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Öğe Bioactive coatings on biopolymer materials: evaluation of mechanical, physical, thermal, and in vitro properties(Springer, 2024) Oksuz, Kerim EmreThe aim of this study was to develop and characterize coatings of bioglass nanoparticles (BGNs) on biopolymer (poly [glycolide-co-L-lactide], (PGLA)) surgical sutures, and to investigate the effects of these coatings on the performance of the sutures as they slid through a skin substitute. Melt-derived BGNs were used to coat resorbable PGLA biopolymers, providing them with bioactivity, biocompatibility, and improved physical and mechanical properties. The structural, thermal, and physical properties of the coated and uncoated biopolymers were analyzed using Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy-Dispersive X-ray Spectroscopy (EDXS). The dissolution profiles and bioactivity of the BGNs-coated PGLA biopolymers were assessed through Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Tensile strength tests were conducted on the biopolymers before and after immersion in simulated body fluid to evaluate the impact of the BGNs coating on the degradation of PGLA biopolymers. Incorporating BGNs into PGLA resulted in improved tensile strength properties. The study also found that increasing the BGNs ions content facilitated the formation of a hydroxycarbonate apatite (HCA) layer in Dulbecco's Modified Eagle Medium and medium with L-glutamine and sodium bicarbonate solutions. In vitro bioactivity tests demonstrated that the coated suture biopolymers exhibited enhanced attachment, migration, and proliferation of fibroblasts, indicating favorable biocompatibility of the biomaterial for clinical applications.Öğe Boron-Doped Nano Hydroxyapatite Grafts for Bone Regeneration in Rat Mandibular Defects(Springernature, 2024) Demirkiran, Berat Baturay; Inan, Zeynep Deniz Sahin; Hamutoglu, Rasim; Oksuz, Kerim Emre; Hasbek, Zekiye; Altuntas, Emine ElifThe aim of this study was to evaluate the potential effects of boron-doped nano hydroxyapatite grafts on craniofacial bone regeneration in critical bone defects in the mandibular corpus of rats, in terms of scintigraphic and histopathological aspects. Forty Wistar albino rats, with an average weight of 200-220 g, aged 16-18 weeks, and all male, were used in the study. The rats were randomly assigned to five groups, each containing 8 rats, as follows: group C1 (no procedure applied to the mandible), group C2 (surgical defect created in the mandible but no treatment applied), group nHA (nano hydroxyapatite applied to the surgical defect area), group nHA + B1 (nano hydroxyapatite + 1% boron applied to the surgical defect area), and group nHA + B2 (nano hydroxyapatite + 2% boron applied to the surgical defect area). A standard 4 x 4 mm full-thickness transosseous bone defect was created in the mandibular corpus of all rats, except for those in group C1. The bone defect in the rats in group C2 was left to heal naturally. Nano hydroxyapatite (nHA), nano hydroxyapatite + 1% boron, and nano hydroxyapatite + 2% boron were applied to the surgical defect areas of the other three groups, respectively. Bone scintigraphy was performed on all rats on days 0 (following the surgical procedure) and 28 of the experimental period. At the end of the 28th day, the animals were sacrificed, and tissue samples were collected for histological examination. A standard grading system was used to evaluate fracture healing. When the groups were compared in terms of bone healing histopathological scores, a statistically significant difference was observed between group C1 and the other groups (p < 0.005). In the statistical evaluation made according to the histopathological mean scores, the least improvement was observed in group C2. No statistically significant difference was observed between group nHA and group nHA + B1 and group C2 and between group nHA and group nHA + B1 in terms of bone healing scores (p > 0.005). A statistically significant difference was found between group nHA + B2 and group C2 (p = 0.026). Although there was no statistically significant difference in histopathological scores, the mean score closest to group C1 was observed in group nHA + B2. A statistically significant difference was observed between the groups in the scintigraphic evaluation performed on the 28th day of the experimental procedure, and the difference was between group C1 and group nHA + B1 and between group nHA and group nHA + B1 (p = 0.004; p = 0.028, p < 0.005). In the comparison of the values obtained on days 0 and 28 within the group, a statistically significant change was observed in group nHA + B1 and group nHA + B2 (p < 0.005). When the results of the present study were evaluated, it was thought that the boron-doped nHA graft biomaterials may have positive effects on bone healing. Providing a different perspective for the development of an alternative new treatment modality that can be locally applied in the treatment of fractures a serious and common health problem can be interpreted as an important outcome of the present study. We believe that this study will serve as a preliminary study for more comprehensive future studies on this subject.