PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
Browse
14 results
Search Results
Now showing 1 - 10 of 14
Review Citation - WoS: 13Citation - Scopus: 13Oxygen Delivery Biomaterials in Wound Healing Applications(WILEY-V C H VERLAG GMBH, 2023) Bayraktar, Sema; Üstün, Cansu; Kehr, Nermin SedaOxygen (O2) delivery biomaterials have attracted great interest in the treatment of chronic wounds due to their potential applications in local and continuous O2 generation and delivery, improving cell viability until vascularization occurs, promoting structural growth of new blood vessels, simulating collagen synthesis, killing bacteria and reducing hypoxia-induced tissue damage. Therefore, different types of O2 delivery biomaterials including thin polymer films, fibers, hydrogels, or nanocomposite hydrogels have been developed to provide controlled, sufficient and long-lasting O2 to prevent hypoxia and maintain cell viability until the engineered tissue is vascularized by the host system. These biomaterials are made by various approaches, such as encapsulating O2 releasing molecules into hydrogels, polymer microspheres and 3D printed hydrogel scaffolds and adsorbing O2 carrying reagents into polymer films of fibers. In this article, different O2 generating sources such as solid inorganic peroxides, liquid peroxides, and photosynthetic microalgae, and O2 carrying perfluorocarbons and hemoglobin are presented and the applications of O2 delivery biomaterials in promoting wound healing are discussed. Furthermore, challenges encountered and future perspectives are highlighted. Oxygen delivery (O2) biomaterials have attracted great interest in the treatment of chronic wounds due to their ability to continuously deliver oxygen and support cell viability. Therefore, various O2 generating sources such as solid inorganic peroxides, liquid peroxides and photosynthetic microalgae, and O2-carrying perfluorocarbons and hemoglobin are incorporated into different biomaterial networks for wound healing applications.imageArticle Citation - WoS: 9Citation - Scopus: 8Development of a New Electrochemical Sensor Based on Molecularly Imprinted Biopolymer for Determination of 4,4'-methylene Diphenyl Diamine(MDPI, 2023) Ghaani, Masoud; Büyüktaş, Duygu; Carullo, Daniele; Farris, StefanoA new molecularly imprinted electrochemical sensor was proposed to determine 4,4' methylene diphenyl diamine (MDA) using molecularly imprinted polymer-multiwalled carbon nanotubes modified glassy carbon electrode (MIP/MWCNTs/GCE). GCE was coated by MWCNTs (MWCNTs/GCE) because of their antifouling qualities and in order to improve the sensor sensitivity. To make the whole sensor, a polymeric film made up of chitosan nanoparticles was electrodeposited by the cyclic voltammetry method on the surface of MWCNTs/GCE in the presence of MDA as a template. Different parameters such as scan cycles, elution time, incubation time, molar ratio of template molecules to functional monomers, and pH were optimized to increase the performance of the MIP sensor. With a detection limit of 15 nM, a linear response to MDA was seen in the concentration range of 0.5-100 mu M. The imprinting factor (IF) of the proposed sensor was also calculated at around 3.66, demonstrating the extremely high recognition performance of a MIP/MWCNT-modified electrode. Moreover, the sensor exhibited good reproducibility and selectivity. Finally, the proposed sensor was efficiently used to determine MDA in real samples with satisfactory recoveries ranging from 94.10% to 106.76%.Article Citation - WoS: 52Citation - Scopus: 54Development of Si Doped Nano Hydroxyapatite Reinforced Bilayer Chitosan Nanocomposite Barrier Membranes for Guided Bone Regeneration(Elsevier, 2021) Tamburacı, Sedef; Tıhmınlıoğlu, FundaGuided Bone Regeneration (GBR) is a widely used process for the treatment of periodontal defects to prevent the formation of surrounding soft tissue at the periodontal defect and to provide hard tissue regeneration. Recently GBR designs have focused on the development of resorbable natural polymer-based barrier membranes due to their biodegradability and excellent biocompatibility. The aim of this study is to fabricate a novel bilayer nanocomposite membrane with microporous sublayer composed