Chapter 29 - Treatment of heavy metal induced neurotoxicity via advanced drug delivery systems

Abstract

Heavy metals are a group of elements that have high atomic weight, chemical reactivity, density, or specific gravity compared to water. Some of the most toxic heavy metals are lead, arsenic, cadmium, and mercury, which can enter the body through breathing, eating, or skin contact. These metals can persist in the body for a long time and cause irreversible effects. They can cause neurotoxicity, which is the damage of the brain and nervous system by interfering with their normal functions. Neurotoxicity can be acute or chronic, depending on the duration and the amount of exposure. Children are especially vulnerable to heavy metal exposure, as it can impair their cognitive and behavioral development. Heavy metals can induce neurotoxicity by various mechanisms, such as generating oxidative stress and free radicals, disrupting the balance of antioxidants and micronutrients, and binding to macromolecules. Heavy metals are widely present in the environment and can accumulate in the body without being noticed until they cause chronic health problems. Heavy metal toxicity can affect anyone regardless of age, gender, race, or location, but the central nervous system is the most sensitive and affected organ. One of the challenges in treating neurotoxicity caused by heavy metals is to deliver medicines across the blood-brain barrier to the targeted brain regions. One way to overcome the challenge of delivering drugs across the blood-brain barrier (BBB) is to use nano formulations, such as solid lipid nanoparticles (SLNs). SLNs can encapsulate drugs (drug-loaded SLNs) and transport them to the brain, where they can release them at the desired site. SLNs have many benefits over traditional drug delivery systems, such as targeted specificity, higher efficacy, controlled drug release, longer circulation time and less to minimum toxicity, mimicking the natural biological processes.