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.