Biomagnetic of Apatite-Coated Cobalt Ferrite: A Core–Shell Particle for Protein Adsorption and pH-Controlled Release

Magnetic nanoparticle composite with a cobalt ferrite (CoFe2O4, (CF)) core and an apatite (Ap) coating was synthesized using a biomineralization process in which a modified simulated body fluid (1.5SBF) solution is the source of the calcium phosphate for the apatite formation. The core–shell structure formed after the citric acid–stabilized cobalt ferrite (CFCA) particles were incubated in the 1.5 SBF solution for 1 week. The mean particle size of CFCA-Ap is about 750 nm. A saturation magnetization of 15.56 emug-1 and a coercivity of 1808.5 Oe were observed for the CFCA-Ap obtained. Bovine serum albumin (BSA) was used as the model protein to study the adsorption and release of the proteins by the CFCA-Ap particles. The protein adsorption by the CFCA-Ap particles followed a more typical Freundlich than Langmuir adsorption isotherm. The BSA release as a function of time became less rapid as the CFCA-Ap particles were immersed in higher pH solution, thus indicating that the BSA release is dependent on the local pH

New approaches to the study of spinel ferrite nanoparticles for biomedical applications

This chapter is prepared into six different sections. The first part will provide a brief introduction of spinel ferrite nanoparticles synthesis, the use of chelating agents in the sol-gel method, and applications of spinel ferrite nanoparticles in biomedical fields. The second part will cover an overview of the structure and magnetism of spinel ferrites. The third part will present a summary of different types of chelating agents. The fourth part will provide information of the sol-gel synthesis for ceramic nanoparticles. The fifth part will focus on the preparation of cobalt ferrite nanoparticles by sol-gel methods using polyvinyl alcohol (PVA) and citric acid (CA) as chelating agents. The influence of chelating agents on the physical properties and antibacterial property of cobalt ferrite nanoparticles will be highlighted in the last part. A discussion on chelating agent-metal ion formation and the antibacterial mechanisms of spinel ferrite nanoparticles will be presented