Transmission electron microscopy and electron diffraction study of BSA-loaded quaternized chitosan nanoparticles.

Chitosan nanoparticles, O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC) nanoparticles and bovine serum albumin (BSA) loaded chitosan and O-HTCC nanoparticles of a size (about 200-600 nm) were obtained through the process of ionic gelation between chitosan or O-HTCC and sodium tripolyphosphate (TPP). The physicochemical properties of nanoparticles made from chitosan, O-HTCC, BSA loaded chitosan, and BSA loaded O-HTCC were determined by transmission electron microscopy (TEM), polarized optical microscopy (POM), photon correlation spectroscopy (PCS), and X-ray diffraction (XRD) pattern. Zeta potential was also performed to understand the surface properties of nanoparticles and their ability to bind negatively charged BSA. TEM, POM, and XRD suggested that ionic-gelation process significantly influenced the crystallinity of BSA, and greater chain realignment in the BSA-loaded chitosan and O-HTCC nanoparticles. PCS revealed that BSA-loaded chitosan nanoparticles were bigger than chitosan nanoparticles in size and BSA-loaded O-HTCC nanoparticles were smaller than O-HTCC nanoparticles in size.