Magnetic/pH-sensitiveκ-carrageenan/sodium alginate hydrogel nanocomposite beads: preparation, swelling behavior, and drug delivery

Abstract

This work describes the preparation of magnetic and pH-sensitive beads based on κ-carrageenan and sodium alginate for use as drug-targeting carriers. Physical cross-linking using K(+)/Ca(2+) ions was applied to obtain ionic cross-linked magnetic hydrogel beads. The produced magnetite beads were thoroughly characterized by TEM, SEM/EDS, XRD, FTIR, and VSM techniques. While the water absorbency (WA) of magnetic beads was enhanced by increasing the weight ratio of κ-carrageenan, introducing magnetic nanoparticles caused a decrease in WA capacity from 15.4 to 6.3 g/g. Investigation on the swelling of the hydrogel beads in NaCl, KCl, and CaCl2 solutions revealed the disintegration of beads depending on the composition of hydrogel beads and the type of metal cations in swelling media. The swelling ratio of beads indicated pH-dependent properties with maximum water absorbing at pH 7.4. Also, it was found that the strength of pH-sensitivity of magnetic beads was low for beads with the high content of carrageenan component. The in vitro drug release studies from hydrogels exhibited significant behaviors on the subject of physiological-simulated pH values and external magnetic fields. The maximum cumulative releases obtained were 98 and 43% at pH values 7.4 and 1.2, respectively. The Introducing magnetite nanoparticles influenced the cumulative release of drug.

Magnetic field responsive methylcellulose-polycaprolactone nanocomposite gels for targeted and controlled release of 5-fluorouracil

“…This restriction causes to retard the drug release under magnetic field [71,72]. This behavior is very similar to those reported in the literature [46,[73][74][75]. However, there are different results for some temperature sensitive polymers and increasing in drug release has been reported for these kinds of magnetic sensitive systems.…”

“…The characteristic peaks for MC-PCL-M 1 films at 2h ¼ 30.2°, 35.5°, and 43.1°can be attributed to the indices (2 2 0), (3 1 1), and (4 0 0) of the Fe 3 O 4 nanoparticles, respectively [46]. The data obtained confirmed the existence of Fe 3 O 4 nanoparticles in the structure of magnetic films and showed that the crystallinity of gels increased when Fe 3 O 4 nanoparticles were added.…”

“…The dry gels were coated with gold layer using sputter-coating, and their SEM and SEM-EDS pictures were taken. Element compositions (C, O, and Fe) of the samples were investigated by the energy-dispersive X-ray spectroscopy (EDS) studies [46,47]. In the EDS spectrum, each element shows characteristic X-rays that are exhibited as peaks at specific energy levels.…”

Amphoteric gellan gum-based terpolymer–montmorillonite composite: synthesis, swelling, and dye adsorption studies

“…The swelling of the gel is due to osmotic pressure difference developed between the gel and the external salt solution due to the charge screening effect of the salt solution. The composite hydrogels exhibited salt sensitivity as reported in the literature [38,39].…”

In vitro evaluation of anti-calcification and anti-coagulation on sulfonated chitosan and carrageenan surfaces

“…Carrageenan can be utilized in various forms as beads [9,10], films [11,12], and polyelectrolyte complexes (PEC) [12,13]. Figure 1C shows the κ-carrageenan structure.…”