A novel chitosan-citric acid crosslinked beta-cyclodextrin nanocarriers for insoluble drug delivery.

In this work a new system nanocarrier consisting of chitosan (CS) and beta-cyclodextrin crosslinked citric acid (pbCD) was prepared. Curcumin (cur), which is well-known for having a wide range of biological properties suitable for the treatment of several diseases, was selected as a model for forming the inclusion complex in pbCD and then encapsulated into CS nanoparticles (CSpbCD-cur). The effects of both the concentration of pbCD-cur and the pH were investigated. The CSpbCD-cur nanoparticles were characterised by SEM, FT-IR, DLS, drug loading and in vitro release. The results showed that the size of CSpbCD nanoparticles were unstable at higher pH values (pH ≥ 6) and pbCD concentrations. Moreover, the loading efficiency of the inclusion complex of curcumin with pbCD (pbCD-cur) entrapped into the CS nanoparticles (CSpbCD-cur), increased when the pbCD-cur concentration was increased. The size and size distritution (PDI) of nanoparticles showed the best at the concentration of pbCD-cur 20 mL/mg (with 1.5 mg/mL of CS) at pH 4. The release profile showed that CSpbCD-cur had a slower release than free curcumin resulting in that the cytotoxicity of CSpbCD-cur was less than that of pbCD-cur, and free curcumin, respectively.