Browsing by Subject "Tissue Scaffolds"

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    Evaluation of borate bioactive glass scaffolds with different pore sizes in a rat subcutaneous implantation model
    (2014) Deliormanli A.M.; Liu X.; Rahaman M.N.
    Borate bioactive glass has been shown to convert faster and more completely to hydroxyapatite and enhance new bone formation in vivo when compared to silicate bioactive glass (such as 45S5 and 13-93 bioactive glass). In this work, the effects of the borate glass microstructure on its conversion to hydroxyapatite (HA) in vitro and its ability to support tissue ingrowth in a rat subcutaneous implantation model were investigated. Bioactive borate glass scaffolds, designated 13-93B3, with a grid-like microstructure and pore widths of 300, 600, and 900 μm were prepared by a robocasting technique. The scaffolds were implanted subcutaneously for 4 weeks in Sprague Dawley rats. Silicate 13-93 glass scaffolds with the same microstructure were used as the control. The conversion of the scaffolds to HA was studied as a function of immersion time in a simulated body fluid. Histology and scanning electron microscopy were used to evaluate conversion of the bioactive glass implants to hydroxyapatite, as well as tissue ingrowth and blood vessel formation in the implants. The pore size of the scaffolds was found to have little effect on tissue infiltration and angiogenesis after the 4-week implantation. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
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    Synthesis and characterization of cerium- and gallium-containing borate bioactive glass scaffolds for bone tissue engineering
    (Kluwer Academic Publishers, 2015) Deliormanlı A.M.
    Bioactive glasses are widely used in biomedical applications due to their ability to bond to bone and even to soft tissues. In this study, borate based (13-93B3) bioactive glass powders containing up to 5 wt% Ce2O3 and Ga2O3 were prepared by the melt quench technique. Cerium (Ce+3) and gallium (Ga+3) were chosen because of their low toxicity associated with bacteriostatic properties. Bioactive glass scaffolds were fabricated using the polymer foam replication method. In vitro degradation and bioactivity of the scaffolds were evaluated in SBF under static conditions. Results revealed that the cerium- and gallium-containing borate glasses have much lower degradation rates compared to the bare borate glass 13-93B3. In spite of the increased chemical durability, substituted glasses exhibited a good in vitro bioactive response except when the Ce2O3 content was 5 wt%. Taking into account the high in vitro hydroxyapatite forming ability, borate glass scaffolds containing Ce+3 and Ga+3 therapeutic ions are promising candidates for bone tissue engineering applications. © 2015, Springer Science+Business Media New York.
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    Electrically conductive borate-based bioactive glass scaffolds for bone tissue engineering applications
    (SAGE Publications Ltd, 2017) Turk M.; Deliormanll A.M.
    In this study, electrically conductive, borate-based, porous 13-93B3 bioactive glass composite scaffolds were prepared using a polymer foam replication technique. For this purpose, a slurry containing 40 vol% glass particles and 0-10 wt% graphene nanoplatelets was prepared by dispersing the particles in ethanol in the presence of ethyl cellulose. Composite scaffolds were subjected to a controlled heat treatment, in air atmosphere, to decompose the foam and sinter the glass particles into a dense network. It was found that the applied heat treatment did not influence the structure of graphene in the glass network. Graphene additions did not negatively affect the mechanical properties and enhanced the electrical conductivity of the glass scaffolds. In X-ray diffraction analysis, the crystalline peak corresponding to hydroxyapatite was observed in all the samples suggesting that all of the samples were bioactive after 30 days of immersion in simulated body fluid. However, Fourier transform infrared spectroscopy analysis and scanning electron microscope observations revealed that hydroxyapatite formation rate decreased with increasing graphene concentration especially for samples treated in simulated body fluid for shorter times. Based on the cytotoxicity assay findings, the MC3T3-E1 cell growth was significantly inhibited by the scaffolds containing higher amount of graphene compared to bare glass scaffolds. Best performance was obtained for 5 wt% graphene which yielded an enhancement of electrical conductivity with moderate cellular response and in vitro hydroxyapatite forming ability. The study revealed that the electrically conductive 13-93B3 graphene scaffolds are promising candidates for bone tissue engineering applications. © The Author(s) 2017.
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    13-93B3 Bioactive Glass: A New Scaffold for Transplantation of Stem Cell-Derived Chondrocytes
    (Lippincott Williams and Wilkins, 2018) Gunhan K.; Bariskan S.; Uz U.; Vatansever S.; Kivanc M.
