Zinc oxide/low-density polyethylene (LDPE) nanocomposites were prepared for intrauterine devices. The change of Zn 2+ release rates of nanocomposites (doped with various mass fractions of zinc oxide nanoparticles between 5wt% and 65 wt%) for 264 days in a simulated uterine solution were investigated. The results show that initial burst phases are followed by near zero-order release phases. SEM technique was employed to observe the surface morphology of the 45wt% ZnO/LDPE composite. Elements and phases on the surface of the nanocomposite after incubation were also analyzed by EDX and XRD respectively. The experimental results show that incrustation formation does not occur after incubation.
The analytical electron microscopy (AEM) was employed to observe the intratissuelar distribution of polysorbate 80 coated nanoparticles in brain with copper chlorophyll (CC), and a safe and cheap pigment was used as a marker. AEM analyses show that some nanoparticles are located at the wall of the microvasculum in brain, while others are distributed around the microvasculum in brain. These results may support that T-80 coated nanoparticles cross the BBB through mechanisms of endocytosis or transcytosis.
