Browsing by Author "Gunduz, Oguzhan"
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Article Citation Count: 63Coaxial and emulsion electrospinning of extracted hyaluronic acid and keratin based nanofibers for wound healing applications(Pergamon-elsevier Science Ltd, 2021) Şaşmazel, Hilal Türkoğlu; Bedir, Tuba; Kalkandelen, Cevriye; Basar, Ahmet Ozan; Sasmazel, Hilal Turkoglu; Ustundag, Cem Bulent; Gunduz, Oguzhan; Metallurgical and Materials EngineeringNovel composites based on poly(epsilon-caprolactone)/polyethylene oxide loaded with hyaluronic acid(HA) and keratin(KR) were produced separately using emulsion and coaxial electrospinning methods. HA and KR were extracted from animal sources, characterized and loaded into coaxial fiber structures as bioactive agents, separately and together. Morphological, chemical, thermal, and mechanical characteristics of the fibers were investigated. According to the SEM results, diameters of smooth and beadless fibers fabricated via emulsion method were at nanoscale (sub-micron) while fibers of coaxial method were at micro scale. Benefitted electrospinning techniques demonstrated that hydrophobic and hydrophilic polymers can be advantageously combined. Core polymer specific FT-IR bands were not visible, their presence was proven with DSC analysis which confirms core-shell morphology of the fibers. In vitro studies exhibited spun mats did not have any cytotoxic effects and the HA and KR incorporated into the fiber structure synergistically increased cell viability and cell proliferation. This study demonstrated that the electrospun fibers containing HA and KR fabricated by both emulsion and coaxial methods can be efficient for wound healing applications.Article Citation Count: 94Development of Satureja cuneifolia-loaded sodium alginate/polyethylene glycol scaffolds produced by 3D-printing technology as a diabetic wound dressing material(Elsevier, 2020) Ilhan, Elif; Cesur, Sumeyye; Guler, Ece; Topal, Fadime; Albayrak, Deniz; Guncu, Mehmet Mucahit; Gunduz, OguzhanAcute wounds are a common health problem, with millions of people affected and decreased granulation tissue formation and vascularization, it is also a big challenge for wound care researchers to promote acute wound healing around the globe. This study aims to produce and characterize Satureja cuneifolia plant extract (SC) blended with sodium alginate (SA) /polyethylene glycol (PEG) scaffolds for the potential treatment of diabetic ulcer. SA/PEG scaffolds were prepared by adding different concentrations (1, 3, and 5 wt%) of PEG to 9 wt% SA. The morphological and chemical composition of the resulting 3D printed composite scaffolds was determined using scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR), respectively. Mechanical and thermal properties, swelling, and degradation behaviours were also investigated. The release kinetics of SC were performed. The antimicrobial analysis was evaluated against Escherichia coli and Staphylococcus aureus strains. 3D printed scaffolds have shown an excellent antibacterial effect, especially against gram-positive bacteria due to the antibacterial SC extract they contain. Furthermore, the cell viability of fibroblast (L929) cells on/within scaffolds were determined by the colourimetric MTT assay. The SA/PEG/SC scaffolds show a great promising potential candidate for diabetic wound healing and against bacterial infections. (c) 2020 Elsevier B.V. All rights reserved.Article Citation Count: 17Development of Amoxicillin-Loaded Electrospun Polyurethane/Chitosan/ β-Tricalcium Phosphate Scaffold for Bone Tissue Regeneration(Ieee-inst Electrical Electronics Engineers inc, 2018) Uzun, Muhammet; Uzun, Muhammet; Ugar, Gaye; Ozcan, Aslihan; Altun, Esra; Oktar, Faik Nuzhet; Gunduz, OguzhanBiocompatible nanocomposite electrospun fibers containing Polyurethane/Chitosan/beta-Tri calcium phosphate with diverse concentrations were designed and produced through the electrospinning