Synthesis, characterization of biomimetic phosphorylcholine‐bound chitosan derivative and in vitro drug release of their nanoparticles

Novel water‐soluble biomimetic phosphorylcholine (PC)—bound chitosan derivatives ( N ‐PCCs) with different degree of substitution (DS) via a phosphoramide linkage between glucosamine and PC were synthesized through Atherton‐Todd reaction under the mild conditions, and structurally characterized by 1 H‐NMR, Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), X‐ray diffraction (XRD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Their DS ranged from ∼ 16 to ∼ 42 mol % based on the 1 H‐NMR spectra. All these N ‐PCCs with decreased crystallization showed excellent solubility in the aqueous solutions within a wide pH range (1–12). DSC and TGA results revealed that the thermal stability of N ‐PCCs decreased with the increase of DS value. Further, N ‐PCCs nanoparticles could be still formed in a spherical shape similar to chitosan nanoparticles by ionic gelation technique, observed by atomic force microscopy (AFM). Dynamic light scattering (DLS) results suggested that the zeta potential value of N ‐PCCs nanoparticles decreased with the DS value increasing. Using 5‐fluorouracil (5‐Fu) as a model drug, in vitro drug release studies indicated that N ‐PCCs nanoparticles exhibited a similar prolonged release profile as chitosan nanoparticles. The results suggested that N ‐PCCs nanoparticles could be used as promising nanocarriers for drug delivery applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013