Chemical Analysis of Hematite Ore Collected from Pokhari, Nawalparasi, Nepal.

Iron is the principal raw material for steel industries and Hematite is a principal ore of iron. Quantitative and qualitative estimation of iron in its ores is a crucial factor before its extraction. In this work, quantitative chemical analysis of iron was carried out from the collected seventy-two hematite samples from Pokhari, Nawalparasi. Sampling of the hematite ore was performed by channel sampling method. Chemical analysis was carried out by gravimetric, titrimetric, UV-Vis spectrophotometric and atomic absorption spectroscopic methods. The findings of different parameters in percentage areas follows: loss on ignition (1.76 ± 0.17), silica (47.06 ± 4.01), and iron (36.75 ± 2.50) by titrimetric analysis. Based on the chemical analysis, the Fe content in the collected hematite sample is in intermediate range. Thus, for the profitable iron extraction, other factors such as coverage of ores, extraction costs, and market value should be considered.

Electroconductive Polythiophene Nanocomposite Fibrous Scaffolds for Enhanced Osteogenic Differentiation via Electrical Stimulation.

Biophysical cues are key distinguishing characteristics that influence tissue development and regeneration, and significant efforts have been made to alter the cellular behavior by means of cell-substrate interactions and external stimuli. Electrically conductive nanofibers are capable of treating bone defects since they closely mimic the fibrillar architecture of the bone matrix and deliver the endogenous and exogenous electric fields required to direct cell activities. Nevertheless, previous studies on conductive polymer-based scaffolds have been limited to polypyrrole, polyaniline, and poly(3,4-ethylenedioxythiophene) (PEDOT). In the present study, chemically synthesized polythiophene nanoparticles (PTh NPs) are incorporated into polycaprolactone (PCL) nanofibers, and subsequent changes in physicochemical, mechanical, and electrical properties are observed in a concentration-dependent manner. In murine preosteoblasts (MC3T3-E1), we examine how substrate properties modified by adding PTh NPs contribute to changes in the cellular behavior, including viability, proliferation, differentiation, and mineralization. Additionally, we determine that external electrical stimulation (ES) mediated by PTh NPs positively affects such osteogenic responses. Together, our results provide insights into polythiophene's potential as an electroconductive composite scaffold material.

Recent Progress in Metal-Organic Framework-Derived Nanostructures in the Removal of Volatile Organic Compounds.

Air is the most crucial and life-supporting input from nature to the living beings of the planet. The composition and quality of air significantly affects human health, either directly or indirectly. The presence of some industrially released gases, small particles of anthropogenic origin, and the deviation from the normal composition of air from the natural condition causes air pollution. Volatile organic compounds (VOCs) are common contaminants found as indoor as well as outdoor pollutants. Such pollutants represent acute or chronic health hazards to the human physiological system. In the environment, such polluted gases may cause chemical or photochemical smog, leading to detrimental effects such as acid rain, global warming, and environmental pollution through different routes. Ultimately, this will propagate into the food web and affect the ecosystem. In this context, the efficient removal of volatile organic compounds (VOCs) from the environment remains a major threat globally, yet satisfactory strategies and auxiliary materials are far from being in place. Metal-organic frameworks (MOFs) are known as an advanced class of porous coordination polymers, a smart material constructed from the covalently bonded and highly ordered arrangements of metal nodes and polyfunctional organic linkers with an organic-inorganic hybrid nature, high porosities and surface areas, abundant metal/organic species, large pore volumes, and elegant tunability of structures and compositions, making them ideal candidates for the removal of unwanted VOCs from air. This review summarizes the fundamentals of MOFs and VOCs with recent research progress on MOF-derived nanostructures/porous materials and their composites for the efficient removal of VOCs in the air, the remaining challenges, and some prospective for future efforts.

NIR-Triggered Hyperthermal Effect of Polythiophene Nanoparticles Synthesized by Surfactant-Free Oxidative Polymerization Method on Colorectal Carcinoma Cells.

In this work, polythiophene nanoparticles (PTh-NPs) were synthesized by a surfactant-free oxidative chemical polymerization method at 60 °C, using ammonium persulphate as an oxidant. Various physicochemical properties were studied in terms of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, and differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA). Photothermal performance of the as-synthesized PTh-NPs was studied by irradiating near infra-red of 808 nm under different concentration of the substrate and power supply. The photothermal stability of PTh-NPs was also studied. Photothermal effects of the as-synthesized PTh-NPs on colorectal cancer cells (CT-26) were studied at 100 µg/mL concentration and 808 nm NIR irradiation of 2.0 W/cm2 power. Our in vitro results showed remarkable NIR laser-triggered photothermal apoptotic cell death by PTh-NPs. Based on the experimental findings, it is revealed that PTh-NPs can act as a heat mediator and can be an alternative material for photothermal therapy in cancer treatment.