    Research using animal models gives human trials hope for recovery in many fields of regenerative medicine, although they are sometimes poor predictors for human experiences. Our goal was to investigate whether rat chondrocytes, differentiated from adipose-derived stem cells, could be transplanted using a new, easily shaped, bioactive glass scaffold, and to show the immunohistochemical results. Intraperitoneal and retroperitoneal adipose tissue was extracted from 6 male Wistar albino type rats. The fatty tissue samples were fragmented and incubated. Chondrogenic differentiation was carried out and collagen type II, bFGF, and Sox-9 immunohistochemical characterization analysis was performed. Differentiated chondrocytes were implanted on 13-93B3 bioactive glass scaffolds and transplanted into the right ears of the rats. As control, only the biomaterial was transplanted into the left ears of the rats. After 1 month, the rats were sacrificed and transplantation areas were examined immunohistochemically. Histological examination of control samples from the left ears revealed that the biomaterial was covered with connective tissue, its general structure was preserved, and resorption of the scaffold had started. In specimens from the right ears, the biomaterial was covered with connective tissue, its structure was preserved, cartilage cells were present around the biomaterial, and the presence of cartilage tissue was demonstrated immunohistochemically. In conclusion, 13-93B3 bioactive glass scaffold contributed to the formation of new collagen and the survival of chondrocytes, and is a promising new biomaterial that will prove very useful in regenerative medicine. © Copyright 2017 by Mutaz B. Habal, MD.
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    Response of mouse bone marrow mesenchymal stem cells to graphene-containing grid-like bioactive glass scaffolds produced by robocasting
    (SAGE Publications Ltd, 2018) Deliormanlı A.M.; Türk M.; Atmaca H.
    In the study, three-dimensional, grid-like silicate-based bioactive glass scaffolds were manufactured using a robotic deposition technique. Inks were prepared by mixing 13-93 bioactive glass particles in Pluronic® F-127 solution. After deposition, scaffolds were dried at room temperature and sintered at 690°C for 1 h. The surface of the sintered scaffolds was coated with graphene nanopowder (1, 3, 5, 10 wt%) containing poly(ε-caprolactone) solution. The in vitro mineralization ability of the prepared composite scaffolds was investigated in simulated body fluid. The surface of the simulated body fluid-treated scaffolds was analyzed using scanning electron microscopy to investigate the hydroxyapatite formation. Mechanical properties were tested under compression. Results revealed that graphene coating has no detrimental effect on the hydroxyapatite forming ability of the prepared glass scaffolds. On the other hand, it decreased the compression strength of the scaffolds at high graphene concentrations. The prepared grid-like bioactive glass-based composite scaffolds did not show toxic response to bone marrow mesenchymal stem cells. It was shown that stem cells seeded onto the scaffolds attached and proliferated well on the surface. Cells seeded on the scaffolds surface also demonstrated osteogenic differentiation under in vitro conditions in the absence of transforming growth factors. © The Author(s) 2018.
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    Photostimulation of osteogenic differentiation on silk scaffolds by plasma arc light source
    (Springer London, 2018) Çakmak A.S.; Çakmak S.; Vatansever H.S.; Gümüşderelioğlu M.
    Low-level laser therapy (LLLT) has been used for more than 30 years to heal wounds. In recent years, LLLT or photostimulation has been indicated as an effective tool for regenerative and dental medicine by using monochromatic light. The aim of this study is to indicate the usability of plasma arc light source for bone regeneration. This is why we used polychromatic light source providing effective wavelengths in the range of 590–1500 nm for cellular response and investigated photostimulation effects on osteogenic differentiation of human mesenchymal stem cells (hMSCs) seeded on 3D silk scaffolds. Cellular responses were examined by using cell culture methods in terms of proliferation, differentiation, and morphological analyses. The results showed that photostimulation with a polychromatic light source (applied for 5 min from the 3rd day after seeding up to the 28th day in 2-day intervals with 92-mW/cm2 power from 10-cm distance to the cells) enhanced osteogenic differentiation of hMSCs according to higher alkaline phosphatase (ALP) activity, collagen and calcium content, osteogenic gene expressions, and matrix mineralization. In conclusion, we suggest that the plasma arc light source that was used here has a great potential for bone regeneration. © 2017, Springer-Verlag London Ltd., part of Springer Nature.
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    Novel simple strategy for cartilage tissue engineering using stem cells and synthetic polymer scaffold
    (Lippincott Williams and Wilkins, 2019) Uz U.; Gunhan K.; Vatansever S.; Kivanc M.; Yuceturk A.V.