of chitosan and Si doped nanohydroxyapatite particles (Si-nHap) and chitosan/PEO nanofiber upper layer. Bilayer membrane was designed to prevent epithelial and fibroblastic cell migration and growth impeding bone formation with its upper layer and to support osteogenic cell bioactivity at the defect site with its sublayer. Microporous and nanofiber layers were fabricated by using freeze-drying and electrospinning techniques respectively. The effect of Si-nHap content on the morphological, mechanical and physical properties of the composites were investigated using SEM, AFM, micro-Ct, compression test, water uptake capacity and enzymatic degradation study. Antimicrobial properties of nanocomposite membranes were investigated with tube dilution and disk diffusion methods. In vitro cytotoxicity of bilayer membranes was evaluated. Saos-2 and NIH/3T3 proliferation studies were carried out on each layer. In vitro bioactivity of Saos-2 and NIH/3T3 cells were evaluated with ALP activity and hydroxyproline content respectively. Results showed that Si-nHap incorporation enhanced the mechanical and physical properties as well as controlling biodegradability of the polymer matrix. Besides, Si-nHap loading induced the bioactivity of Saos-2 cells by enhancing cell attachment, spreading and biomineralization on the material surface. Thus, results supported that designed bilayer nanocomposite membranes can be used as a potential biomaterial for guided bone regeneration in periodontal applications.Article Citation - WoS: 43Citation - Scopus: 47Bioactive Diatomite and Poss Silica Cage Reinforced Chitosan/Na-carboxymethyl Cellulose Polyelectrolyte Scaffolds for Hard Tissue Regeneration(Elsevier, 2019) Tamburacı, Sedef; Kimna, Ceren; Tıhmınlıoğlu, FundaRecently, natural polymers are reinforced with silica particles for hard tissue engineering applications to induce bone regeneration. In this study, as two novel bioactive agents, effects of diatomite and polyhedral oligomeric silsesquioxanes (POSS) on chitosan (CS)/Na-carboxymethylcellulose (Na-CMC) polymer blend scaffolds are examined. In addition, the effect of silica reinforcements was compared with Si-substituted nano-hydroxyapatite (Si-Hap) particles. The morphology, physical and chemical structures of the scaffolds were characterized with SEM, liquid displacement, FT-IR, mechanical analysis, swelling and degradation studies. The particle size and the crystal structure of diatomite, POSS and Si-Hap particles were determined with DLS and XRD analyses. In vitro studies were performed to figure out the cytotoxicity, proliferation, ALP activity, osteocalcin production and biomineralization to demonstrate the promising use of natural silica particles in bone regeneration. Freeze-dried scaffolds showed 190-307 mu m pore size range and 61-70% porosity. Both inorganic reinforcements increased the mechanical strength, enhanced the water uptake capacity and fastened the degradation rate. The nanocomposite scaffolds did not show any cytotoxic effect and enhanced the surface mineralization in osteogenic medium. Thus, diatomite and POSS cage structures can be potential reinforcements for nanocomposite design in hard tissue engineering applications.Article Citation - WoS: 46Citation - Scopus: 53Chitosan-Hybrid Poss Nanocomposites for Bone Regeneration: the Effect of Poss Nanocage on Surface, Morphology, Structure and in Vitro Bioactivity(Elsevier, 2020) Tamburacı, Sedef; Tıhmınlıoğlu, FundaPOSS, regarded as the smallest silica particle, is widely used as nanofiller in polymer systems. POSS-based nanocomposites are deduced as novel materials having potency for biomedical applications owing to the enhanced biocompatibility and physicochemical characteristics. The aim of this work was to integrate the beneficial features of chitosan (CS) and OctaTMA-POSS nanoparticle to design nanocomposite for bone tissue regeneration. The nanocomposite scaffolds were fabricated by freeze-drying. The effects of POSS incorporation on morphology and structure of CS matrix were examined. Bioactivity and osteogenic effects of the POSS nanoparticles were investigated with cytocompatibility, cell proliferation, alkaline phosphatase activity, osteocalcin production and biomineralization assays. PUSS incorporation altered the surface morphology by increasing surface roughness. Nanocomposite scaffolds with 82-90% porosity exhibited an increase in compression modulus of scaffolds (78-107 kPa) compared to control CS group (56 kPa). Results indicated that CS-POSS scaffolds were found cytocompatible with 3T3, MG-63 and Saos-2 cell lines. POSS incorporation showed promising effects on osteoblast adhesion and proliferation as well as increasing ALP activity, octeocalcin secretion and biomineralization of cells. