Synthesis of chitosan, pectin, and chitosan/pectin microspheres by two water-in-oil emulsion crosslinking methods

Structuration of biopolymers to provide a smart response in biological systems is of great interest considering potential applications in agriculture, pharmaceutics, and food industry. Namely, chitosan, pectin, and chitosan/pectin particles were obtained by one-step water-in-oil emulsion and water-in-oil emulsion-dehydration by crosslinking methodologies using glutaraldehyde and calcium chloride, correspondingly. Through our methodologies it was possible to obtain well-defined spherical particles with average sizes below two micrometers. In general, glutaraldehyde-crosslinked particles were larger than ionic crosslinked ones. The particle size and morphology of the materials were characterized by Dynamic Light Scattering and Scanning Electron Microscopy and the covalent and ionic interactions were determined by Infrared Spectroscopy. In most cases, we improved the size and/or morphology of the particles compared to base methodologies, as well contributed with its surface potential info and the chemical characterization of the systems. Overall, we obtained the structuring of spheres with potential for biological applications, according to its morphology, size, and superficial charge.