Synthesis and characterization of CoxFe1-xFe2O4 nanoparticles by anionic, cationic, and non-ionic surfactant templates via co-precipitation.

The cobalt ferrite nanoparticles (CoxFe1-xFe2O4) were synthesized by the surfactant templated co-precipitation method using various surfactants namely sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), and Tween20. Under the substitution, the CoxFe1-xFe2O4 particles were synthesized at various Co2+ and Fe2+ mole ratios (x = 1, 0.6, 0.2, and 0) with the SDS. The cobalt ferrite nanoparticles were characterized for their morphology, structure, magnetic, and electrical properties. All CoxFe1-xFe2O4 nanoparticles showed the nanoparticle sizes varying from 16 to 43 nm. In the synthesis of CoFe2O4, the SDS template provided the smallest particle size, whereas the saturated magnetization (Ms) of CoFe2O4 was reduced by using CTAB, SDS, and Tween20. For the CoxFe1-xFe2O4 as synthesized by the SDS template at 1.2 CMC, the Ms increased with increasing Fe2+ mole ratio. The highest Ms of 100.4 emu/g was obtained from the Fe3O4 using the SDS template. The Fe3O4 nanoparticle is potential to be used in various actuator and biomedical devices.

Electrically controlled release of anticancer drug 5-fluorouracil from carboxymethyl cellulose hydrogels.

Transdermal drug delivery is a technique used to introduce a drug through the skin and into the blood system. The drug-matrix hydrogels based on carboxymethyl cellulose (CMC) were prepared by solution casting method using citric acid as the crosslinking agent at various amounts. The 5-fluorouracil, an anticancer non-ionic drug, was released from the CMC hydrogels under applied electrical field. The diffusion coefficient and the release mechanism of the drug of the CMC hydrogels were investigated by the modified Franz-diffusion cell with the PBS buffer solution at the pH value of 7.4 and at 37 °C for the duration of 24 h. The effects of mesh size, electric potential, and electrode polarity were systematically investigated. The swelling test illustrated an increase in the mesh size with decreasing crosslinking agent. In addition, the drug diffusion coefficient increased with decreasing crosslinker: repeated group mole ratio. The diffusion coefficient depended critically on the applied electric potential and the electrode polarity. The non-ionic drug release mechanisms were identified as the matrix deswelling and electroosmosis, in addition to the pure diffusion without electric field. Thus, CMC has been shown a potential bio-based matrix for electrically controlled non-ionic drug delivery.