WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 2Citation - Scopus: 2Fabrication of Bioactive Helix Aspersa Extract-Loaded Chitosan-Based Bilayer Wound Dressings for Skin Tissue Regeneration(Amer Chemical Soc, 2024) Perpelek, Merve; Tıhmınlıoğlu, Funda; Tamburaci, Sedef; Karakasli, Ahmet; Tihminlioglu, FundaIn recent years, there has been a notable shift toward exploring plant and animal extracts for the fabrication of tissue engineering structures that seamlessly integrate with the human body, providing both biological compatibility and physical reinforcement. In this particular investigation, we synthesized bilayer wound dressings by incorporating snail (Helix aspersa) secretions, comprising mucus and slime, into chitosan matrices via lyophilization and electrospinning methodologies. A nanofiber layer was integrated on top of the porous structure to mimic the epidermal layer for keratinocyte activity as well as acting as an antibacterial barrier against possible infection, whereas a porous structure was designed to mimic the dermal microenvironment for fibroblast activity. Comprehensive assessments encompassing physical characterization, antimicrobial efficacy, in vitro bioactivity, and wound healing potential were conducted on these bilayer dressings. Our findings revealed that the mucus and slime extract loading significantly altered the morphology in terms of nanofiber diameter and average pore size. Snail extracts loaded on a nanofiber layer of bilayer dressings showed slight antimicrobial activity against Staphylococcus epidermidis and Escherichia coli. An in vitro release study of slime extract loaded in the nanofiber layer indicated that both groups 1 and 2 showed a burst release up to 6 h, and a sustained release was observed up to 96 h for group 1, whereas slime extract release from group 2 continued up to 72 h. In vitro bioactivity assays unveiled the favorable impact of mucus and slime extracts on NIH/3T3 fibroblast and HS2 keratinocyte cell attachment, proliferation, and glycosaminoglycan synthesis. Furthermore, our investigations utilizing the in vitro scratch assay showcased the proliferative and migratory effects of mucus and slime extracts on skin cells. Collectively, our results underscore the promising prospects of bioactive snail secretion-loaded chitosan constructs for facilitating skin regeneration and advancing wound healing therapies.Article Citation - WoS: 17Citation - Scopus: 16Development of Cissus Quadrangularis-Loaded Poss-Reinforced Chitosan-Based Bilayer Sponges for Wound Healing Applications: Drug Release and in Vitro Bioactivity(American Chemical Society, 2023) Değer Aker, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, FundaNowadays, antibiotic-loaded biomaterials have been widelyusedin wound healing applications. However, the use of natural extractshas come into prominence as an alternative to these antimicrobialagents in the recent period. Among natural sources, Cissus quadrangularis (CQ) herbal extract is usedfor treatment of bone and skin diseases in ayurvedic medicine dueto its antibacterial and anti-inflammatory effects. In this study,chitosan-based bilayer wound dressings were fabricated with electrospinningand freeze-drying techniques. CQ extract-loaded chitosan nanofiberswere coated on chitosan/POSS nanocomposite sponges using an electrospinningmethod. The bilayer sponge is designed to treat exudate wounds whilemimicking the layered structure of skin tissue. Bilayer wound dressingswere investigated with regard to the morphology and physical and mechanicalproperties. In addition, CQ release from bilayer wound dressings and in vitro bioactivity studies were performed to determinethe effect of POSS nanoparticles and CQ extract loading on NIH/3T3and HS2 cells. The morphology of nanofibers was investigated withSEM analysis. Physical characteristics of bilayer wound dressingswere determined with FT-IR analysis, swelling study, open porositydetermination, and mechanical test. The antimicrobial activity ofCQ extract released from bilayer sponges was investigated with a discdiffusion method. Bilayer wound dressings' in vitro bioactivity was examined using cytotoxicity determination, woundhealing assay, proliferation, and the secretion of biomarkers forskin tissue regeneration. The nanofiber layer diameter was obtainedin the range of 77.9-97.4 nm. The water vapor permeabilityof the bilayer dressing was