Synthesis of Core-Shell Magnetic Supramolecular Nanocatalysts based on Amino-Functionalized Calix[4]arenes for the Synthesis of 4H-Chromenes by Ultrasonic Waves

Magnetic xanthan gum-silk fibroin hydrogel: A nanocomposite for biological and hyperthermia applications

A magnetic xanthan hydrogel/silk fibroin nanobiocomposite (XG hydrogel/SF/Fe3O4) was designed, fabricated, and characterized using analyzing methods such as FT-IR, EDX, FE-SEM, XRD, TGA, and VSM to evaluate the exact structure of product nanobiocomposite. The FE-SEM images reveal the presence of spherical shapes exhibiting a narrow size range and homogeneous distribution, measuring between 30 and 35 nm in diameter. The VSM analysis demonstrates the superparamagnetic properties of the XG hydrogel/SF/Fe3O4 nanobiocomposite, exhibiting a magnetic saturation of 54 emu/g at room temperature. The biological response of the nanobiocomposite scaffolds was assessed through cell viability and red blood cell hemolytic assays. MCF10A cells were exposed to a concentration of 1.75 mg/mL of the nanobiocomposite, and after 2 and 3 days, the cell viability was found to be 96.95 % and 97.02 %, respectively. The hemolytic effect was nearly 0 % even at higher concentrations (2 mg/mL). Furthermore, the magnetic nanobiocomposite showed excellent potential for hyperthermia applications, with a maximum specific absorption rate of 7 W/g for 1 mg/mL of the sample under a magnetic field in different frequencies (100, 200, 300, and 400 MHz) and 5 to 20 min time intervals.

Utilizing magnetic xanthan gum nanocatalyst for the synthesis of acridindion derivatives via functionalized macrocycle Thiacalix[4]arene

An effective method for synthesizing acridinedione derivatives using a xanthan gum (XG), Thiacalix[4]arene (TC4A), and iron oxide nanoparticles (IONP) have been employed to construct a stable composition, which is named Thiacalix[4]arene-Xanthan Gum@ Iron Oxide Nanoparticles (TC4A-XG@IONP). The process used to fabricate this nanocatalyst includes the in-situ magnetization of XG, its amine modification by APTES to get NH2-XG@IONP hydrogel, the synthesis of TC4A, its functionalization with epichlorohydrine, and eventually its covalent attachment onto the NH2-XG@IONP hydrogel. The structure of the TC4A-XG@IONP was characterized by different analytical methods including Fourier-transform infrared spectroscopy, X-Ray diffraction analysis (XRD), Energy Dispersive X-Ray, Thermal Gravimetry analysis, Brunauer-Emmett-Teller, Field Emission Scanning Electron Microscope and Vibration Sample Magnetomete. With magnetic saturation of 9.10 emu g-1 and ~ 73% char yields, the TC4As-XG@IONP catalytic system demonstrated superparamagnetic property and high thermal stability. The magnetic properties of the TC4A-XG@IONP nanocatalyst system imparted by IONP enable it to be conveniently isolated from the reaction mixture by using an external magnet. In the XRD pattern of the TC4As-XG@IONP nanocatalyst, characteristic peaks were observed. This nanocatalyst is used as an eco-friendly, heterogeneous, and green magnetic catalyst in the synthesis of acridinedione derivatives through the one-pot pseudo-four component reaction of dimedone, various aromatic aldehydes, and ammonium acetate or aniline/substituted aniline. A combination of 10 mg of catalyst (TC4A-XG@IONP), 2 mmol of dimedone, and 1 mmol of aldehyde at 80 °C in a ethanol at 25 mL round bottom flask, the greatest output of acridinedione was 92% in 20 min.This can be attributed to using TC4A-XG@IONP catalyst with several merits as follows: high porosity (pore volume 0.038 cm3 g-1 and Pore size 9.309 nm), large surface area (17.306 m2 g-1), three dimensional structures, and many catalytic sites to active the reactants. Additionally, the presented catalyst could be reused at least four times (92-71%) with little activity loss, suggesting its excellent stability in this multicomponent reaction. Nanocatalysts based on natural biopolymers in combination with magnetic nanoparticles and macrocycles may open up new horizons for researchers in the field.

