SYNTHESIS AND CHARACTERIZATION OF BIOACTIVE GLASS/FORSTERITE NANOCOMPOSITES FOR BONE AND DENTAL IMPLANTS

In this research, bioactive glass (BG) of the type CaO–P2O5–SiO2 and nanocrystalline forsterite (NF) bioceramic were successfully synthesized via sol–gel processing method. Heat-treatment process was done to obtain phase-pure nanopowders. After characterization of each sample, the nanocomposite samples were prepared by cold pressing method and sintered at 1000°C. The samples were fully characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) analyses. The average nanocrystallite size was determined using the Debye-Scherrer’s formula 19.6 nm. The bioactivity was examined in vitro with respect to the ability of hydroxyapatite (HAp) layer to form on the surfaces as a result of contact with simulated body fluid (SBF). According to the obtained results, the prepared nanocomposite enhances the fracture toughness of the BG matrix without deteriorating its intrinsic properties as bioactivity

SYNTHESIS AND CHARACTERIZATION OF HYDROXYAPATITECALCIUM HYDROXIDE FOR DENTAL COMPOSITES

In this work hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. Calcium hydroxide forms in addition to hydroxyapatite in samples with calcium to phosphorus ratio more than the stoichiometric one (Ca/P = 1.67). The effect of changing the pH of the precipitation solution was investigated. Changing the pH of solution had no effect on the amount of compounds formed in the structure. In contrast, an increase in Ca/P ratio increases the total amount of calcium hydroxide which is suitable for dental composite application

Development of 3D PCL microsphere/TiO\u3csub\u3e2\u3c/sub\u3e nanotube composite scaffolds for bone tissue engineering

In this research, the three dimensional porous scaffolds made of a polycaprolactone (PCL) microsphere/TiO2 nanotube (TNT) composite was fabricated and evaluated for potential bone substitute applications. We used a microsphere sintering method to produce three dimensional PCL microsphere/TNT composite scaffolds. The mechanical properties of composite scaffolds were regulated by varying parameters, such as sintering time, microsphere diameter range size and PCL/TNT ratio. The obtained results ascertained that the PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min had the most optimal mechanical properties and an appropriate pore structure for bone tissue engineering applications. The average pore size and total porosity percentage increased after increasing the microsphere diameter range for PCL and PCL/TNT (0.5 wt%) scaffolds. The degradation rate was relatively high in PCL/TNT (0.5 wt%) composites compared to pure PCL when the samples were placed in the simulated body fluid (SBF) for 6 weeks. Also, the compressive strength and modulus of PCL and PCL/TNT (0.5 wt%) composite scaffolds decreased during the 6 weeks of storage in SBF. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and alkaline phosphates (ALP) activity results demonstrated that a generally increasing trend in cell viability was observed for PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min compared to the control group. Eventually, the quantitative RT-PCR data provided the evidence that the PCL scaffold containing TiO2 nanotube constitutes a good substrate for cell differentiation leading to ECM mineralization

Planning the priority of high tech industries based on SWARA-WASPAS methodology: The case of the nanotechnology industry in Iran

Decision-making and planning at the top level is highly complicated. One important duty of each government and of policy makers is planning at different levels for future problems. This research addresses such a concern. Planning for the future is the aim of this research. Moreover, the importance of the topic is discussed. The case study focused on is the nanotechnology industry and its development in Iran. Nanotechnology is one of the main and strategic industries in Iran. The important criteria for such a development are determined based on a literature review and the experiences from other countries. The different alternatives are selected based on the different applications of nanotechnology in other industries. The alternatives are: agriculture, transportation, construction, oil and gas, textile products, food industry, defence industry, health and medicine, nano electronics, nano energy and environment and water. The methodology employed is Multiple Criteria Decision Making (MCDM). In addition, SWARA-WASPAS is the hybrid MADM model employed in which SWARA is applied to evaluate the criteria and WASPAS is utilised to evaluate and rank the alternatives

Synthesis and characterization of electrospun polyvinyl alcohol nanofibrous scaffolds modified by blending with chitosan for neural tissue engineering

