Current overview of inorganic nanoparticles for the treatment of central nervous system (CNS) diseases

Although the integrity of the Blood-brain Barrier (BBB) is often compromised in several Central nervous system (CNS) disorders, the release of therapeutic or diagnostic agents in the brain remains challenging. Indeed, most of the currently established diagnostic and therapeutic protocols result ineffective in treating and detecting CNS diseases. In this context, it is essential to develop novel strategies that allow a targeted release of the therapeutic agents to the brain, overcoming the BBB. The technological advances of the last decade have led to the development of new techniques for nanoscale treatment and diagnosis of brain diseases. Several nano-formulations have been recently proposed and successfully tested in preclinical models for their capacity to cross the BBB, in particular when chemically modified with the intent to exploit specific transport processes that normally occur at the interface between blood and endothelium of the cerebral vasculature. In this review, the tunable physico-chemical characteristics of inorganic nanoparticles will be reviewed, and how this aspect can offer the possibility to improve current therapeutic strategies. The local and systemic toxicity of these nanomaterials will be also analyzed. Furthermore, we will provide an update on recent key advancements in the design and synthesis of novel inorganic core-lipid shell nanoparticles for the treatment of CNS disorders, and how these vectors may overcome challenges faced by current inorganic nanomaterials.