In-situ polymerized polypyrrole nanoparticles immobilized poly(ε-caprolactone) electrospun conductive scaffolds for bone tissue engineering.

Despite intensive attempts to fabricate polypyrrole nanoparticles (PPy-NPs) incorporated nanofibrous scaffolds, a low-cost facile strategy is still demanded. Herein, we developed a novel strategy- in-situ polymerization of PPy-NPs and immobilized them into the PCL polymeric matrix in a single step. For the in-situ polymerization of PPy-NPs, ferric chloride hexahydrate (FeCl3.6H2O) was introduced as an oxidant into the blended solution of PCL and pyrrole monomers. Due to the chemical oxidative polymerization process, the clear solution changed into a black PCL/PPy solution. After electrospinning the solution, PCL/PPy composite nanofibers were fabricated. The immobilization of PPy-NPs into PCL matrix was clearly revealed by Bio-TEM images. The Field emission scanning electron microscopy (FESEM) results exhibited that the PCL/PPy scaffolds showed significantly decreased fiber diameter. The atomic force microscopy (AFM) study showed increased surface roughness in the PCL/PPy scaffolds. The mechanical strength test of PCL/PPy scaffolds showed improved Young's Modulus (YM = 2 to 4-folds) and tensile strength (TS = 3 to 4-folds). As well as the YM and TS were gradually increased with increased concentration of PPy-NPs in composite scaffolds. The conductivity measurement conducted on polymeric solution and electrospun scaffolds showed an increasing trend of conductive property in the PCL/PPy solution and scaffolds too. The surface wettability test exhibited decreased water contact angle measurement from 126° for pure PCL to 93° for the PCL/PPy-200 composite scaffold. The biomineralization test conducted by simulated body fluid (SBF) incubation showed enhanced calcium-phosphate crystal deposition on the PCL/PPy scaffolds. The CCK-8 assay and confocal laser scanning microscopic (CLSM) imaging conducted without and with electrical stimulation (ES) displayed enhanced cell adhesion, growth, and proliferation of MC3T3-E1 cells on the PCL/PPy conductive scaffolds. Furthermore, ALP and ARS staining assays showed significant enhancement of the calcium-phosphate deposition on the PCL/PPy scaffolds after ES treatment. Hence, the current study provides a novel strategy for the fabrication of PCL/PPy conductive scaffolds with enhanced bioactivity, biocompatibility, and osteogenic differentiation under electrical stimulation confirmed its promising application towards bone tissue engineering.

Polyaniline-coated titanium oxide nanoparticles and simvastatin-loaded poly(ε-caprolactone) composite nanofibers scaffold for bone tissue regeneration application.

Poly(ε-caprolactone) (PCL) nanofibers loaded with polyaniline coated titanium oxide nanoparticles (TiO2/PANI) and simvastatin (SIM) drug were produced by the electrospinning method. As-prepared samples were investigated in terms of morphology characterization, mechanical properties, physiochemical properties, drug release, biomimetic mineralization, and biocompatibility. in vitro drug release studies were conducted in the phosphate buffer saline (PBS) at pH 7.4. The results suggest that varying the concentrations of TiO2/PANI nanoparticles could change the rate of drug release. The release mechanism was studied using several kinetic models, including the Higuchi model, the Hixson-Crowell model, and the Korsmeyer-Peppas model, to clarify the mechanism of SIM release from the composite nanofibers. The assessment of in vitro mineralization of the composite nanofibers for the growth of hydroxyapatite was performed in simulated body fluid (SBF). Field scanning electron microscopy (FE-SEM) imagery and energy-dispersive X-ray spectroscopy (EDS) analyses indicated that after soaking in SBF, a hydroxyapatite layer was formed on the surface of the nanofibrous webs. These novel composite nanofibers release simvastatin in a controlled manner with profound cell proliferation and attachment compared to that in pure PCL nanofiber, which indicates their potential for bone regeneration applications.

Synthesis of polypyrrole nanorods via sacrificial removal of aluminum oxide nanopore template: A study on cell viability, electrical stimulation and neuronal differentiation of PC12 cells.