Among several attempts to integrate tissue engineering concepts into strategies to repair different parts of the human body, neuronal repair stands as a challenging area due to the complexity of the structure and function of the nervous system and the low efficiency of conventional repair approaches. Herein, electrospun polyvinyl alcohol (PVA)/chitosan nano-fibrous scaffolds have been synthesized with large pore sizes as potential matrices for nervous tissue engineering and repair. PVA fibers were modified through blending with chitosan and porosity of scaffolds was measured at various levels of their depth through an image analysis method. In addition, the structural, physicochemical, biodegradability, and swelling of the chitosan nanofibrous scaffolds were evaluated. The chitosan-containing scaffolds were used for in vitro cell culture in contact with PC12 nerve cells, and they were found to exhibit the most balanced properties to meet the basic required specifications for nerve cells. It could be concluded that addition of chitosan to the PVA scaffolds enhances viability and proliferation of nerve cells, which increases the biocompatibility of the scaffolds. In fact, addition of a small percentage of chitosan to the PVA scaffolds proved to be a promising approach for synthesis of a neural-friendly polymeric blend

Biological Response of Biphasic Hydroxyapatite/Tricalcium Phosphate Scaffolds Intended for Low Load-Bearing Orthopaedic Applications:

In this study, a calcium phosphate scaffold of hydroxyapatite (HAp) and dicalcium phosphate dihydrate (DCPD) for application in osteoconductive and osteoinductive scaffolds was synthesized and characterized. The important note is that the prepared composites converted to HAp/tricalcium phosphate (TCP) after heat-treatment. This class of composites is interesting because porous HAp/TCP generally degrade more rapid than HAp due to the increased resorption rate of TCP. According to the obtained results, the values of elastic modulus, compressive strength and density of the samples reduced with increasing the percentage of the DCPD phase. It is worth mentioning that the mechanical properties of the prepared samples were near the natural compact bone. The samples were examined in vitro to confirm the apatite forming ability of the composites. Also, in vivo examination in a rabbit model was employed. After fully observation it was concluded that new bone formed on the pore walls, as osteoids and osteoclasts were evident two months postoperatively. Based on the obtained results, the prepared scaffolds seem to be a promising biomaterial for low weight bearing orthopaedic applications

Effect of the Synthesis Parameters on the Properties of Biphasic Ca(OH) -HA Nanopowders for Tissue Engineering Applications: Nanopowders for tissue engineering

Nanocrystalline hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. Effects of precipitation temperature and different calcium to phosphate ratios (Ca/P) on the obtained powders were investigated. Characterization of the powders was performed using XRD and FTIR spectra, scanning electron microscopy, and transmission electron microscopy. Increase in precipitation temperature increases the size and crystallinity of obtained crystals. Samples with Ca/P ratios more than stoichiometric ratio (1.67) had calcium hydroxide in their structures which is suitable for dental applications. Lower precipitation temperatures lead to lower crystallinity which is ideal for dental applications due to an increase in calcium hydroxide release

An overview of the use of biomaterials, nanotechnology, and stem cells for detection and treatment of COVID-19:towards a framework to address future global pandemics

A novel SARS-like coronavirus (severe acute respiratory syndrome-related coronavirus-2, SARS-CoV-2) outbreak has recently become a worldwide pandemic. Researchers from various disciplinary backgrounds (social to natural science, health and medicine, etc.) have studied different aspects of the pandemic. The current situation has revealed how the ongoing development of nanotechnology and nanomedicine can accelerate the fight against the novel viruses. A comprehensive solution to this and future pandemic outbreaks includes preventing the spread of the virus through anti-viral personal protective equipment (PPE) and anti-viral surfaces, plus efforts to encourage behavior to minimize risks. Studies of previously introduced anti-viral biomaterials and their optimization to fight against SARS-CoV-2 is the foundation of most of the recent progress. The identification of non-symptomatic patients and symptomatic patients is vital. Reviewing published research highlights the pivotal roles of nanotechnology and biomaterials in the development and efficiency of detection techniques, e.g., by applying nanotechnology and nanomedicine as part of the road map in the treatment of coronavirus disease 2019 (COVID-19) patients. In this review, we discuss efforts to deploy nanotechnology, biomaterials, and stem cells in each step of the fight against SARS-CoV-2, which may provide a framework for future efforts in combating global pandemics