Fabrication and characterization of a novel catalyst based on modified zirconium metal-organic-framework for synthesis of polyhydroquinolines

A novel catalyst was fabricated in this study based on zirconium MOF modified with pyridine carboxaldehyde in a solvothermal reaction, embedded with cerium. In order to confirm the catalyst structure, various characterization techniques, including FTIR, Far IR, EDX, XRD, TGA, FE-SEM, ICP, and BET analyses, were employed. The results indicated that the UiO-66-Pyca-Ce (III) catalyst had a Langmuir surface area of 501.63 m2/g, a pore volume of 0.28 cm3/g, and a pore size of 2.27 nm. To study catalytic activity, a sequential approach of Knoevenagel condensation and Michael addition was used to synthesize various polyhydroquinoline derivatives. The reaction took place at ambient temperature. The UiO-66-Pyca-Ce (III) catalyst demonstrated high efficacy (90%) and reusability in asymmetric synthesis of polyhydroquinoline derivatives for several reasons, including the possession of three Lewis acid activation functions.

Synthesis of Fe3O4@SiO2@Pr-NH2@DAP as a magnetic recyclable nano-catalyst for efficient synthesis of pyranothiazolopyrimidines and 4H-pyrans under solvent-free condition

In this research, we describe the synthesis of silica-coated nano-Fe3O4 particles, which were successfully modified by diaminopyrimidine, and their physicochemical properties were characterized using FT-IR, XRD, TEM, FE-SEM, EDX, EDX-mapping, and TGA. The catalytic activity of this novel nano-catalyst was evaluated by three-component reactions for the preparation of pyranothiazolopyrimidines and 4H-pyrans under solvent-free conditions. Recyclability of the catalyst up to six consecutive rounds, atom economy, high yield and purity of desired products, and easy work-up method are some of the exciting features of this system that make it more favorable from a green chemistry point of view.

Recent advances on hyperthermia therapy applications of carbon-based nanocomposites

Generally, hyperthermia is referred to the composites capability to increase local temperature in such a way that the generated heat would lead to cancerous or bacteria cells destruction, with minimum damage to normal tissue cells. Many different materials have been utilized for hyperthermia application via different heat generating methods. Carbon-based nanomaterials consisting of graphene oxide (GO), carbon nanotube (CNT), carbon dot (CD) and carbon quantum dot (CQD), nanodiamond (ND), fullerene and carbon fiber (CF), have been studied significantly for different applications including hyperthermia due to their biocompatibility, biodegradability, chemical and physical stability, thermal and electrical conductivity and in some cases photothermal conversion. Therefore, in this comprehensive review, a structure-based view on carbon nanomaterials application in hyperthermia therapy of cancer and bacteria via various methods such as optical, magnetic, ultrasonic and radiofrequency-induced hyperthermia is presented.

A novel nanocomposite containing zinc ferrite nanoparticles embedded in carboxymethylcellulose hydrogel plus carbon nitride nanosheets with multifunctional bioactivity

A novel and biologically active nanobiocomposite is synthesized based on carbon nitride nanosheet (g-C3N4) based carboxymethylcellulose hydrogels with embedded zinc ferrite nanoparticles. Physical-chemical aspects, morphological properties, and their multifunctional biological properties have been considered in the process of evaluation of the synthesized structure. The hydrogels' compressive strength and compressive modulus are 1.98 ± 0.03 MPa and 3.46 ± 0.05 MPa, respectively. Regarding the biological response, it is shown that the nanobiocomposite is non-toxic and biocompatible, and hemocompatible (with Hu02 cells). In addition, the developed material offers a suitable antibacterial activity for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

Functionalization of magnetic nanoparticles by creatine as a novel and efficient catalyst for the green synthesis of 2-amino-4H-chromene derivatives

By employing the naturally-originated molecule of creatine, Fe₃O₄@SiO₂-creatine as an environmentally benign magnetic organometallic nanobiocatalyst was successfully prepared via a convenient and green route. Then to acquire an inclusive comprehension of different properties of the catalyst, it was studied by various characterization techniques such as FT‐IR, FE-SEM, TEM, EDX, XRD, and VSM analyses. It was found that the size distribution of nanoparticles was an average diameter size of 70 nm. To examine the catalytic activity, it was applied in sequential knoevenagel condensation-Michael addition room temperature reaction of dimedone, malononitrile, and different substituted aromatic aldehydes to produce a variety of 2-amino-tetrahydro-4H-chromene-3-carbonitrile derivatives in a single step. Among the multiple outstanding advantages that can be mentioned for this work, some of the most noticeable ones include: affording the products in short reaction times with high yields, operating the reaction at ambient conditions and ease of catalyst separation.