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 9Citation - Scopus: 10Decontamination of Seeds Destined for Edible Sprout Production From Listeria by Using Chitosan Coating With Synergetic Lysozyme-Nisin Mixture(Elsevier, 2020) Sözbilen, Gözde Seval; Yemenicioğlu, AhmetThis study aimed at decontamination of seeds destined for edible sprout production from Listeria using chitosan (CS) coatings incorporated with synergetic lysozyme-nisin (LYS-NIS) mixtures. Low molecular weight (LMW) CS coating showed the highest potency against Listeria innocua, followed by medium molecular weight (MMW) and high molecular weight (HMW) CSs. The LMW CS film with LYS-NIS also caused almost 1.5-fold greater log reduction (similar to 5 log) in initial L. innocua load of broth culture than MMW and HMW CS films with LYS-NIS within 6 days. Moreover, LMW CS coating with LYS-NIS reduced the initial Listeria loads of inoculated mung beans, lentils, and wheats by 3.3, 3.4 and 4.1 log, respectively. Antimicrobial coating did not affect seed germination rates considerably. The LYS-NIS addition increased yellowness and opacity of films, and caused limited changes in their mechanical and morphological properties. LMW CS coating with LYS-NIS reduces risk of listeriosis from sprouted seeds.Article Citation - WoS: 30Citation - Scopus: 37Production and Characterization of a Novel Bilayer Nanocomposite Scaffold Composed of Chitosan/Si-nhap and Zein/Poss Structures for Osteochondral Tissue Regeneration(American Chemical Society, 2019) Tamburacı, Sedef; Çeçen, Berivan; Üstün, Özcan; Ergür, Bekir Uğur; Havıtçıoğlu, Hasan; Tıhmınlıoğlu, FundaOsteochondral tissue is hard to regenerate after injuries or degenerative diseases. Traditional treatments still have disadvantages, such as donor tissue availability, donor site morbidity, implant loss, and limited durability of prosthetics. Thus, recent studies have focused on tissue engineering strategies to regenerate osteochondral defects with different scaffold designs. Scaffolds have been developed from monolayer structures to bilayer scaffolds to repair the cartilage-bone interface and to support each tissue separately. In this study, Si-substituted nanohydroxyapatite particles (Si-nHap) and silica-based POSS nanocages were used as reinforcements in different polymer layers to mimic a cartilage-bone tissue interface. Chitosan and zein, which are widely used biopolymers, are used as polymer layers to mimic the structure. This study reports the development of a bilayer scaffold produced via fabrication of two different nanocomposite layers with different polymer-inorganic composites in order to satisfy the complex and diverse regenerative requirements of osteochondral tissue. The chitosan/Si-nHap microporous layer and the zein/POSS nanofiber layer were designed to mimic a bone-cartilage tissue interface. Bilayer scaffolds were characterized with SEM, compression, swelling, and biodegradation tests to determine morphological, physical, and mechanical properties. The results showed that the bilayer scaffold had a structure composed of microporous and nanofiber layers joined at a continuous interface with appropriate mechanical properties. Furthermore, in vitro cell culture studies have been performed with LDH, proliferation, fluorescence imaging, and ALP activity assays using osteosarcoma and chondrosarcoma cell lines. ALP expression levels provide a good illustration of the improved osteogenic potential of a porous chitosan/Si-nHap layer due to the Si-doped nHap incorporation. Histological data showed that both fiber and porous layers that mimic the cartilage and bone sections exhibit homogeneous cell distribution and matrix formation. Histochemical staining was used to determine the cell proliferation