Synthesis of nanomaterials having uniform shape and size is a challenging task. Properties exhibited by such substrates would be compatible and homogeneous compared to the average properties displayed by those substrates with heterogeneous size. Herein, we report the synthesis of polypyrrole nanorods (PPy-NRs) of almost uniform size via oxidative chemical polymerization of pyrrole within anodized aluminum oxide nanopores followed by sacrificial removal of the template. Field emission scanning electron microscopy (FE-SEM), fourier transformed infra-red (FT-IR) spectra, X-ray diffraction (XRD), and ultra-violet-visible-near infra-red (UV-Vis-NIR) spectra of the substrate were used to analyze the physicochemical properties of as-synthesized PPy-NRs. PPy-NRs treated MC3T3-E1 and PC12 cells exhibited good biocompatibility in CCK-8 and live/dead assays. The assay showed more cell viability on PC12 cell lines. Electrical stimulation through PPy-NRs treated PC12 cells accelerated neuronal differentiation compared to those without electrical stimulation during in vitro cell culture.

Polydopamine-based Implantable Multifunctional Nanocarpet for Highly Efficient Photothermal-chemo Therapy.

We report a design and fabricate multifunctional localized platform for cancer therapy. Multiple stimuli-responsive polydopamine (PDA) was used for surface modification of electrospun doxorubicin hydrochloride (DOX) loaded polycaprolactone (PCL) fibers to make a designated platform. Photothermal properties such as photothermal performance and stability of the resulting composite mats were studied under the irradiation of the near-infrared (NIR) laser of 808 nm. With the incorporation of PDA into the fiber, a remarkable increase of local temperature was recorded under NIR illumination in a concentration-dependent manner with excellent stability. Drug released assay results revealed PDA coated PCL-DOX mats showed pH and NIR dual responsive behavior thereby exhibiting improved drug release in an acidic medium compared to physiological pH condition (pH 7.4) which is further increased by NIR exposure. The cancer activity in vitro of the mats was evaluated using cell counting (CCK) and live and dead cell assays. The combined effect of NIR mediated hyperthermia and chemo release resulting improved cells death has been reported. In summary, this study presents a major step forward towards a therapeutic model to cancer treatment utilizing pH and NIR dual responsive property from PDA alone in a fibrous mat.

Sacrificial template-based synthetic approach of polypyrrole hollow fibers for photothermal therapy.

In the present work, polypyrrole hollow fibers (PPy-HFs) were fabricated by sacrificial removal of soft templates of electrospun polycaprolactone (PCL) fibers with polypyrrole (PPy) coating through chemical polymerization of pyrrole monomer. Different physicochemical properties of as-fabricated PPy-HFs were then studied by Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, Differential scanning calorimetry/Thermogravimetric analysis (DSC/TGA), and X-ray photoelectron spectroscopy (XPS). The photothermal activity of PPy-HF was studied by irradiating 808-nm near infra-red (NIR) light under different power values with various concentrations of PPy-HFs dispersed in phosphate buffer solution (PBS, pH 7.4). These PPy-HFs exhibited enhanced photothermal performance compared with polypyrrole nanoparticles (PPy-NPs). Furthermore, these PPy-HFs showed photothermal effect that was laser-power- and concentration-dependent. The photothermal toxicity of the resulting nanofiber was evaluated using cell counting kit-8 (CCK-8) and live and dead cell assays. Results showed that these PPy-HFs were more effective in killing cancer cells under NIR irradiation. In contrast, hollow-fiber showed no cytotoxicity without NIR exposure. Among different nanofiber formulations, PPy-160 exhibited the highest photothermal toxicity. It could be explained by its enhanced photothermal performance compared to other specimens. The resulting PPy-HFs showed superior drug-loading capacity to PPy-NPs. This might be attributed to adequate binding of the drug into both luminal and abluminal hollow-fiber surfaces. Fabrication of this substrate type opens a promising new avenue for architectural design of biocompatible organic polymer for biomedical field.

A Review on Properties of Natural and Synthetic Based Electrospun Fibrous Materials for Bone Tissue Engineering.

Bone tissue engineering is an interdisciplinary field where the principles of engineering are applied on bone-related biochemical reactions. Scaffolds, cells, growth factors, and their interrelation in microenvironment are the major concerns in bone tissue engineering. Among many alternatives, electrospinning is a promising and versatile technique that is used to fabricate polymer fibrous scaffolds for bone tissue engineering applications. Copolymerization and polymer blending is a promising strategic way in purpose of getting synergistic and additive effect achieved from either polymer. In this review, we summarize the basic chemistry of bone, principle of electrospinning, and polymers that are used in bone tissue engineering. Particular attention will be given on biomechanical properties and biological activities of these electrospun fibers. This review will cover the fundamental basis of cell adhesion, differentiation, and proliferation of the electrospun fibers in bone tissue scaffolds. In the last section, we offer the current development and future perspectives on the use of electrospun mats in bone tissue engineering.