A pH-responsive controlled release model for bortezomib (BTZ) based on catechol borate ester bond has been constructed successfully by poly(ethylene glycol) (PEG)

dodecylamine (DDA) and dopamine (DPA)-modified poly itaconic acid (PIA) (PIA-PEG-DDA-DPA-BTZ).Its structure was characterized by nuclear magnetic resonance (NMR).The result showed that the targeted products were prepared successfully.The PIA-PEG-DDA-DPA-BTZ was then made into micelles.The sizes of the micelles formed by the polymer were tested by dynamic light scattering (DLS)

and observed under atomic force microscope (AFM).According to the test

the micelles showed a spherical and monodispersed construct with very small diameter of about 35 nm.The critical micelle concentration (CMC) value was 2.5410-3 mg/mL via pyrene fluorescence method.The standard curve of BTZ was portrayed based on the characteristic absorption peak of BTZ at 300 nm in UV-Vis absorption.The cumulative release rates of BTZ conjugates were then studied at pH 5.0 and pH 7.4

and the release behavior at pH 5.0 fits the first order kinetics model

Q=61.65866-62.13481e-0.32544t

the coefficient of determination was 0.99798.The cell viability studies showed that the micelles had a quite significant inhibitory effect on cancer cells which is close to that of the pure bortezomib.The pH-responsive controlled release model has the potential of becoming a promising diagnostic tool in clinical application for cancer treatment.