Development of artificially engineered nanoparticles by surface modification and their biomedical applications

Abstract

The effectiveness of cobalt-substituted magnesium ferrite Mg1-xCoxFe2O4 (MCFO) (0 x 1 with x = 0.1) and polymer nanohybrids for biomedical applications, particularly as the contrast agent for magnetic resonance imaging/angiography and thermotherapeutic applications for malignant lesion, was investigated by synthesizing these nanoparticles using the chemical co-precipitation method. Nanomaterials employed as effective media for successful applications in the disciplines mentioned above are determined by the engineering parameter, which works as the figure-of merit: the relaxivities (r1 and r2) for MRI and specific loss power (SLP). Particle size, shape, distribution, and coating agent affect magnetization and anisotropy, which impacts the parameters of relaxivities and specific loss power. It is intriguing to note that the anisotropy and particle volume substantially control the relaxivities and specific loss powers, which Néel and Brownian relaxation govern. Relaxivities and specific loss of power can be either beneficial or detrimental by hysteresis loss. When the ratio of the MRI negative relaxivity values (r2) to the positive reference value (r1) is high, the contrast agent has a negative effect, and vice versa when the ratio is low. The values of r1 and r2 are highly sensitive to the nanoparticle's magnetic and structural characteristics. Again, SLP is highly dependent on magnetic anisotropy, and limited anisotropy will always increase the value of SLP, leading to better hyperthermia performance. Spin flip at radio rf magnetic fields and Neel relaxation are impeded under higher anisotropy conditions. Again, Brownian relaxation is frustrated by the large particle size. Anisotropy and structural characteristics were investigated in Co-substituted Magnesium ferrite with an atom fraction increase of x = 0.1. MRI/MRA contrast agents were studied using particles VIII of all compositions in their as-prepared state. Particle size dependence SLP and temperature rise for hyperthermia and/or laser ablation were studied by varying the size of the particles through controlled annealing at 200°C, 400°C, 600°C, and 800°C, and then encapsulating the particles in chitosan. This study aims to learn the structure-property relationship and their effect on magnetic nanoparticle-mediated MRI and thermotherapy using MCFO and chitosan/dextran/polyethylene glycol (PEG) nanohybrid.