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Öğe Cellulose acetate-gelatin-coated boron-bioactive glass biocomposite scaffolds for bone tissue engineering(Iop Publishing Ltd, 2020) Rad, Reza Moonesi; Alshemary, Ammar Z.; Evis, Zafer; Keskin, Dilek; Tezcaner, AysenIn this study, we aimed to prepare and characterize porous scaffolds composed of pure and boron oxide (B2O3)-doped bioactive glass (BG) that were infiltrated by cellulose acetate-gelatin (CA-GE) polymer solution for bone tissue engineering applications. Composite scaffolds were cross-linked with glutaraldehyde after polymer coating to protect the structural integrity of the polymeric-coated scaffolds. The impact of B(2)O(3)incorporation into BG-polymer porous scaffolds on the cross-sectional morphology, porosity, mechanical properties, degradation and bioactivity of the scaffolds was investigated. Human dental pulp stem cells (hDPSCs) were enzymatically isolated and used for cell culture studies. According to scanning electron microscope analysis, the porous structure of the scaffolds was preserved after polymer coating. After polymer infiltration, the porosity of the scaffolds decreased from 64.2% to 59.35% for pure BG scaffolds and from 67.3% to 58.9% for B2O3-doped scaffolds. Meanwhile, their compressive strengths increased from 0.13 to 0.57 MPa and from 0.20 to 0.82 MPa, respectively. After polymer infiltration, 7% B2O3-incorporated BG scaffolds had higher weight loss and Ca-P layer deposition than pure BG scaffolds, after 14 d of incubation in simulated body fluid at 37 degrees C. Higher attachment and proliferation of hDPSCs were observed on 7% B2O3-BG-CA/GE scaffolds. In addition, the alkaline phosphatase activity of the cells was about 1.25-fold higher in this group than that observed on BG-CA/GE scaffolds after 14 d of incubation in osteogenic medium, while their intracellular calcium amounts were 1.7-fold higher than observed on BG-CA/GE after 7 d of incubation in osteogenic medium. Our results suggested that porous cellulose acetate-gelatin-coated boron-BG scaffolds hold promise for bone tissue engineering applications.Öğe Lanthanum doped dicalcium phosphate bone cements for potential use as filler for bone defects(Elsevier, 2021) Motameni, Ali; Alshemary, Ammar Z.; Dalgic, Ali Deniz; Keskin, Dilek; Evis, ZaferThe bone defects arising as a result of trauma should be filled to provide a framework to support and encourage the growth of new and living bone tissues. Among the many synthetic bone graft substitutes, self-hardening calcium phosphate (CP) cements have been widely used to repair hard tissue defects. In this study, pure dical-cium phosphate (DCP) and lanthanum (La) modified dicalcium phosphate (La-DCP) bone cements were prepared based on acid/base reaction between beta-tricalcium phosphate (beta TCP) (or La-beta TCP) and monocalcium phosphate monohydrate (MCPM) in the presence of water. The prepared bone cements were characterized using XRD, FTIR and SEM techniques to verify both La doping and to explore the alterations in the structural and molecular properties upon doping. With minimum addition of La3+ ions (0.090 mol), the pure phase of brushite trans-formed into monetite and the plate-like crystals of brushite turned into spheroid particles. The setting times of DCP bone cement declined gradually upon boosting amount of La3+ ions in DCP lattice. As the La amount in DCP cements rose from 0 to 0.225 mol, the compressive strength also increased from 7.90 +/- 0.8 to 9.64 +/- 1.47 MPa. The dissolution rate of DCP cements improved with addition of La3+ ions. Adsorption/desorption of Fetal bovine serum (FBS) on/from the prepared DCP bone cements showed higher protein loading of La-DCP cements than pure DCP. In vitro experiments on proliferation, adhesion, and osteogenic differentiation of Sarcoma osteogenic (Saos-2) cells indicated that addition 0.225 mol of La3+ ions promoted these properties compared to pure DCP. Results suggested that La3+ (0.225 mol) incorporated DCP bone cement (2La-DCP) has a potential to be used as a bone filler material.Öğe Nanocrystalline Zn2+ and SO42- binary doped fluorohydroxyapatite: A novel biomaterial with enhanced osteoconductive and osteoinconductive properties(Elsevier, 2019) Alshemary, Ammar Z.; Pazarceviren, Engin Ahmet; Dalgic, Ali Deniz; Tezcaner, Amen; Keskin, Dilek; Evis, ZaferIn this study, we have successfully doped hydroxyapatite (HA) with zinc (Zn2+), sulphate (SO42-) and fluoride (F-) ions to develop a new composition of bioceramic, Ca10-xZnx(PO4)(6-y)(SO4)(y)(OH)(2-z-y)F-z(SO4)(y), (x = 0, 0.2, 0.6, 1.0, y = 0, 0.5 and z = 0,1.0 mol), using wet precipitation method. The obtained materials were analysed using XRD, FTIR, FESEM, and XPS techniques to investigate the phase purity, particle morphology and elemental composition, respectively. A model anticancer drug (Doxorubicin, DOX) was loaded onto the surface of the Zn/SO4-FHA materials. About 100% loading of DOX with a controlled release profile was obtained. Degradation of materials in Simulated body fluid (SBF) was greatly improved with the incorporation of Zn2+/SO42- ions in comparison to HA/FHA, which makes it highly bioactive materials. In vitro cell viability and adhesion of Human fetal osteoblast (hFOB) cell were investigated. Cell viability has demonstrated that the hFOB cells proliferated at a high rate on Zn/SO4-FHA materials, confirming the in vitro biocompatibility of the materials. Alkaline phosphatase (ALP) activity and intracellular calcium deposition of hFOB cells seeded on 1ZnSO(4)-FHA disc surface was statistically higher than observed on pure HA and FHA discs, indicating that hFOB cells differentiated into mature osteoblasts on 1Zn/SO4-FHA disc surfaces. Taken together, our results suggest that HA substituted by (Zn2+, 0.2 mol), (SO42-, 0.5 mol) and (F-, 1 mol) (1Zn/So(4)-FHA) material was a promising material for hard tissue scaffolds.Öğe Porous clinoptilolite-nano biphasic calcium phosphate scaffolds loaded with human dental pulp stem cells for load bearing orthopedic applications(Iop Publishing Ltd, 2019) Alshemary, Ammar Z.; Pazarceviren, Ahmet Engin; Keskin, Dilek; Tezcaner, Aysen; Hussain, Rafaqat; Evis, ZaferClinoptilolite (Cpt)-nanohydroxyapatite (HA) (Cpt-HA) scaffolds were fabricated as a potential material for load bearing orthopaedic applications. Cpt-HA materials were successfully synthesized by using microwave assisted reflux method followed by the fabrication of three-dimensional (3D) porous scaffold via thermal decomposition process using polyethylene glycol (PEG)/polyvinyl alcohol (PVA) as porogens. The scaffold materials were characterized using x-ray diffraction, Fourier transform Infra-red, Scanning electron microscopy and Energy dispersive spectroscopy techniques. Incorporation of Cpt in HA scaffold significantly increased the compressive strength and surface hardness while scaffolds retained an interconnected porous structure with 64% porosity. Human dental pulp stem cells (DPSCs) were isolated from the third molar and used as pluripotent-like cell model to evaluate the biological properties of Cpt-HA scaffolds. Highest cellular attachment and proliferation were observed for DPSCs seeded on 2.0 g Cpt-HA scaffolds compare to pure HA. Similarly, significantly higher ALP activity of cells was observed on Cpt-HA scaffolds compared to pure HA. The enhanced proliferation and osteogenic response of the DPSCs cultured on Cpt-HA scaffolds suggest that the fabricated scaffolds can be used in bone tissue engineering. In this work, we have successfully shown that the interconnected porous Cpt-HA scaffolds have superior mechanical biological properties compared to pure HA scaffold.Öğe Silicate-doped nano-hydroxyapatite/graphene oxide composite reinforced fibrous scaffolds for bone tissue engineering(Sage Publications Ltd, 2018) Dalgic, Ali Deniz; Alshemary, Ammar Z.; Tezcaner, Aysen; Keskin, Dilek; Evis, ZaferIn this study, novel graphene oxide-incorporated silicate-doped nano-hydroxyapatite composites were prepared and their potential use for bone tissue engineering was investigated by developing an electrospun poly(epsilon-caprolactone) scaffold. Nanocomposite groups were synthesized to have two different ratios of graphene oxide (2 and 4 wt%) to evaluate the effect of graphene oxide incorporation and groups with different silicate-doped nano-hydroxyapatite content was prepared to investigate optimum concentrations of both silicate-doped nano-hydroxyapatite and graphene oxide. Three-dimensional