Functionalized nanoparticles based on β-chitosan and styrene copolymer derivative for donepezil delivery

Developing a drug delivery strategy that can cross the blood-brain barrier is crucial to effective neurological treatment. In this work, a new strategy was introduced for efficient drug delivery of Donepezil based on the preparation of polyelectrolyte complexes (PEC) nanogel from β-chitosan (CS) and the prepared sulfonated styrene-maleic anhydride (S-SMA). First, low-molecular-weight SMA was prepared. Then, sulphonation of SMA was carried out. Three PEC nanoparticles were prepared by mixing three different ratios of S-SMA with β-chitosan. The structure and characteristics of the nanoparticles were thoroughly investigated. Varying S-SMA content (donated CS-S1, CS-S2, and CS-S3) for fixed a β-CS content, the surface charge and average size of the nanoparticles were tunable. Donepezil hydrochloride (DH) was encapsulated successfully in the nanoparticles CS-S3 and donated as CS-S3-DH. Additionally, the transmission electron microscopy (TEM) images revealed that almost 50% of the nanoparticles particles had diameters of 27 ± 0.1 and 111 ± 0.4 nm for CS-S3 and CS-S3-DH, respectively. The in vitro drug release study indicates a sustained release of DH for 72 h. In addition, the in vitro acetylcholinesterase (AChE) inhibitory was investigated. The result showed that AChE inhibitory percentages were 16.5 and 63.9% for CS-S3 and CS-S3-DH, respectively.