process for bone tissue engineering applications. After the production process, density measurement, viscosity, electrical conductivity, and tensile strength measurement tests were carried out as physical analyses of blended solutions. The chemical structural characterization was scrutinized using Fourier transform infrared spectrometer (FTIR), and scanning electron microscopy (SEM) was used to observe the morphological details of developed electrospun scaffolds. Cell viability, attachment, and proliferation were performed using a L929 fibroblast cell line. Based on the physical, SEM, FTIR analysis, and cell culture studies, preferable nanofiber composition was selected for further studies. Amoxicillin (AMX) was loaded to that selected nanofiber composition for examination of the drug release. In comparison with other studies on similar AMX controlled products, higher drug loading and encapsulation efficiencies were obtained. It has been clearly found that the developed nanofiber composites have potential for bone tissue engineering applications.Article Citation Count: 5A drug-eluting nanofibrous hyaluronic acid-keratin mat for diabetic wound dressing(Springernature, 2022) Şaşmazel, Hilal Türkoğlu; Bedir, Tuba; Kalkandelen, Cevriye; Sasmazel, Hilal Turkoglu; Basar, Ahmet Ozan; Chen, Jing; Gunduz, Oguzhan; Metallurgical and Materials EngineeringDiabetes mellitus is a chronic metabolic disease associated with long-term multisystem complications, among which are non-healing diabetic foot ulcers (DFUs). Electrospinning is a sophisticated technique for the preparation of polymeric nanofibers impregnated with drugs for wound healing, burns, and diabetic ulcers. This study describes the fabrication and characterization of a novel drug-eluting dressing made of core-shell structured hyaluronic acid (HA)-keratin (KR)-polyethylene oxide (PEO) and polycaprolactone (PCL) nanofibers to treat diabetic wounds. The core-shell nanofibers produced by the emulsion electrospinning technique provide loading of metformin hydrochloride (MH), HA, and KR in the core of nanofibers, which in return improves the sustained long term release of the drug and prolongs the bioactivity. Morphological and chemical properties of the fibers were examined by SEM, FTIR, and XRD studies. It was observed that the fibers which contain HA and KR showed thin fiber structure, greater swelling capacity, fast degradation and increased cumulative drug release amount than neat emulsion fibers due to the hydrophilic nature of HA and KR. MH showed a sustained release from all fiber samples over 20 days and followed the first-order and Higuchi model kinetics and Fickian diffusion mechanism according to kinetic analysis results. In vitro cell culture studies showed that the developed mats exhibited enhanced biocompatibility performance with HA and KR incorporation. The results show that HA and KR-based emulsion electrospun fiber mats are potentially useful new nanofiber-based biomaterials in their use as drug carriers to treat diabetic wounds.Editorial Citation Count: 0Editorial: Biofabricated materials for tissue engineering(Frontiers Media Sa, 2024) Şaşmazel, Hilal Türkoğlu; Gunduz, Oguzhan; Ramalingam, Murugan; Ulag, Songul; Metallurgical and Materials Engineering[No Abstract Available]Article Citation Count: 4Fucoidan-loaded electrospun Polyvinyl-alcohol/Chitosan nanofibers with enhanced antibacterial activity for skin tissue engineering(Elsevier, 2023) Puigmal, Arnau Cuesta; Ayran, Musa; Ulag, Songul; Altan, Eray; Guncu, Mehmet Mucahit; Aksu, Burak; Gunduz, OguzhanThe polymeric nanofiber may interact and control certain regeneration processes at the molecular level to repair damaged tissues. This research focuses on the development of characterization and antibacterial capabilities of polyvinyl alcohol (PVA)/chitosan (CS) nanofibres containing fucoidan (FUC) for tissue engineering as a skin tissue substitute. A control group consisting of 13% PVA/(0.1)% CS