Nanostructured magnetic alginate composites for biomedical applications

Abstract

This is a study of the preparation and characterization of polymeric-magnetic nanoparticles. The nanoparticles used were magnetite (Fe 3 O 4) and the chosen polymers were alginate and chitosan. Two types of samples were prepared: uncoated magnetic nanoparticles and magnetic nanoparticles encapsulated in polymeric matrix. The samples were analyzed by XRD, light scattering techniques, TEM, and magnetic SQUID. The XRD patterns identified magnetite (Fe 3 O 4) as the only crystalline phase. TEM analyses showed particle sizes between 10 and 20nm for magnetite, and 15 and 30nm for the encapsulated magnetite. The values of magnetization ranged from 75 to 100emu/g for magnetite nanoparticles, and 8 to 12emu/g for coated with chitosan, at different temperatures of 20K and 300K. The saturation of both samples was in the range of 49 to 50KOe. Variations of results between the two kinds of samples were attributed to the encapsulation of magnetic nanoparticles by the polymers.

Polydopamine functionalized hydrogel beads as magnetically separable antibacterial materials

“…The increased size in aqueous solution can probably be due to aggregation of Alg/ Fe 3 O 4 nanoparticles (as observed under TEM) and swelling of the alginate chains covering the nanoparticle surface. 48 50 Hence, our size was less than the previously reported. For TEM analysis, air-dried samples are used; hence actual dried size is obtained.…”

Preparation and Properties of Wet-Spun Microcomposite Filaments from Various CNFs and Alginate

“…The gelation of AL occurs due to the ionic cross-linkage of polyionic AL chains via Ca 2+ ions which can be conventionally described by the “egg-box” model [ 5 ]. At their G-segments, two alginate chains align antiparallel and the carboxyl groups of guluronic acid coordinately bind with Ca 2+ ions to form an egg-box-like structure, as shown in Figure 1 [ 6 ].…”

Alginate NiFe2O4 Nanoparticles Cryogel for Electrochemical Glucose Biosensor Development

“…However, the higher amount of the nanoparticles did not show a significant oxidation current change ( Figure 3 ). The nanoparticle composite in alginate polymers was generally prepared in the composition of 0–10% ( w / v ) such as in the alginate-magnetic nanoparticles [ 29 ], alginate silver nanoparticles [ 30 ], alginate-Fe 3 O 4 nanoparticles [ 31 ] and alginate multi-walled carbon nanotubes [ 32 ].…”