ABSTRACT
Lipid nanostructures are nanosized systems ranging in size from 1 to 500 nm and are classifi ed into two main groups: Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC); moreover, they have a great potential to carry lipophilic or hydrophilic drugs, and diagnostics (Kaur et al. 2008). Size, surface charge, morphology and matrix composition play a fundamental role for their in vivo fate and all these features can be modulated accordingly to obtain suitable modifi ed release profi le,
biological activity and compatibility. Lipid nanoparticles are administrable for all routes even for intravenous route being smaller than the size of the smallest vessels. Their use as TDDS is associated with many advantages that include biocompatibility/biodegradability, an excellent storage stability, a relatively easy production without the use of any organic solvent, the possibility of steam sterilization and lyophilization, and large scale production. The surface modifi cation with hydrophilic polymers improves their pharmacokinetic behaviour with an increase of the mean residence time in bloodstream (Beduneau et al. 2007). In order to optimize their biodistribution, these vectors can be surface decorated by site-specifi c biomolecules recognizing target tissue. These latter biomolecules focus on nanocarriers able to deliver specifi cally drugs to cerebral tissues by active transport mechanisms (Koziara et al. 2004).