nanofiber was prepared. To confer anti-bacterial properties to the nanofiber, 10, 20, and 30 mg of FUC were incorporated into this control group. The scanning electron microscope (SEM) proved the homogeneous and beadless structures of the nanofibers. The antibacterial activity of the 13% PVA/(0.1)% CS/(10, 20, 30) FUC was tested against the S.aureus and E.coli and the results showed that with FUC addition, the antibacterial activities of the nanofibers increased. The biocompatibility test was performed with a fibroblast cell line for 1, 3, and 7 days of incubation and the results demonstrated that FUC addition enhanced the bioactivity of the 13% PVA/(0.1)% CS nanofibers. In addition, the biocompatibility results showed that 13% PVA/(0.1)% CS/10 FUC had the highest viability value for all incubation periods compared to the others. In addition, the tensile test results showed that; the maximum tensile strength value was observed for 13% PVA/(0.1)% CS/10 FUC nanofibers.Article Citation Count: 1Physico-chemical characterization and in vitro biological study of manganese doped β-tricalcium phosphate-based ceramics for bone regeneration applications(Springer, 2023) Şaşmazel, Hilal Türkoğlu; Daglilar, Sibel; Kalkandelen, Cevriye; Balescu, Liliana-Marinela; Sasmazel, Hilal Turkoglu; Pasuk, Iuliana; Gunduz, Oguzhan; Metallurgical and Materials EngineeringThis work evaluates the effects of manganese (Mn) doping on the morpho-structural features, mechanical performance, and in vitro biological response of beta-tricalcium phosphate (beta-TCP) derived bioceramics for bone tissue engineering applications. Five different Mn doping levels (i.e., 0.01%, 0.05%, 0.1%, 0.5%, and 1 wt.%) were investigated, with the beta-TCP-based bioceramics being sintered at four temperatures (i.e., 1000, 1100, 1200, and 1300 degrees C). A densification improvement was induced when using Mn in excess of 0.05 wt.%; the densification remained stationary in the sintering temperature range of 1200 - 1300 degrees C. The structural analyses evidenced that all samples sintered at 1000 and 1100 degrees C were composed of beta-TCP as major phase and hydroxyapatite (HA) as a minor constituent (similar to 4-6 wt.%). At the higher temperatures (1200 and 1300 degrees C), the formation of alpha-TCP was signalled at the expense of both beta-TCP and HA. The Mn doping was evidenced by lattice parameters changes. The evolution of the phase weights is linked to a complex inter-play between the capacity of the compounds to incorporate Mn and the thermal decomposition kinetics. The Mn doping induced a reduction in the mechanical performance (in terms of compressive strength, Vickers hardness and elastic modulus) of the beta-TCP-based ceramics. The metabolic activity and viability of osteoblastic cells (MC3T3-E1) for the ceramics were studied in both powder and compacted pellet form. Ceramics with Mn doping levels lower than 0.1 wt.% yielded a more favorable microenvironment for the osteoblast cells with respect to the undoped beta-TCP. No cytotoxic effects were recorded up to 21 days. The Mn-doped beta-TCPs showed a significant increase (p < 0.01) in alkaline phosphatase activity with respect to pure beta-TCP.Article Citation Count: 12Production of the novel fibrous structure of poly(ε-caprolactone)/tri-calcium phosphate/hexagonal boron nitride composites for bone tissue engineering(Australian Ceramic Society, 2018) Ozbek, Burak; Erdogan, Barkin; Ekren, Nazmi; Oktar, Faik Nuzhet; Akyol, Sibel; Ben-Nissan, Besim; Gunduz, OguzhanNanofibrous composites of the poly(epsilon-caprolactone) (PCL), tricalcium phosphate (TCP), and hexagonal boron nitride (h-BN) with different compositions were manufactured by using an economical and non-complicated method called electrospinning. Produced fibrous structures showed no bead formation and had a clean surface. Characterization of the composites showed that particles were successfully mixed with polymer phase. High cell