obtained as 4021 to 4609 g/m(2)day, as it is in the ideal range for wound repair. The release ofthe CQ extract over 4 days reached 78-80% cumulative release.The release media were found to be antibacterial against Gram-negativeand Gram-positive bacteria. In vitro studies showedthat both CQ extract and POSS incorporation induced cell proliferationas well as wound healing activity and collagen deposition. As a result,CQ-loaded bilayer CHI-POSS nanocomposites were found as a potentialcandidate for wound healing applications.Article Citation - WoS: 11Fabrication of Helix Aspersa Extract Loaded Gradient Scaffold With an Integrated Architecture for Osteochondral Tissue Regeneration: Morphology, Structure, and in Vitro Bioactivity [2](American Chemical Society, 2023) Tamburacı, Sedef; Perpelek, Merve; Aydemir, Selma; Baykara, Başak; Havıtçıoğlu, Hasan; Tıhmınlıoğlu, FundaRegeneration of osteochondral tissue with its layered complex structure and limited self-repair capacity has come into prominence as an application area for biomaterial design. Thus, literature studies have aimed to design multilayered scaffolds using natural polymers to mimic its unique structure. In this study, fabricated scaffolds are composed of transition layers both chemically and morphologically to mimic the gradient structure of osteochondral tissue. The aim of this study is to produce gradient chitosan (CHI) scaffolds with bioactive snail (Helix aspersa) mucus (M) and slime (S) extract and investigate the structures regarding their physicochemical, mechanical, and morphological characteristics as well as in vitro cytocompatibility and bioactivity. Gradient scaffolds (CHI-M and CHI-S) were fabricated via a layer-by-layer freezing and lyophilization technique. Highly porous and continuous 3D structures were obtained and observed with SEM analysis. In addition, scaffolds were physically characterized with water uptake test, micro-CT, mechanical analysis (compression tests), and XRD analysis. In vitro bioactivity of scaffolds was investigated by co-culturing Saos-2 and SW1353 cells on each compartment of gradient scaffolds. Osteogenic activity of Saos-2 cells on extract loaded gradient scaffolds was investigated in terms of ALP secretion, osteocalcin (OC) production, and biomineralization. Chondrogenic bioactivity of SW1353 cells was investigated regarding COMP and GAG production and observed with Alcian Blue staining. Both mucus and slime incorporation in the chitosan matrix increased the osteogenic differentiation of Saos-2 and SW1353 cells in comparison to the pristine matrix. In addition, histological and immunohistological staining was performed to investigate ECM formation on gradient scaffolds. Both characterization and in vitro bioactivity results indicated that CHI-M and CHI-S scaffolds show potential for osteochondral tissue regeneration, mimicking the structure as well as enhancing physical characteristics and bioactivity. © 2023 The Authors. Published by American Chemical Society.Article Citation - WoS: 23Citation - Scopus: 26Fish scale containing alginate dialdehyde-gelatin bioink for bone tissue engineering(IOP Publishing Ltd, 2023) Özenler, Aylin Kara; Distler, Thomas; Tıhmınlıoğlu, Funda; Boccaccini, Aldo RThe development of biomaterial inks suitable for biofabrication and mimicking the physicochemical properties of the extracellular matrix is essential for the application of bioprinting technology in tissue engineering (TE). The use of animal-derived proteinous materials, such as jellyfish collagen, or fish scale (FS) gelatin (GEL), has become an important pillar in biomaterial ink design to increase the bioactivity of hydrogels. However, besides the extraction of proteinous structures, the use of structurally intact FS as an additive could increase biocompatibility and bioactivity of hydrogels due to its organic (collagen) and inorganic (hydroxyapatite) contents, while simultaneously enhancing mechanical strength in three-dimensional (3D) printing applications. To test this hypothesis, we present here a composite biomaterial ink composed of FS and alginate dialdehyde (ADA)-GEL for 3D bioprinting applications. We fabricate 3D cell-laden hydrogels using mouse pre-osteoblast MC3T3-E1 cells. We evaluate the physicochemical and mechanical properties of FS incorporated ADA-GEL biomaterial inks as well as the bioactivity and cytocompatibility of cell-laden hydrogels. Due to the