Öğe Calcium phosphate nano powder biosynthesis from sea urchin shells: a response surface approach(Springer, 2024) Oksuz, Kerim Emre; Sen, Iker; Ersan, MehtapIn this experimental study, calcium phosphate Ca-3(PO4)(2) nanopowders, in the form of nano-hydroxyapatite (n-HA), were successfully synthesized from sea urchin shells (Diadema setosum, Leske, 1778) via a process involving precipitation and heat treatment method at various calcination temperatures (800 to 1200 degrees C). The optimal conditions for producing n-HA with maximum free CaO content were determined using response surface methodology (RSM) through a Box-Behnken Design. Key findings demonstrated that calcination temperature, calcination time, and ball-milling time significantly influenced the free CaO content. The study identified that a calcination temperature of 1100.73 degrees C for 2.78 h for CaO derived from sea urchin shells, combined with a ball-milling time of 66.37 h, resulted in the highest purity of n-HA. The biosynthesized n-HA exhibited desirable characteristics for bone and dental restoration applications, as confirmed by comprehensive analyses of functional group vibrations, chemical structure/composition, molecular interactions, surface morphology, and particle size distribution. These findings underscore the potential of using invasive sea urchin shells as a sustainable and effective source for n-HA production in biomedical applications.Öğe CHARACTERIZATION AND MECHANICAL PROPERTIES OF PM Fe-Cu/SiCp ALLOYS(TRANS TECH PUBLICATIONS LTD, 2014) Oksuz, Kerim Emre; Gun, Tarik; Simsir, Mehmet; Parsa, MHFe-Cu-Co alloys are the new generation of metal matrix for diamonds in PM processed cutting tools. These alloys were created with the purpose of reducing the cobalt content in diamond tools. Nevertheless, little have been published, once this is a matter of industrial interest. In this work, samples of Fe-(10-20)wt. %Cu and Fe-(10-20) wt. %Cu -1%wt SiCp alloys were processed by cold pressing at 350 MPa, followed by sintering at 1150 degrees C/30 min. under argon atmosphere. After sintering, a study of structural and microstructural analyses was conducted. Brinell hardness and wear tests were carried out in the metal matrix, as well as the wear resistance of the metal matrix composites. The composition Fe-20%wt Cu-1%wt SiCp was the best among the studied ones, because it presented the best results of hardness and wear resistance.Öğe Effect of Calcination on Microstructure Development and Properties of Hydroxyapatite Powders Extracted from Human and Bovine Bones(INDIAN CERAMIC SOC, 2019) Oksuz, Kerim Emre; Kilinc, Seyran; Ozer, AliThis study represents a comprehensive discussion of hydroxyapatite (HAp) formation from human and bovine bones. The phase formation and surface morphologies of prepared HAp powders were determined by XRD and SEM analyses, respectively. TEM was employed to understand the internal compositions with high magnifications and particle size. FT-IR characterizations provided information about molecular interactions and structures. In order to understand the effect of heat treatment at different temperatures and ultimately to get the desired morphology/particle size of the HAp powders derived from human and bovine, the powder samples were calcined at 700 degrees to 1100 degrees C with an interval of 100 degrees C. At 700 degrees C, the organic components were removed and finally, a carbonate apatite was obtained. The degree of crystallinity and crystallite size were noticed to increase progressively with calcination temperature. The overall results showed that the calcination temperature highly influenced the properties of HAp powders derived from human and bovine bone samples. As expected, higher temperatures led to more pure form of HAp with higher degree of crystallinity, larger crystallite size, and a less porous structure. Besides, the human bone structure, in contrary to the bovine bone, did not show temperature sensitivity by means of crystallite size increase.Öğe Effect of Composition and Sintering Temperature on the Structure and Properties of Porous Bioactive Glass Scaffolds(CHIANG MAI UNIV, FAC SCIENCE, 2019) Oksuz, Kerim EmreCalcium phosphate glasses have a potential use as bone substituting applications, because of their chemical composition is closely similar to that of natural bone. The implant glass can be slowly replaced by regenerating tissue and has good biocompatibility and non-toxicity. In this experimental study, porous bioglass-ceramics were prepared via natural fibers (wood dust) burning-out process. Three glass batches were prepared in the ZrO2/Al2O3-CaO-P2O5 glass system, then melted, quenched and milled to give fine glass powders. Bioglass composites were sintered in a furnace at different sintering temperatures (750 degrees C, 850 degrees C and 950 degrees C) for 3 hours. The sintered bioglass samples were analyzed by field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) for further investigation of grain morphology, shape, size and phase formation. The bulk density, the apparent porosity and water absorption of the sintered samples were measured using the Archimedes' principle. The mechanical properties (micro-hardness in this case) and in-vitro dissolution behavior of those bioglasses were investigated and discussed.