and ECM formation on each layer. In vitro studies indicated that zein-POSS/chitosan/Si-nHap nanocomposite bilayer scaffolds showed promising results for osteochondral regeneration. Copyright © 2019 American Chemical Society.Article Citation - WoS: 51Citation - Scopus: 60Biosilica Incorporated 3d Porous Scaffolds for Bone Tissue Engineering Applications(Elsevier Ltd., 2018) Tamburacı, Sedef; Tıhmınlıoğlu, FundaAs a natural and abundant silica mineral, diatomite particles (SiO2-nH2O) have been used in several areas such as filtration, photonics, sound and heat insulation, filler material and drug delivery due to its abundance, inexpensive cost, unique morphology and porous structure. But up to date, diatomite incorporated silica based scaffolds have not been used for bone tissue engineering applications. In the present study, the goal was to combine the useful biomaterial properties of both chitosan and diatomite as biocomposite organic/inorganic biomaterial for bone tissue engineering applications and optimize the silica content of the composites in order to obtain optimum morphological structure, high mechanical properties, enlarged surface area and enhanced cell proliferation. The effect of silica loading on the mechanical, morphological, chemical, and surface properties, wettability and biocompatibility of composite scaffolds were investigated. In addition, in vitro cytotoxicity and cellular activities including cell proliferation, ALP activity and biomineralization were investigated in order to determine biological activity of the composite scaffolds. Diatomite particles lead to enhancement in the water uptake capacity of scaffolds. Chitosan-silica composites exhibited 82–90% porosity. Wet chitosan-silica composite scaffolds exhibited higher compression moduli when compared to pure chitosan scaffold in the range of 67.3–90.1 kPa. Average pore size range of chitosan-diatomite composite scaffolds was obtained as 218-319 μm. In vitro results indicated that chitosan-diatomite composites did not show any cytotoxic effect on 3T3, MG-63 and Saos-2 cell lines. Scaffolds were found to be favorable for osteoblast proliferation. Diatomite incorporation showed promising effects on enhancing ALP activity as well as mineral formation on scaffold surface. Thus, the prepared scaffolds in this study can be considered prospective material for bone tissue engineering applications.Article Citation - WoS: 23Citation - Scopus: 27Novel Poss Reinforced Chitosan Composite Membranes for Guided Bone Tissue Regeneration(Springer Verlag, 2018) Tamburacı, Sedef; Tıhmınlıoğlu, FundaIn this study, novel composites membranes composed of chitosan matrix and polyhedral oligomeric silsesquioxanes (POSS) were fabricated by solvent casting method. The effect of POSS loading on the mechanical, morphological, chemical, thermal and surface properties, and cytocompatibility of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of Octa-TMA POSS® nanofiller to the chitosan matrix increased the surface roughness, protein adsorption and swelling capacity of membranes. The addition of POSS enhanced significantly the ultimate tensile strength and strain at break of the composite membranes up to 3 wt% POSS loaded samples. An increase of about 76% in tensile strength and of strain at break 1.28% was achieved for 3 wt% POSS loaded nanocomposite membranes compared with chitosan membranes. The presence of POSS filler into polymer matrix increased the plasma protein adsorption on the surface. Maximum protein capacity and swelling was obtained for 10 wt% loaded samples. High cell viability results were obtained with indirect extraction of chitosan/POSS composites. Besides, cell proliferation and ALP activity results showed that POSS incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. This novel composite membranes with tunable properties could be considered as a potential candidate for guided bone regeneration applicationsArticle Citation - WoS: 96Citation - Scopus: 113Hypericum Perforatum Incorporated Chitosan Films as Potential Bioactive Wound Dressing Material(Elsevier Ltd., 2017) Güneş, Seda; Tıhmınlıoğlu, FundaRecent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25–1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications.