97 research outputs found
Nano-graphene oxide and vitamin D delivery
No full textOne of the Most Interesting and Recent Insights into Biomimetic Scaffold Nano-Biomaterial is Smart Scaffolding with Targeted Drug Delivery Ability. in Recent Decades, the Use of Graphene-Based Materials, Such as Nano-Graphene Oxide (NGO), as a Drug Carrier with Amphiphilic Properties, Has Attracted Considerable Attention of Scientists and Researchers in This Field. in Addition, One of the Important Global Problems is Increased Vitamin D Deficiency, Particularly in Pregnant and Postmenopausal Women. Therefore, in This Work, by Considering Hydrophobic Properties of Vitamin D, We Attempted to Examine its Loading and Release Both in the Presence of Surfactant and Surfactant-Free NGO-Aqueous Solution. at First, NGO Powder Was Synthesized by the Modified Hummer\u27s Method. after the Preparation of Vitamin D and Tween 80 (TW) Solution, They Were Added to NGO Aqueous Solution. Simultaneously, the Next Vitamin D and NGO Aqueous Solution Was Prepared in a Surfactant-Free Mode. in Order to Evaluate the Loading Content, Both Solutions Were Centrifuged, and their Supernatant Was Analyzed by UV-Visible Spectroscopy. Additionally, FTIR Spectroscopy Was Employed to Determine the TW 80 Effects on Vitamin D and NGO. the Results Have Shown that Vitamin D Loading in Surfactant-Free Solution Was Approximately 0% While in the Presence of TW 80 It Was 75.37% ± 4.12. Therefore, the Combination of Vitamin D, TW 80, and NGO Can Be a Suitable Candidate for Carrying Hydrophobic Drugs in Smart Scaffolding, Especially in Bone Tissue Engineering
Synthesis and Characterization of Hydroxyapatite Nanocrystalsvia Chemical Precipitation Technique: Synthesis and characterization of hydroxyapatite
No full textIn this study, hydroxyapatite (HA) nanocrystals have been synthesized via chemical precipitation technique. Diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials and sodium hydroxide solution was used as the agent for pH adjustment. The powder sample was evaluated by techniques such as scanning electron microscope, transmission electron microscope, Fourier transform infra-red spectroscopy, differential thermal analysis, thermal gravimetric analysis, X-ray diffraction, atomic absorption spectroscopy and EDTA titrationan alyses. According to the above-experimental results, it was found that hydroxyapatite nanocrystals can successfully be produced through wet precipitation method. The bulk Ca/Pmolar ratio of synthesized hydroxyapatite was determined as 1.71 that was higher than stoichiometric ratio (1.667) which is expected for a pure HAphase. Finally, transmission electron microscopic technique demonstrated that the crystallites of prepared powder were nanosized with a needle-like morphology
Bone tissue engineering electrospun scaffolds based on layered double hydroxides with the ability to release vitamin D3: Fabrication, characterization and in vitro study
No full textMechanical behavior of calcium sulfate scaffold prototypes built by solid free-form fabrication
No full textPurpose: This paper aims to investigate the mechanical behavior of three-dimensional (3D) calcium sulfate porous structures created by a powder-based 3D printer. The effects of the binder-jetting and powder-spreading orientations on the microstructure of the specimens are studied. A micromechanical finite element model is also examined to predict the properties of the porous structures under the load. Design/methodology/approach: The authors printed cylindrical porous and solid samples based on a predefined designed model to study the mechanical behavior of the prototypes. They investigated the effect of three main build bed orientations (x, y and z) on the mechanical behavior of solid and porous specimens fabricated in each direction then evaluated the micromechanical finite-element model for each direction. The strut fractures were analyzed by scanning electron microscopy, micro-computed tomography and the von Mises stress distribution. Findings: Results showed that the orientation of powder spreading and binder jetting substantially influenced the mechanical behavior of the 3D-printed prototypes. The samples that were fabricated parallel to the applied load had higher compressive strength compared with those printed perpendicular to the load. The results of the finite element analysis agreed with the results of the experimental mechanical testing. Research limitations/implications: The mechanical behavior was studied for the material and the 3D-printing machine used in this research. If one were to use another material formulation or machine, the printing parameters would have to be set accordingly. Practical implications: This work aimed to re-tune the control factors of an existing rapid prototyping process for the given machine. The authors achieved these goals without major changes in the already developed hardware and software architecture. Originality/value: The results can be used as guidelines to set the printing parameters and a model to predict the mechanical properties of 3D-printed objects for the development of patient- and site-specific scaffolds
The effects of preservation procedures on amniotic membrane’s ability to serve as a substrate for cultivation of endothelial cells
No full textCardiovascular 3D bioprinting: A review on cardiac tissue development
No full textCardiovascular diseases such as myocardial infarction account for millions of worldwide deaths annually. Cardiovascular tissues constitute a highly organized and complex three-dimensional (3D) structure that makes them hard to fabricate in a biomimetic manner by conventional scaffold fabrication methods. 3D bioprinting has been introduced as a novel cell-based method in the last two decades due to its ability to recapitulate cell density, multicellular architecture, physiochemical environment, and vascularization of biological constructs with accurate designs. This review article aims to provide a comprehensive outlook to obtain cardiovascular functional tissues from the engineering of bioinks comprising cells, hydrogels, and biofactors to bioprinting techniques and relevant biophysical stimulations responsible for maturation and tissue-level functions. Also, cardiac tissue 3D bioprinting investigations and further discussion over its challenges and perspectives are highlighted in this review article
Cumulative Particle size distribution of ZP150, Calcium Sulfate Semihydrate.
No full text<p>Cumulative Particle size distribution of ZP150, Calcium Sulfate Semihydrate.</p
Printed scaffolds with different layer thickness (a), printed samples in different orientation (b), μCT results: lateral view of 90° (c) and 180° (d), and a middle cross sectional view including: layer of powders (e), pores and struts (f), 3D printed specimen (g), scaffold designed using SolidWorks (h).
No full text<p>Printed scaffolds with different layer thickness (a), printed samples in different orientation (b), μCT results: lateral view of 90° (c) and 180° (d), and a middle cross sectional view including: layer of powders (e), pores and struts (f), 3D printed specimen (g), scaffold designed using SolidWorks (h).</p
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