Öğe From biopolymer matrix to medicine: the drug delivery dynamics of amoxicillin-loaded PVA/SA/ZnONPs hydrogels(Taylor & Francis Ltd, 2024) Abuhamed, Nader; Arslan, Saynur; Oksuz, Kerim Emre; Dincer, EmineThis research presents a comprehensive study of Polyvinyl alcohol/Sodium alginate/Zinc oxide nanoparticles (PVA/SA/ZnONPs) and PVA/SA/ZnONPs/Amoxicillin (AMX) hydrogels, demonstrating their potential for various biomedical applications. A comparative analysis of their swelling behavior, in vitro biodegradation, antibacterial properties, and drug release profiles was performed. The hydrogels demonstrated distinct swelling characteristics, with the PVA/SA/ZnONPs/AMX hydrogel showing a higher initial swelling ratio. This behavior, likely due to the increased hydrophilicity from AMX, subsequently decreased over time, indicating AMX release into the environment. The biodegradation study highlighted a faster degradation rate for the PVA/SA/ZnONPs/AMX hydrogel, suggesting its suitability for applications requiring rapid degradation, such as drug delivery systems. Regarding antibacterial properties, the PVA/SA/ZnONPs/AMX hydrogel showed significant antibacterial activity against both Escherichia coli and Staphylococcus aureus, making it a strong candidate for biomedical applications necessitating antibacterial activity. Additionally, the drug release study presented a gradual and controlled release of AMX from the hydrogels over time, demonstrating their potential for sustained drug delivery applications. This research underscores the potential of PVA/SA/ZnONPs/AMX hydrogel, particularly for biomedical applications, especially in wound healing and drug delivery domains, given its potent antibacterial properties and controlled drug release behavior.Öğe Investigation of the structure and hardness properties of Anodonta anatina mussel shells(Ege Univ, Fac Fisheries, 2023) Oksuz, Kerim Emre; Sereflisan, HulyaIn this study, the shell structure of the freshwater mussel Anodonta anatina (Linnaeus, 1758) which has a widespread population in Golbasi Lake (Hatay) and is not economically exploited, was microscopically examined at a morphological level. It was determined that the shells of Anodonta anatina, which are not under significant fishing pressure, are mostly found discarded along the shores of the lake. This mussel species is important as a composite biological material with multifunctional roles in freshwater ecology. Considering the potential use of freshwater mussel shells as a biological material, an assessment of the shell structure, physical properties, mechanical strength, shell microstructure, and morphological characteristics of A. anatina was conducted. When cross-sections of the shell taken from the umbo, middle periostracum, and the region close to the pallial edge were examined in the dorsal-ventral direction, it was determined that the periostracum layer in the umbo region had a more prismatic and polygonal structure. The interior of the shell was found to consist of a shiny nacreous layer. In nacreous shell sections, it was observed that the nacreous layer contained more distinct layers near the pallial edge. Vickers microhardness tests were performed on individual shells, and it was found that the hardness value of the inner layer was the highest (625.5 +/- 172.7 HV), while the outer layer had a lower hardness value (531.5 +/- 110.7 HV). Based on XRF data, it was shown that the seashell powder is mainly composed of calcium oxide (98.8% wt., CaO) as a biological material.Öğe Investigation of the wear behavior of B4C reinforced Fe/Co matrix composites produced by hot press(ELSEVIER SCIENCE BV, 2011) Simsir, Mehmet; Oksuz, Kerim Emre; Sahin, Yusuf; Guagliano, M; Vergani, LDiamond tools are widely used for sawing, drilling and grinding materials. The extreme hardness of diamonds and the strength of the diamond/matrix combination make these tools superior. In this experimental study, diamond impregnated in Fe-Co matrix are processed by powder metallurgy method using hot pressing technique. The effects of Fe and boron carbide (B4C) additions on characteristic of diamond impregnated Co matrix composites have been investigated. The composite reinforced with and without B4C samples having three different compositions (different Fe / Co ratio) were produced under 25 MPa pressure and sintered at 900 degrees C temperature. After sinterning, hardness test was carried out and wear tests were performed by a pin-on-disc type of wear configuration. The experimental results showed that addition of Fe caused decreasing in the hardness of the matrix, and also reinforcing of B4C unaffected