activity of SaOS-2 cells on the composites was observed with SEM images. In addition, fibrous scaffolds are biocompatible with human bone tissue and are highly degradable.Article Citation Count: 21Study on the cytocompatibility, mechanical and antimicrobial properties of 3D printed composite scaffolds based on PVA/ Gold nanoparticles (AuNP)/ Ampicillin (AMP) for bone tissue engineering(Elsevier, 2021) Şaşmazel, Hilal Türkoğlu; Midha, Swati; Yuca, Esra; Tukay, Ari; Sasmazel, Hilal Turkoglu; Kalaskar, Deepak M.; Gunduz, Oguzhan; Metallurgical and Materials EngineeringOver the years, gold nanoparticles (AuNP) have been widely used in several biomedical applications related to the diagnosis, drug delivery, bio-imaging, photo-thermal therapy and regenerative medicine, owing to their unique features such as surface plasmon resonance, fluorescence and easy surface functionality. Recent studies showed that gold nanoparticles display positive effect on osteogenic differentiation. In line with this effect, 3-Dimesional (3D) scaffolds that can be used in bone tissue were produced by exploiting the properties of gold nanoparticles that increase biocompatibility and support bone tissue development. In addition, ampicillin was added to the scaffolds containing gold nanoparticles as a model drug to improve its antimicrobial properties. The scaffolds were produced as composites of polyvinyl alcohol (PVA) main matrix as PVA, PVA/AuNP, PVA/Ampicillin (AMP) and PVA/AuNP/AMP. Scanning Electron Microscopy (SEM) Fourier Transform Infrared Spectroscopy (FTIR), tensile measurement tests, and in vitro applications of 3D scaffolds were performed. As depicted by SEM, scaffolds were produced at pore sizes appropriate for bone tissue regeneration. According to FTIR results, there was no modification observed in the AMP, PVA and gold nanoparticles due to mixing in the resultant scaffolds. In vitro results show that 3D printed composite scaffold based on PVA/AuNP/AMP are biocompatible, osteo-inductive and exhibit antimicrobial properties, compared to PVA scaffolds. This study has implications for addressing infections during orthopedic surgeries. The PVA-based gold nanoparticle 3D tissue scaffold study containing ampicillin covers a new study compared to other articles based on gold nanoparticles.Article Citation Count: 12Synthesis and characterization of antibacterial drug loaded β-tricalcium phosphate powders for bone engineering applications(Springer, 2020) Özkan, Ozan; Ekren, Nazmi; Kilic, Osman; Oktar, Faik N.; Mahirogullari, Mahir; Ozkan, Ozan; Gunduz, Oguzhan; Metallurgical and Materials EngineeringPowders of beta-tricalcium phosphate [beta-TCP, beta-Ca-3(PO4)(2)] and composite powders of beta-TCP and polyvinyl alcohol (PVA) were synthesized by using wet precipitation methods. First, the conditions for the preparation of single phase beta-TCP have been delineated. In the co-precipitation procedure, calcium nitrate and diammonium hydrogen phosphate were used as calcium and phosphorous precursors, respectively. The pH of the system was varied in the range 7-11 by adding designed amounts of ammonia solution. The filtered cakes were desiccated at 80 degrees C and subsequently calcined at different temperatures in the range between 700-1100 degrees C. Later on, rifampicin form II was used to produce drug-loaded beta-TCP and PVA/beta-TCP powders. All the synthesized materials have been characterized from morphological (by scanning electron microscopy) and structural-chemical (by X-ray diffraction and Fourier transform infrared spectroscopy) point of view. The drug loading capacity of the selected pure beta-TCP powder has been assessed. The biological performance (cytocompatibility in fibroblast cell culture and antibacterial efficacy against Escherichia coli and Staphylococcus aureus) has been tested with promising results. Application perspectives of the designed drug-bioceramic-polymer blends are advanced and discussed. [GRAPHICS] .