distinctive collagen orientation of the FS, the compressive strength of the hydrogels significantly increased with increasing FS particle content. Addition of FS also provided a tool to tune hydrogel stiffness. FS particles were homogeneously incorporated into the hydrogels. Particle-matrix integration was confirmed via scanning electron microscopy. FS incorporation in the ADA-GEL matrix increased the osteogenic differentiation of MC3T3-E1 cells in comparison to pristine ADA-GEL, as FS incorporation led to increased ALP activity and osteocalcin secretion of MC3T3-E1 cells. Due to the significantly increased stiffness and supported osteoinductivity of the hydrogels, FS structure as a natural collagen and hydroxyapatite source contributed to the biomaterial ink properties for bone engineering applications. Our findings indicate that ADA-GEL/FS represents a new biomaterial ink formulation with great potential for 3D bioprinting, and FS is confirmed as a promising additive for bone TE applications.Article Citation - WoS: 3Citation - Scopus: 4Microfluidic-Assisted Preparation of Nano and Microscale Chitosan Based 3d Composite Materials: Comparison With Conventional Methods(Wiley, 2022) Kimna, Ceren; Değer, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, FundaAlthough nanofillers contribute to improved physical characteristics and biological functionalities of polymer-based biomaterials, their dispersion in polymer matrices is still a challenging issue in terms of obtaining consistency for the inherent properties. To tackle this problem, homogenization techniques are applied to disperse the nanofillers in such polymers, however, these methods can cause undesired changes especially in the rheological properties and the physical structure of the biopolymer matrices. Recently, as a novel homogenization technique, microfluidization has been used to homogenize polymer nanocomposites to minimize these limitations. In this study, two different nanocomposite structures as chitosan/montmorillonite (CS/MMT) and chitosan/polyhedral oligomeric silsesquioxane nanocages (CS/POSS) were homogenized with microfluidization and investigated in terms of physical alterations. Furthermore, the effect of microfluidizer technique on material characteristics was compared with conventional homogenization techniques, i.e., ultrasonic bath and sonication in terms of solution, nano – (e.g., hydrodynamic size, drug encapsulation) and macroscopic material characteristics (e.g., porosity, mechanical properties, swelling and thermal degradation). It was found that the microfluidizer homogenization improves the physical characteristics in both nano and macroscale materials: Nanospheres obtained from CS/MMT composites showed enhanced stability, uniform size distribution (<100 nm, PDI: [removed]50%) whereas 3D porous CS/POSS scaffolds showed improved structural uniformity (i.e., homogeneous and interconnected microstructure) and enhanced thermal and mechanical properties. The obtained results indicate that the microfluidizer homogenization ensures a successful nanofiller dispersion in polymer matrices, thereby improving the biomaterial characteristics impressively compared to the sonication methods.Article Citation - WoS: 51Citation - Scopus: 583d Printed Gelatin/Decellularized Bone Composite Scaffolds for Bone Tissue Engineering: Fabrication, Characterization and Cytocompatibility Study(Elsevier, 2022) Kara, Aylin; Distler, Thomas; Polley, Christian; Schneidereit, Dominik; Seitz, Hermann; Friedrich, Oliver; Tıhmınlıoğlu, Funda; Boccaccini, Aldo RThree-dimensional (3D) printing technology enables the design of personalized scaffolds with tunable pore size and composition. Combining decellularization and 3D printing techniques provides the opportunity to fabricate scaffolds with high potential to mimic native tissue. The aim of this study is to produce novel decellularized bone extracellular matrix (dbECM)-reinforced composite-scaffold that can be used as a biomaterial for bone tissue engineering. Decellularized bone particles (dbPTs, ∼100 μm diameter) were obtained from rabbit femur and used as a reinforcement agent by mixing with gelatin (GEL) in different concentrations. 