on the hardness of the composite. It is observed that wear resistance of B4C reinforced Fe-Co metal matrix composite was greater than that of composite without reinforcement (B4C). Furthermore, the characterization of produced composites using SEM and EDS analyses is done. (C) 2011 Published by Elsevier Ltd. Selection and peer review under responsibilitu of ICM11Öğe Microstructural evaluation and characterization of solid-state reaction of B2O3 doped BaZrxTi1-xO3 ceramics(SPRINGER, 2015) Oksuz, Kerim Emre; Sen, Saduman; Sen, Ugur0.5 wt. % B2O3 doped BaZrxTi1-xO3 ceramics (x = 0, 0.1, 0.2, 0.3, 0.4) were synthesized by adapting the solid-state synthesis method. B2O3 used as a sintering additive in the BT and BZT ceramics can vaporize easily at high temperatures, so it can be adopted as a vapor dopant. The influence of the substitution content on the crystallographic structure, phase transition, grain size, microstructure and physical properties of BT and BZT ceramics were discussed. Materials Pro+ image analysis software was used for the measurement of grain size of piezoelectric ceramics. XRD analysis at room temperature revealed that a structural transformation from tetragonal to rhombohedral with increasing ZrO2 content in the BT matrix. The scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to investigate the microstructures and surface-fracture morphologies of the sintered samples. The relative densities and open porosity were measured by the Archimedes' immersion method in distilled water.Öğe Resveratrol-Loaded Silver Nanoparticles as an Effective Strategy for Targeted Breast Cancer Therapy(Wiley-V C H Verlag Gmbh, 2024) Topcu, Ege; Hepokur, Ceylan; Kariper, I. Afsin; Oksuz, Kerim Emre; Yaylim, IlhanThe AgNPs-Rsvl complex was investigated for its anti-cancer effects on human breast cancer cell lines. The UV-vis spectrophotometer was used to perform synthesized AgNPs-Rsvl binding analyses. The size and morphology of the AgNPs were determined by field emission gun-transmission electron microscopy (FEG-TEM). The surface chemical signatures of AgNPs nanocomposites were assessed using FT-IR spectroscopy, and the zeta potential (zeta potential) of various AgNPs colloids was measured using the Zetasizer Nano ZS analyzer. Cell proliferation was analyzed using the XTT method and cell apoptosis was analyzed using the AnnexinV-fluorescein isothiocyanate (FITC)/PI method. The effects of resveratrol were evaluated on human breast cancer cell lines (MDA-MB-231 and MCF-7). As a result of flow cytometry, a decrease in viability was observed in the MDA-MB-231 cells, and an increase in early apoptotic, late apoptotic, and necrotic values was observed. Resveratrol arrests the cell cycle in the G0/G1 phase but when used with AgNPs, the cell cycle arrests at the S phase. The combination of resveratrol and AgNPs exhibited a cytotoxic effect on cancer cells, with MDA-MB-231 breast cancer cells being the most sensitive to AgNPs-Rsvl. Resveratrol and AgNPs arrested the cell cycle and increased apoptosis, indicating their potential use in breast cancer treatment.Öğe Sustainable Synthesis of Multifunctionalized Amoxicillin-Loaded Biopolymer Foams(Amer Chemical Soc, 2025) Oksuz, Kerim Emre; Arslan, SaynurThe development of biocompatible biopolymer foams loaded with antibiotics is crucial to advancing drug delivery systems in biomedical engineering. These materials offer controlled drug release and specialized functionalities for improved therapeutic outcomes. This study presents the development and characterization of antimicrobial polymeric biofoam materials loaded with the drug amoxicillin (AMX). The sustainable synthesis of these biopolymer foams involves a cost-effective, eco-friendly method that incorporates natural starch within poly(vinyl alcohol) (PVA) through an aldehyde cross-linking/stabilizing process. The highly porous structure of the biofoams enabled effective impregnation of the AMX drug using an innovative process involving ultrasonication and vacuum pressure to maximize efficiency and minimize biomaterial loss. The findings demonstrate the potential of these PVA/starch-based biofoams as versatile drug delivery systems with desirable physicochemical and biological characteristics. Detailed investigations were conducted to evaluate morphological features, chemical properties, swelling behavior, in vitro biodegradability, drug release profiles, cell culture, and antimicrobial activity tests of the prepared biofoam samples. Investigating the effect of controlled loading of AMX under laboratory conditions on its release profile and studying its biodegradation in various environments over time represent a critical aspect of this research. The optimal release profile under physiological conditions and the potent inhibition of bacterial growth against Escherichia coli and Staphylococcus aureus microorganisms by AMX-loaded biofoam materials highlight their potential for biomedical applications. These materials show promise for the in vivo administration and local treatment of bacterial infections.
