RESUMO
A magnetic nanocomposite, consisting of Fe3O4 nanoparticles embedded into a Mg/Al layered double hydroxide (LDH) matrix, was developed for cancer multimodal therapy, based on the combination of local magnetic hyperthermia and thermally induced drug delivery. The synthesis procedure involves the sequential hydrolysis of iron salts (Fe2+, Fe3+) and Mg2+/Al3+ nitrates in a carbonate-rich mild alkaline environment followed by the loading of 5-fluorouracil, an anionic anticancer drug, in the interlayer LDH space. Magnetite nanoparticles with a diameter around 30 nm, dispersed in water, constitute the hyperthermia-active phase able to generate a specific loss of power of around 500 W/g-Fe in an alternating current (AC) magnetic field of 24 kA/m and 300 kHz as determined by AC magnetometry and calorimetric measurements. Heat transfer was found to trigger a very rapid release of drug which reached 80% of the loaded mass within 10 min exposure to the applied field. The potential of the Fe3O4/LDH nanocomposites as cancer treatment agents with minimum side-effects, owing to the exclusive presence of inorganic phases, was validated by cell internalization and toxicity assays.
RESUMO
Ventriculoperitoneal shunt (VPS) placement is one of the commoner neurosurgical procedures worldwide. The purpose of this article is to report a case of delayed intraventricular hemorrhage (IVH) following a VPS and to review the literature regarding anatomic factors that could potentially explain this rare complication. A 78-year-old man with normal pressure hydrocephalus, who underwent an uneventful right VPS placement, suffered from a catastrophic isolated IVH five days later. The reported cases of delayed intracerebral hemorrhage (ICH) following VPS are rare and those with IVH are even rarer. Potential factors of surgical anatomy that could cause delayed ICH/IVH following a VPS procedure include erosion of vasculature by catheter cannulation, multiple attempts at perforation, puncture of the choroid plexus, improper placement of the tubing within the brain parenchyma, VPS system revision, venous infarction, vascular malformations, head trauma, and brain tumors. Other causes include generalized convulsion, VPS system malfunction, increased intracranial or blood pressure, sudden intracranial hypotension, and bleeding disorders. According to the current literature, our case is the first reported delayed isolated IVH after a VPS placement so far. Neurosurgeons should be aware of the delayed ICH/IVH as a rare, potentially fatal complication of VPS, as well as of its risk factors.
