Synthesis of β-cyclodextrin modified chitosan-poly(acrylic acid) nanoparticles and use as drug carriers

β-Cyclodextrin modified chitosan-poly(acrylic acid) nanoparticles (CS-PAACD NPs) were obtained by polymerizing acrylic acid (AA) and β-cyclodextrin (β-CD) substituted acrylic acid (AACD) in chitosan (CS) solution. These CS-PAACD NPs, characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) as well as atomic force microscopy (AFM), were quite small in size about 40-50 nm. The size and the microstructure of these CS-PAACD NPs could be accurately controlled by changing the ration of AACD to AA. As the ratio of AACD to AA increased, the size of these NPs decreased. These as-prepared CS-PAACD NPs showed enhanced solubility for paclitaxel (PTX) in aqueous solution and exhibited a typical pH-sensitive release property for the encapsulated drug in vitro. The presence of the β-cyclodextrin inside the CS-PACD NPs greatly enhanced the ability to load hydrophobic drugs, which significantly broadened the application of CS-PAACD NPs in biomedical fields.