Preparation Of Magnetic Microspheres Research Articles

Chitosan-coated halloysite nanotube magnetic microspheres for carcinogenic colorectal hemorrhage and liver laceration in albino rats.

Carcinogenic colorectal hemorrhage can cause severe blood loss and longitudinal ulcer, which ultimately become fatal if left untreated. The present study was aimed to formulate targeted release gemcitabine (GC)-containing magnetic microspheres (MM) of halloysite nanotubes (MHMG), chitosan (MCMG), and their combination (MHCMG). The preparation of MM by magnetism was confirmed by vibrating sample magnetometry (VSM), the molecular arrangement of NH2, alumina, and silica groups was studied by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS), the hollow spherical nature of the proposed MM was observed by scanning electron microscopy (SEM), functional groups were characterized by Fourier transform infrared (FTIR) spectroscopy and thermochemical modification was studied by thermogravimetric analysis (TGA). In vitro thrombus formation showed a decreasing trend of hemostatic time for MMs in the order of MHMG3 < MCMG3 < MHCMG7, which was confirmed by whole blood clotting kinetics. Interestingly, rat tail amputation and liver laceration showed 3 folds increased clotting efficiency of optimized MHCMG7 compared to that of control. In vivo histopathological studies and cell viability assays confirmed the regeneration of epithelial cells. The negligible systemic toxicity of MHCMG7, more than 90% entrapment of GC and high % release in alkaline medium made the proposed MM an excellent candidate for the control of hemorrhage in colorectal cancer. Conclusively, the healing of muscularis and improved recovery of the colon from granulomas ultimately improved the therapeutic effects of GC-containing MMs. The combination of both HNT and CTS microspheres made them more targeted.

IN VITRO-IN VIVO CORRELATIONSHIP APPROACH OF THE PREPARED MAGNETIC MICROSPHERES OF CYTARABINE

Objective: The objective of this study was to study the in vitro-in vivo correlationship between the magnetic microspheres prepared by continuous solvent evaporation (CSE) method by 32 factorial designs.&#x0D; Methods: CSE technique was used in the preparation of magnetic microspheres. Drug used was cytarabine and mice were the animal model used to check the correlationship.&#x0D; Results: The profiles are nearly identical and reveal that drug absorption is rapid. The in vivo drug absorbed was found to be in concordance with the in vitro release as seen in the superimposable curves.&#x0D; Conclusion: Cytarabine effectively reduces the amount of drug released and consequently absorbed in vivo in the initial phase.

Preparation of Magnetic Polyglycidyl Methacrylate Microspheres

We present an approach of synthesizing magnetic polyglycidyl methacrylate (PGMA) microspheres by a simple method of dispersion polymerization. Water-based Magnetic fluids which have different surface properties disperse in reaction system. The magnetic microspheres are appropriate to construct liquid chip carriers. In this work, citric acid-modified and citric acid sodium-modified magnetic nanoparticles for the preparation of magnetic microspheres are investigated. SEM results indicated that the magnetic microspheres have an average diameter of 3.78 μm with excellent monodispersity (PDI 1.09). Magnetization curve of Fe3O4 nanoparticles using superconducting quantum magnetometer showed their good performance in magnetic response characteristics. Chemical structures and crystal form of magnetic Fe3O4 were characterized and analyzed using FT-IR and XRD methods.

Preparation of magnetic microspheres with thiol-containing polymer brushes and immobilization of gold nanoparticles in the brush layer

Narrow-disperse magnetic microspheres were prepared by alkaline coprecipitation of Fe 2+ and Fe 3+ ions within poly(acrylic acid–divinylbenzene) microspheres that were prepared by distillation–precipitation copolymerization. Magnetic microspheres with polymer brushes that contain epoxy groups were prepared by graft copolymerization of glycidyl methacrylate and glycerol monomethacrylate via atom transfer radical polymerization (ATRP) from the magnetic microsphere surfaces. Subsequently, magnetic microspheres with thiol-containing polymer brushes were prepared by treating the epoxy group-containing magnetic microspheres with sodium hydrosulfide. Gold nanoparticles were immobilized in the brush layer of the thiol-containing magnetic microspheres through Au–S coordination. The catalytic activity of the gold nanoparticle-immobilized magnetic microspheres was investigated using the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride as a model reaction. The catalyst could be reused for over 10 cycles without noticeable loss of catalytic activity.

A Novel Process to Prepare Magnetic Polymer Microspheres

Abstract A new process for preparation of magnetic microspheres was investigated. In this process, the formation and the encapsulation of magnetic nanoparticles were accomplished in one step. The magnetic polymer microspheres exhibited superparamagnetic property and had a spherical shape with a smooth surface. This method can be used to prepare inorganic and organic composite particle when the inorganic particles can be prepared by chemical coprecipitation reaction.