poly(epsilon-caprolactone) scaffolds were prepared by wet electrospinning and reinforced with silicate-doped nano-hydroxyapatite/graphene oxide nanocomposite groups to improve bone regeneration potency. Microstructural and chemical characteristics of the scaffolds were investigated by X-ray diffraction, Fourier transform infrared spectroscope and scanning electron microscopy techniques. Protein adsorption and desorption on material surfaces were studied using fetal bovine serum. Presence of graphene oxide in the scaffold, dramatically increased the protein adsorption with decreased desorption. In vitro biocompatibility studies were conducted using human osteosarcoma cell line (Saos-2). Electrospun scaffold group that was prepared with effective concentrations of silicate-doped nano-hydroxyapatite and graphene oxide particles (poly(epsilon-caprolactone) - 10% silicate-doped nano-hydroxyapatite - 4% graphene oxide) showed improved adhesion, spreading, proliferation and alkaline phosphatase activity compared to other scaffold groups.Öğe Structural and Biological Analysis of Mesoporous Lanthanum Doped ?TCP For Potential Use as Bone Graft Material(Elsevier, 2020) Motameni, Ali; Dalgic, Ali Deniz; Alshemary, Ammar Z.; Keskin, Dilek; Evis, ZaferIn this study, mesoporous particles of beta-tricalcium phosphate (beta TCP, beta Ca-3(PO4)(2)) and lanthanum (La) doped beta TCP were synthesized using wet precipitation method attached with microwave refluxing system. The obtained materials were characterized and analysed using different sort of techniques such; X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Inductively coupled plasma optical emission spectroscopy (ICP-OES), Brunauer-Emmett-Teller (BET) and helium pycnometer. With incorporation of La3+ ions, relevant expansion in lattice parameters of beta TCP crystal was observed along with inhibition growth rate was observed. beta TCP and La-beta TCP materials were mesoporous in nature, pore diameter and pore volume were expanded with incorporation of La3+ ions. The loading/release on beta TCP and La-beta TCP particles surfaces were evaluated using fetal bovine serum (FBS) proteins. In vitro cell culture studies were performed with human osteosarcoma cell line (Saos-2). The outcomes approved that all La-beta TCP materials were cytocompatible and strict dose dependent effect of La3+ ions was observed on cell viability and alkaline phosphatase (ALP) activity. These results strongly suggest that La-beta TCP materials have a potential application in bone tissue engineering.Öğe Structural and biological assessment of boron doped bioactive glass nanoparticles for dental tissue application (vol 44, pg 9854, 2018)(Elsevier Sci Ltd, 2018) Rad, Reza Moonesi; Alshemary, Ammar Z.; Evis, Zafer; Keskin, Dilek; Altunbas, Korhan; Tezcaner, Aysen[No abstract available]Öğe Structural and biological assessment of boron doped bioactive glass nanoparticles for dental tissue applications(Elsevier Sci Ltd, 2018) Rad, Rezai Moonesi; Alshemary, Ammar Z.; Evis, Zafer; Keskin, Dilek; Altunbas, Korhan; Tezcaner, AysenIn this article, bioactive glass nanoparticles (BG-NPs) doped with boron were synthesized and characterized to evaluate their effects on human dental pulp stem cells (hDPSCs). All synthesized BGs were nano-sized and amorphous in nature. They showed the expected characteristic functional groups and composition close to the designed ones by microstructural characterizations. Porositimetry analysis revealed that increase of boron in the BG composition caused a decrease in the specific surface area, average pore diameter and total pore volume of NPs. hDPSCs were isolated from third molar teeth of patients and were shown to have the characteristics of mesenchymal stem cells. Dose dependent cytotoxicity study of boron doped BG-NPs suggested that 6.25 mg/ml was the optimum concentration for cells. ALP activity tests and intracellular calcium measurements revealed enhanced early stage odontogenic differentiation of hDPSCs treated with 6.25 mg/ml of different BG groups. Immunocytochemical staining showed positive effect of boron doped BG-NPs on DSPP, osteopontin and collagen I markers expression of hDPSCs. Our results indicated that boron doped BG-NPs hold potential as biomaterial in regenerative dentistry.
