Polymeric or enzymatic degradation thus increasing the chances

 Polymeric nanoparticles(NPs) are colloidal carriers into which drugs are loaded in either solid stateor solution, adsorbed non-covalently or chemically linked to the surface Polymericnanoparticles (NPs) are colloidal carriers into which drugs are loaded ineither solid state or solution, adsorbed non-covalently or chemically linked tothe surface.1  In recent times,PNPs are extensively employed as biomaterials because of their favourablecharacteristics in terms of simple elaboration and design, goodbiocompatibility, a broad structures variety and noticeable bio-imitativecharacteristics.

Expressly in smart drug delivery discipline, PNPs had a markedrole as they are able to bring therapeutics right into the purposed position inhuman body, with excellent efficiency2. Polymeric NPs have been usedas a preferred nanoscale drug delivery vehicle especially for their highencapsulation efficiency, excellent endocytosis efficiency, passivetumor-targeting,  and delivery of a widerange of therapeutic agents3.   These Np possess some advantages with respectto single molecules of drugs or prodrugs, such as their high drug-loadingcapacity. It is, therefore, possible to deliver a great number of drugmolecules into cells for each Np.

In addition, Np provide protection to theembedded drugs against chemical or enzymatic degradation thus increasing thechances of the active molecule reaching the target site. Furthermore, it ispossible to modify the Np surface properties in order to facilitate drugdelivery, for example, escape from the RES system4.  Several polymers have been used toproduce NPs for CNS delivery using different preparation techniques dependingon polymer and drug features. Interestingly, aiming to increase theircirculation lifetime and improve drug delivery across BBB, NPs surfaceproperties can be modified by either adsorption or chemical grafting ofpolyethylene glycol (PEG), poloxamers or other molecules, that increase their circulationlifetime and improve drug delivery across the BBB.5 Asa result of the diversity of polymers, polymeric nanoparticles can be designedto achieve desired properties such as controlled and/or sustained drug releaseprofile, as well as allowing drug release at the targeted site over a period oftime6For this reason, avariety of polymers have been investigated to form nanoparticles for brain drugdelivery.