymatic methods. The differentiation potential was examined after incubation of adipose stem cells in normal medium and neural differentiation medium, on graphene oxide (GO) and polycaprolactone (PCL) composite scaffolds produced by electrospinning technique. In vitro studies indicated that the presence of GO in PCL scaffold increases an effect on cell attachment, proliferation, infiltration into the scaffold, and neuronal differentiation. Also, unlike subcutaneous tissue, it has been shown immunohistochemically that mesenchymal stem cells derived from epidural adipose tissue tend to differentiate into oligodendrocytes. © 2022 Elsevier LtdPublication 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 Open Access Production and characterization of PLA/HA/GO nanocomposite scaffold(2022-08-12) ŞAHİN, ALİ; GÜNDÜZ, OĞUZHAN; Oktay B., Ahlatcıoğlu Özerol E., Şahin A., Gunduz O., Ustundag C. B.© 2022 Wiley-VCH GmbH.Polylactic acid (PLA) composite nanofibers combined with hydroxyapatite (HA) and graphene oxide (GO) nanoparticles were produced by electrospinning to create excellent biodegradable and durable scaffolds to be used in tissue engineering. The properties of the pure PLA, PLA/HA, PLA/GO, and PLA/HA/GO nanocomposite scaffolds were analyzed in chemical, morphological, mechanical, and biocompatibility. Morphology and composition were investigated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. To predict the cytocompatibility of these scaffolds, HFF-1 cells were cultured and the respective cell adhesion and proliferation were investigated by fluorescence microscopy, SEM, and MTT assay. FTIR results showed the successful synthesis of HA and GO nanoparticles. SEM images showed that the PLA/HA/GO scaffold is ideal for cell attachment and proliferation in tissue regeneration. Mechanical test results showed that the tensile strength and elastic modulus of PLA nanofibers could be increased by adding 0,8 wt % HA and 0,4 wt % GO. The PLA/HA/GO scaffold exhibited the highest tensile strength of other scaffolds. MTT assay revealed that the PLA/HA/GO scaffold showed significantly high biocompatibility with 105 % cell viability. Therefore, PLA/HA/GO scaffold with 0,8 wt %HA and 0,4 wt %GO possessing high tensile strength as well as good cell proliferation is an excellent and versatile biomaterial for tissue engineering applications.Publication Open Access Dual spinneret electrospun polyurethane/pva-gelatin nanofibrous scaffolds containing cinnamon essential oil and nanoceria for chronic diabetic wound healing: preparation, physicochemical characterization and in-vitro evaluation(2022-04-01) ŞAHİN, ALİ; GÜNDÜZ, OĞUZHAN; Hussein M. A. M., Gunduz O., Sahin A., Grinholc M., El-Sherbiny I. M., Megahed M.© 2022 by the authors. Licensee MDPI, Basel, Switzerland.In this study, a dual spinneret electrospinning technique was applied to fabricate a series of polyurethane (PU) and polyvinyl alcohol–gelatin (PVA/Gel) nanofibrous scaffolds. The study aims to enhance the properties of PU/PVA-Gel NFs loaded with a low dose of nanoceria through the incorporation of cinnamon essential oil (CEO). The as-prepared nCeO2 were embedded into the PVA/Gel nanofibrous layer, where the cinnamon essential oil (CEO) was incorporated into the PU nanofibrous layer. The morphology, thermal stability, mechanical properties, and chemical composition of the produced NF mats were investigated by STEM, DSC, and FTIR. The obtained results showed improvement in the mechanical, and thermal stability of the dual-fiber scaffolds by adding CEO along with nanoceria. The cytotoxicity evaluation revealed that the incorporation of CEO to PU/PVA-Gel loaded with a low dose of nanoceria could enhance the cell population compared to using pure PU/PVA-Gel NFs. Moreover, the presence of CEO could inhibit the growth rate of S. aureus more than E. coli. To our knowledge, this is the first time such nanofibrous membranes composed of PU and PVA-Gel have been produced. The first time was to load the nanofibrous membranes with both CEO and nCeO2. The obtained results indicate that the proposed PU/PVA-Gel NFs represent promising platforms with CEO and nCeO2 for effectively managing diabetic wounds.