    Cartilage created by tissue engineering is a promising new development in facial reconstructive surgery. The purpose of this study was to evaluate the histological results of implantation of synthetic polymer scaffold with chondrocytes differentiated from adipose-derived mesenchymal stem cells. Adipose tissue obtained from Wistar albino rats was dissociated, incubated and placed in culture medium. After a sufficient level of stem cell proliferation, the differentiation phase was started. Cells were collected on the 7th and 21st day of culture for chondrogenic characterization. After the 21st day of the differentiation phase of chondrocytes, they were transferred onto poly(dl-lactide-epsilon-caprolactone) synthetic polymer and culture continued for 24 hours. The scaffold with chondrocytes was then implanted into a subcutaneous area of skin on the back of the neck of the rat. Six weeks after implantation, all rats were sacrificed and the implantation areas were analyzed. Chondrocytes derived from adipogenic mesenchymal stem cells were stained positively with collagen II, aggrecan and Sox-9 after the differentiation stages. Histological examination of the excised material showed that chondrocytes were present, and the scaffold had been completely absorbed. The results of this study indicate that the differentiation method from mesenchymal stem cells to chondrogenic lineage was straightforward and scaffold with cells was easily accessible. This technique may be a good option for cartilage tissue engineering. © 2019 by Mutaz B. Habal, MD
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    Direct Write Assembly of Graphene/Poly(ε-Caprolactone) Composite Scaffolds and Evaluation of Their Biological Performance Using Mouse Bone Marrow Mesenchymal Stem Cells
    (Humana Press Inc., 2019) Deliormanlı A.M.
    Scaffold and mesenchymal stem cell–based cartilage tissue engineering offers a favorable way for the repair and regeneration of injured cartilage. In this study, poly (ε-caprolactone) PCL scaffolds with grid-like structure having periodic lattice was manufactured by robocasting method in the presence of graphene nanoplatelets for cartilage tissue engineering applications. For this purpose, a PCL solution (20 wt%) containing pristine graphene nanopowders in the form of platelets was prepared as printing ink and it was dispensed through a nozzle at room temperature to an ethanol bath at 4 °C. The construction of porous scaffolds was made by a layer-by-layer assembly. Results revealed that graphene additions were not detrimental to deposition process and the structure of the resultant scaffolds. In vitro cell tests indicated that the prepared grid-like graphene/PCL composite scaffolds have good cytocompatibility and non-toxicity for mouse bone marrow mesenchymal stem cells. The stem cells attached and proliferated well on the scaffolds and they also demonstrated a chondrogenic differentiation in the absence of transforming growth factors. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
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    Effect of polycaprolactone scaffolds containing different weights of graphene on healing in large osteochondral defect model
    (Taylor and Francis Ltd., 2022) Basal O.; Ozmen O.; Deliormanli A.M.
    Now it is possible to combine the different biomaterial properties of graphene and 3 D printing scaffolds produced by tissue engineering for cartilage repair. In the study graphene-containing (1, 3, 5, 10 wt%), porous and oriented poly-ε-caprolactone-based scaffolds were prepared by robocasting method to use in the regeneration of large osteochondral defects. The scaffolds were implanted into the full-thickness osteochondral defect in a rabbit model to evaluate the regeneration of the defect in vivo. For this purpose, twenty female New Zealand white rabbits were used and they were euthanized at 4 and 8 weeks of implantation. The reparative osteochondral tissues were harvested from rabbit distal femurs and then processed for gross appearance assessment, radiographic imaging, histopathological, histochemical and immunohistochemical examinations. Results revealed that graphene-containing graft materials caused significant amelioration at the defect areas. Graphene-containing graft materials improved the fibrous, chondroid and osseous tissue regeneration compared to the control group. The expressions of bone morphogenetic protein-2 (BMP-2), collagen-1 (col-1), vascular endothelial growth factor (VEGF) and alkaline phosphatase (ALP) expressions were more prominent in graphene-containing PCL implanted groups (p <.001). Picrosirrius red method was used for to evaluate connective and muscle tissues. Results also revealed that the ameliorative effect of graphene increased by the elevation in concentration. The most prominent healing was observed in 10 wt% graphene-containing PCL based composite scaffold implanted group. This study results showed that graphene-containing PCL scaffolds enhanced the healing significantly in large osteochondral defect areas compared to the control groups. © 2022 Informa UK Limited, trading as Taylor & Francis Group.
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    Design of chemobrionic and biochemobrionic scaffolds for bone tissue engineering
    (Nature Research, 2024) Aslanbay Guler B.; Morçimen Z.G.; Taşdemir Ş.; Demirel Z.; Turunç E.; Şendemir A.; Imamoglu E.
    Chemobrionic systems have attracted great attention in material science for development of novel biomimetic materials. This study aims to design a new bioactive material by integrating biosilica into chemobrionic structure, which will be called biochemobrionic, and to comparatively investigate the use of both chemobrionic and biochemobrionic materials as bone scaffolds. Biosilica, isolated from Amphora sp. diatom, was integrated into chemobrionic structure, and a comprehensive set of analysis was conducted to evaluate their morphological, chemical, mechanical, thermal, and biodegradation properties. Then, the effects of both scaffolds on cell biocompatibility and osteogenic differentiation capacity were assessed. Cells attached to the scaffolds, spread out, and covered the entire surface, indicating the absence of cytotoxicity. Biochemobrionic scaffold exhibited a higher level of mineralization and bone formation than the chemobrionic structure due to the osteogenic activity of biosilica. These results present a comprehensive and pioneering understanding of the potential of (bio)chemobrionics for bone regeneration. © The Author(s) 2024.