Magnetic Chitosan Nanocomposite Research Articles

Composite films based on chitosan and nanomagnetite

Magnetic chitosan nanocomposite films were prepared by a simple one-step method based on the in situ co-precipitation of nanomagnetite. Both plasticized and no-plasticized films were obtained and characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and mechanical (tensile) and dynamic mechanical characterization. Nanomagnetite particles formed inside chitosan films were spherical with diameters ranging from 5 to 13nm. The film surface and morphology and mechanical behavior were greatly affected by nanoparticles concentration, leading to increasing roughness, stiffness and fragility as the iron oxide content increases. The nanoparticles interact strongly with the chitosan matrix, as was corroborated by TGA, FTIR and DRX. Even though, particles retain their magnetic characteristics and thus, composites containing more than 2wt% NMP exhibit magnetic behavior.

Magnetic chitosan nanocomposite for hyperthermia therapy application: Preparation, characterization and in vitro experiments

Nanocrystals of magnetite (Fe3O4) were prepared by alkaline precipitation. The precursor used for synthesis was ferrous chloride only and the reaction was carried out in absence of any oxidant. The synthesized pure phase magnetic nanoparticles (MNPs) were coated with a biocompatible polymer, chitosan (CS). FTIR and TGA confirm coating of CS on MNPs. Both bare and coated MNPs (Fe3O4 and CS-Fe3O4) show particle size 21.8±5.3 and 15.1±5.0nm respectively. The magnetization values of both the MNPs are 51.68 and 49.96emu/g at room temperature respectively. Negligible Coercivity and Remenance values at room temperature imply superparamagnetic behavior of the MNPs. The MNPs are studied for their induction heating abilities at 167.6, 251.4 and 335.2Oe (equivalent to 13.3, 20.0 and 26.7kAm−1 respectively), in order to use them in magnetic fluid hyperthermia therapy. At 335.2Oe, CS coated nanoparticles (NPs) show maximum SAR of 118.85W/g, while bare NPs show SAR of 79.32W/g. Low cytotoxic effects of both the MNPs on L929 cell line proved their suitability for in vivo applications. NH2 group rendered by CS can further be used for conjugation of biomolecules to make them suitable candidates for biosensing and targeted drug delivery.

Magnetic Chitosan Nanocomposite Used as Cleanup Material to Detect Chloramphenicol in Milk by GC-MS

A novel method for determination of chloramphenicol in milk samples was introduced. Magnetic Fe3O4@chitosan nanocomposites were synthesized by adding chitosan to the surface of magnetic Fe3O4 using glutaraldehyde as cross-linker. Extraction with ethyl acetate, the study used the magnetic Fe3O4@CS as cleanup materials, without an additional cleanup step, to detect chloramphenicol in milk samples. To obtain maximal cleanup efficiency, several parameters were investigated including amount of magnetic materials, pH of the solution, purification time, and temperature. Under the optimal conditions (the amount of 100 mg/g of magnetic materials, pH = 5, 10 min, and 20 °C), the sensitivity of the proposed method had improved about tenfold than that of without magnetic materials. Moreover, the decision limits and detection capability were 0.05 and 0.11 μg/kg, respectively, which were comparable to those measured by most methods. The rapid, simple, solvent-saving, and efficient method was proved to be robust in monitoring [d(−)-theo-2-dichloroacetamido-1-p-nitrophenyl-1,3-propanediol] in milk samples.

Magnetic catechol-chitosan with bioinspired adhesive surface: preparation and immobilization of ω-transaminase.

The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS) - iron oxide nanoparticles (IONPs) composites carrying adhesive moieties with strong surface affinity. The ω-transaminase (ω-TA) was immobilized onto this magnetic composite via nucleophilic reactions between catechol and ω-TA. Under optimal conditions, 87.5% of the available ω-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that ω-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized ω-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4°C in phosphate buffered saline (PBS) for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized.

Preparation of Magnetic Chitosan Nanocomposite Particles and Their Susceptibility for Cellular Separation Applications

Preparation of Magnetic Chitosan Nanocomposite Particles and Their Susceptibility for Cellular Separation Applications

Magnetic Chitosan Nanocomposites: A Useful Recyclable Tool for Heavy Metal Ion Removal

Magnetic chitosan nanocomposites have been synthesized on the basis of amine-functionalized magnetite nanoparticles. These nanocomposites can be removed conveniently from water with the help of an external magnet because of their exceptional properties. The nanocomposites were applied to remove heavy metal ions from water because chitosan that is inactive on the surface of the magnetic nanoparticles is coordinated with them. The interaction between chitosan and heavy metal ions is reversible, which means that those ions can be removed from chitosan in weak acidic deionized water with the assistance of ultrasound radiation. On the basis of the reasons referred to above, synthesized magnetic chitosan nanocomposites were used as a useful recyclable tool for heavy metal ion removal. This work provides a potential platform for developing a unique route for heavy metal ion removal from wastewater.

Biomimetic Preparation of Magnetite/Chitosan Nanocomposite via In Situ Composite Method —– Potential Use in Magnetic Tissue Repair Domain

This study focused on the preparation of magnetic chitosan nanocomposite that has a potential application to bone repair and regeneration using an in situ composite method where chitosan membrans was used as the template and NaOH was used as the precipitant. X-ray diffraction analysis results show the formation of magnetite in the chitosan matrix. From the magnetic measurement, it could be concluded that the magnetic chitosan rods were superparamagnetic, and that this is the unique property of nanomagnetite. Macroscopical layer structure of the magnetic chitosan rods was observed from the photographs after mechanical test, and the microlayer structure of the rods was observed from the images of scanning electron microscopy. The mechanism for preparing the rods was discussed in detail. Transmission electron microscope was used to investigate the magnetite particles in the chitosan matrix and from the images it was concluded that the magnetite particles dispersed well in chitosan matrix with particle size of about 10 nm. The mechanical properties of the magnetic chitosan rods were measured and the blending strength was found to be 98.8 MPa. The mechanical properties did not decline when compared with those of the pure chitosan materials.