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 Open Access Fabrication of electrospun juglans regia (juglone) loaded poly(lactic acid) scaffolds as a potential wound dressing material(2022-05-01) ALTAN, ERAY; ŞAHİN, ALİ; GÜNDÜZ, OĞUZHAN; ULAĞ, SONGÜL; ALTAN E., Karacelebi Y., Saatcioglu E., ULAĞ S., ŞAHİN A., AKSU M. B., Croitoru A., Codrea C. I., Ficai D., GÜNDÜZ O., et al.Juglone (5-hydroxy-1,4-naphthoquinone) (J) is a naphthoquinone structured allelochemical that is mostly found in the roots, leaves, nut-hulls, bark, and wood of walnut (Juglans regia). In this study, the biocompatibility, mechanical, thermal, chemical, morphological, and antimicrobial properties of the poly(lactic acid) (PLA) (w/v)/J (10, 20, 30 mg) electrospun scaffolds were investigated. Based on the results of the study, it was shown that juglone addition increased the antimicrobial properties of the scaffolds against the Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), compared to the neat PLA film after 24 h of contact time. According to the tensile test results, the addition of J made the scaffolds more flexible but decreased the mechanical strength. The cytotoxicity properties of the J-added scaffolds demonstrated a toxic behavior on the first day of incubation. However, with an increase in the J ratio, the fibroblast cell metabolic activity increased for all incubation periods.Publication Open Access Propolis-Based Nanofiber Patches to Repair Corneal Microbial Keratitis(MDPI, 2021-04-28) ŞAHİN, ALİ; Ulag, Songul; Ilhan, Elif; Demirhan, Ramazan; Sahin, Ali; Yilmaz, Betul Karademir; Aksu, Burak; Sengor, Mustafa; Ficai, Denisa; Titu, Aurel Mihail; Ficai, Anton; Gunduz, OguzhanIn this research, polyvinyl-alcohol (PVA)/gelatin (GEL)/propolis (Ps) biocompatible nanofiber patches were fabricated via electrospinning technique. The controlled release of Propolis, surface wettability behaviors, antimicrobial activities against the S. aureus and P. aeruginosa, and biocompatibility properties with the mesenchymal stem cells (MSCs) were investigated in detail. By adding 0.5, 1, and 3 wt.% GEL into the 13 wt.% PVA, the morphological and mechanical results suggested that 13 wt.% PVA/0.5 wt.% GEL patch can be an ideal matrix for 3 and 5 wt.% propolis addition. Morphological results revealed that the diameters of the electrospun nanofiber patches were increased with GEL (from 290 nm to 400 nm) and Ps addition and crosslinking process cause the formation of thicker nanofibers. The tensile strength and elongation at break enhancement were also determined for 13 wt.% PVA/0.5 wt.% GEL/3 wt.% Ps patch. Propolis was released quickly in the first hour and arrived at a plateau. Cell culture and contact angle results confirmed that the 3 wt.% addition of propolis reinforced mesenchymal stem cell proliferation and wettability properties of the patches. The antimicrobial activity demonstrated that propolis loaded patches had antibacterial activity against the S. aureus, but for P. aeruginosa, more studies should be performed.Publication Open Access Synthesis and cytotoxicity analysis of porous beta-TCP/starch bioceramics(2022-04-01) ŞAHİN, ALİ; GÜNDÜZ, OĞUZHAN; Turan Y., Kalkandelen C., PALACI Y., ŞAHİN A., Gökçe H., GÜNDÜZ O., Ben-Nissan B.The production of porous ceramics for biomedical applications is widely available in the Ceramics industry. In bioceramic applications, interconnected pores are pertinent to increase osteoconductivity and cell proliferation. However, an increase in pore size and the pore amount decrease the mechanical properties. For this reason, pore properties must be precisely controlled. In this study, the effect of a natural pore-forming agent, corn starch addition, and sintering conditions on mechanical properties and biocompatibility was investigated. During mixing, four different starch amounts (1, 3, 5, and 10 wt%) were added to pure beta-tricalcium phosphate (beta-TCP) ceramic powders and pressed. Pressed pellets were sintered at 1000, 1100, 1200, and 1300 degrees C. A scanning electron microscope (SEM) is used to investigate microstructure, texture, pore size, and cell adhesion. The mechanical properties of the beta-TCP ceramic parts were further characterized by measuring the density and compressive strength. Cytotoxicity tests were carried out with MTT assays. The optimum mechanical properties were obtained at 1100 degrees C sintered biocomposites. Although starch starts to burn around 410 degrees C and analytical results show no presence of starch after the sintering process, biocomposites initially containing 10% starch showed improved cell proliferation. However, a reduction of 59% in compressive strength and a 16% reduction in the density were also recorded. It was observed that 10 wt% starch addition increases cell proliferation by 10% in sintered beta-TCP samples. Starch powder additions can be used to increase the cell viability of the material by facilitating the creation of pores, as a low-cost pore-forming agent for porous bone graft and non-load-bearing material in both orthopaedics and maxillofacial applications.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.