Person: ŞAHİN, ALİ
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ŞAHİN
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ALİ
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Publication Open Access Controlled delivery of amoxicillin and rifampicin by three-dimensional polyvinyl alcohol/bismuth ferrite scaffolds(2023-05-01) ULAĞ, SONGÜL; ŞAHİN, ALİ; Ilgar S., ULAĞ S., ŞAHİN A., GÜNDÜZ O., Ustundag C. B.Skin is a protective barrier that can protect against environmental influences and renew itself. However, in some cases, this regenerative property is lost, and this causes delays in wound healing. Wound healing is a complex and long-lasting phase. Any bacterial infection during the wound healing process delays wound healing. The therapeutic efficacy can be increased by using nanocarrier drug delivery systems to the target tissue with modern wound dressings. Controlled nano drug delivery systems increase the therapeutic efficacy in the treatment of diseases and provide a faster recovery process. In this study, amoxicillin (AMX) and rifampicin (RIF) were loaded into the bismuth ferrite (BFO) particles which were synthesized with the co-precipitation method. Then, these drug-loaded BFO particles (0.075 %) were added separately to 13 % polyvinyl alcohol (PVA) solution and the solutions were printed three-dimensionally to obtain three dimensional scaffolds. With these designed scaffolds, it is aimed to reduce the risk of inflammation in wound tissues and increase therapeutic efficacy with controlled release. The SEM images proved that homogeneous pore distributions could be achieved with these combinations. The tensile test results showed that drug-loaded BFO addition increased the mechanical strength of the 13 % PVA scaffold. The biocompatibility test results demonstrated that the highest viability values of the human adipose tissue-derived mesenchymal stem cells were obtained for AMX-added 13 % PVA scaffolds.Publication Open Access 3D-Printed PCL scaffolds combined with juglone for skin tissue engineering(2022-08-30) ŞAHİN, ALİ; Ayran M., Dirican A., Saatcioglu E., Ulag S., Sahin A., Aksu B., Croitoru A., Ficai D., Gunduz O., Ficai A.; Tıp FakültesiSkin diseases are commonly treated with antihistamines, antibiotics, laser therapy, topical medications, local vitamins, or steroids. Since conventional treatments for wound healing (skin allografts, amnion, xenografts, etc.) have disadvantages such as antigenicity of the donor tissue, risk of infection, or lack of basement membrane, skin tissue engineering has become a popular new approach. The current study presents the design and fabrication of a new wound-dressing material by the addition of Juglone (5-hydroxy-1,4-naphthoquinone) to a 25% Polycaprolactone (PCL) scaffold. Juglone (J) is a significant allelochemical found in walnut trees and, in this study is used as a bioactive material. The effects of different amounts of J (1.25, 2.5, 5, 7.5, and 10 mg) on the biocompatibility, mechanical, chemical, thermal, morphological, and antimicrobial properties of the 3D-printed 25% PCL scaffolds were investigated. The addition of J increased the pore diameter of the 25% PCL scaffold. The maximum pore size (290.72 ± 14 µm) was observed for the highest amount of J (10 mg). The biocompatibility tests on the scaffolds demonstrated biocompatible behavior from the first day of incubation, the 25% PCL/7.5 J scaffold having the highest viability value (118%) among all of the J-loaded scaffolds. Drug release of J into phosphate buffered saline (PBS) at pH 7.4 showed that J was completely released from all 25% PCL/J scaffolds within 7 days of incubationPublication 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 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 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.