3D scaffolds were fabricated by using an extrusion-based bioprinter and crosslinking with microbial transglutaminase (mTG) enzyme, followed by freeze-drying to obtain porous structures. Fabricated 3D scaffolds were characterized morphologically, mechanically, and chemically. Furthermore, MC3T3-E1 mouse pre-osteoblast cells were seeded on the dbPTs reinforced GEL scaffolds (GEL/dbPTs) and cultured for 21 days to assess cytocompatibility and cell attachment. We demonstrate the 3D-printability of dbPTs-reinforced GEL hydrogels and the achievement of homogenous distribution of the dbPTs in the whole scaffold structure, as well as bioactivity and cytocompatibility of GEL/dbPTs scaffolds. It was shown that Young's modulus and degradation rate of scaffolds were enhanced with increasing dbPTs content. Multiphoton microscopy imaging displayed the interaction of cells with dbPTs, indicating attachment and proliferation of cells around the particles as well as into the GEL-particle hydrogels. Our results demonstrate that GEL/dbPTs hydrogel formulations have potential for bone tissue engineering.Article Citation - WoS: 22Citation - Scopus: 23Bioactive Snail Mucus-Slime Extract Loaded Chitosan Scaffolds for Hard Tissue Regeneration: the Effect of Mucoadhesive and Antibacterial Extracts on Physical Characteristics and Bioactivity of Chitosan Matrix(IOP Publishing, 2021) Perpelek, Merve; Tamburacı, Sedef; Aydemir, Selma; Tıhmınlıoğlu, Funda; Baykara, Başak; Karakaşlı, Ahmet; Havıtçıoğlu, HasanBiobased extracts comprise various bioactive components and they are widely used in tissue engineering applications to increase bioactivity as well as physical characteristics of biomaterials. Among animal sources, garden snail Helix aspersa has come into prominence with its antibacterial and regenerative extracts and show potential in tissue regeneration. Thus, in this study, bioactive H. aspersa extracts (slime, mucus) were loaded in chitosan (CHI) matrix to fabricate porous scaffolds for hard tissue regeneration. Physical, chemical properties, antimicrobial activity was determined as well as in vitro bioactivity for bone and cartilage regeneration. Mucus and slime incorporation enhanced mechanical properties and biodegradation rate of CHI matrix. Scanning electron microscopy images showed that the average pore size of the scaffolds decreased with higher extract content. Mucus and slime extracts showed antimicrobial effect on two bacterial strains. In vitro cytotoxicity, osteogenic and chondrogenic activity of the scaffolds were evaluated with Saos-2 and SW1353 cell lines in terms of Alkaline phosphatase activity, biomineralization, GAG, COMP and hydroxyproline content. Cell viability results showed that extracts had a proliferative effect on Saos-2 and SW1353 cells when compared to the control group. Mucus and slime extract loading increased osteogenic and chondrogenic activity. Thus, the bioactive extract loaded CHI scaffolds showed potential for bone and cartilage regeneration with enhanced physical properties and in vitro bioactivity.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.Conference Object Citation - WoS: 16Thermal Characterization of Ag and Ag Plus N Ion Implanted Ultra-High Molecular Weight Polyethylene (uhmwpe)(Elsevier Ltd., 2007) Urkaç, Emel Sokullu; Oztarhan, A.; Tıhmınlıoğlu, Funda; Kaya, N.; Ila, D.; Muntele, C.; Tek, Z.Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 10(17) ion/cm(2) and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE. (c) 2007 Elsevier B.V. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 9Polymeric Thermal Analysis of C+h and C+h+ar Ion Implanted Uhmwpe Samples(Elsevier Ltd., 2007) Kaya, N.; Öztarhan, Ahmet M.; Urkaç, Emel Sokullu; Ila, D.; Budak, S.; Oks, E.; Tıhmınlıoğlu, Funda; Muntele, C.Chemical surface characterization of C + H hybrid ion implanted UHMWPE samples were carried out using DSC (differential scanning calorimeter) and TGA (thermal gravimetric analysis) techniques. Samples were implanted with a fluence of 10(17) ion/cm(2) and an extraction voltage of 30 kV. The study of TGA and DSC curves showed that: (1) Polymeric decomposition temperature increased, (2) T-m, Delta C-p and Delta H-m values changed while Delta C-p and Delta H-m increased. T-g value could not be measured, because of some experimental limitations. However, the increase in Delta H-m values showed that T-g values increased, (3) the branch density which indicated the increase in number of cross-link (M-c) decreased in ion implanted samples and (4) increase in Delta H-m values indicated increase in crystallinity of implanted surface of UHMWPE samples.