Magnetic graphene oxide-lignin nanobiocomposite: a novel, eco-friendly and stable nanostructure suitable for hyperthermia in cancer therapy

In this research, a novel magnetic nanobiocomposite was designed and synthesized in a mild condition, and its potential in an alternating magnetic field was evaluated for hyperthermia applications. For this purpose, in the first step, graphene oxide was functionalized with a natural lignin polymer using epichlorohydrin as the cross-linking agent. In the second step, the designed magnetic graphene oxide-lignin nanobiocomposite was fabricated by the in situ preparation of magnetic Fe3O4 nanoparticles in the presence of graphene oxide functionalized with lignin. The resultant magnetic nanobiocomposite possessed certain main properties, including stability and homogeneity in aqueous solutions, making it suitable for hyperthermia applications. The chemical and structural properties of the synthesized magnetic graphene oxide-lignin composite were characterized using FT-IR, EDX, FE-SEM, TEM, TG and VSM analyses. The saturation magnetization value of this magnetic nanocomposite was recorded as 17.2 emu g-1. Further, the maximum specific absorption rate was determined to be 121.22 W g-1. Given these results, this newly fabricated magnetic nanobiocomposite may achieve considerable performance under the alternating magnetic field in fluid hyperthermia therapy.

Greener organic synthetic methods: Sonochemistry and heterogeneous catalysis promoted multicomponent reactions

Ultrasound is an essential technique to improve organic synthesis from the point of view of green chemistry, as it can promote better yields and selectivities, in addition to shorter reaction times when compared to the conventional methods. Heterogeneous catalysis is another pillar of sustainable chemistry being the recycling and reuse of the catalysts one of its great advantage. In the other hand, multicomponent reactions provide the synthesis of structurally diverse compounds, in a one-pot fashion, without isolation and purification of intermediates. Thus, the combination of these protocols has proved to be a powerful tool to obtain biologically active organic compounds with lower costs, time and energy consumption. Herein, we provide a comprehensive overview of advances on methods of organic synthesis that have been reported over the past ten years with focus on ultrasound-assisted multicomponent reactions under heterogeneous catalysis. In particular, we present pharmacologically important N- and O-heterocyclic compounds, considering their synthetic methods using green solvents, and catalyst recycling.

Magnetic Copper Ferrite Nanoparticles Functionalized by Aromatic Polyamide Chains for Hyperthermia Applications

A new magnetic nanocomposite with a statistical star polymer structure was designed and synthesized. Nanocomposite fabrication is based on the polymerization of aromatic polyamide chains on the surface of functionalized magnetic copper ferrite nanoparticles (CuFe₂O₄ MNPs). This magnetic nanostructure was characterized by several analysis methods. All the analytical methods used, for instance, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetric, vibrating-sample magnetometer, and scanning electron microscopy (SEM), confirmed the formation of polyamide chains. The obtained images from SEM imaging showed a unique nanoflower morphology which was the proper orientation results of synthesized nanoplates. Finally, the magnetic nanostructure showed a good potential for hyperthermia applications, with a maximum specific absorption rate of 7 W/g for 1 mg/mL of the sample under a magnetic field in different frequencies (100, 200, 300, and 400 MHz) and 5 to 20 min time intervals.

Metal-based nanoparticles for bone tissue engineering

Tissue is vital to the organization of multicellular organisms, because it creates the different organs and provides the main scaffold for body shape. The quest for effective methods to allow tissue regeneration and create scaffolds for new tissue growth has intensified in recent years. Tissue engineering has recently used some promising alternatives to existing conventional scaffold materials, many of which have been derived from nanotechnology. One important example of these is metal nanoparticles. The purpose of this review is to cover novel tissue engineering methods, paying special attention to those based on the use of metal-based nanoparticles. The unique physiochemical properties of metal nanoparticles, such as antibacterial effects, shape memory phenomenon, low cytotoxicity, stimulation of the proliferation process, good mechanical and tensile strength, acceptable biocompatibility, significant osteogenic potential, and ability to regulate cell growth pathways, suggest that they can perform as novel types of scaffolds for bone tissue engineering. The basic principles of various nanoparticle-based composites and scaffolds are discussed in this review. The merits and demerits of these particles are critically discussed, and their importance in bone tissue engineering is highlighted.