This volume deals with chemical modification, structure-property relationship, biological interaction and biomedical applications of chitosan and its chemically modified derivatives. The chapters of this volume provide an overview of the structural comparison of chitosan with other sugar-based biopolymers, a different type of strategy used in chemical modification of chitosan to interact with metal ions and to enhance antimicrobial activity. The chapters further discuss the development of functionalized chitosan hydrogels, films, scaffolds and composites that have the potential to be used in food packaging, enhancing saltiness, biosensors and wound dressing. In addition the fabrication and biological properties of chitosan and its derivatives-based nanofibers are presented. Another important aspect covered in this volume is that of the interaction of chitosan with blood, platelet-rich plasma and stem cells. Finally, this volume presents the current challenges in the development of biomedical products based on chitosan and its derivatives. The volume will be of interest to chemists, material science, biological science and biomaterial scientists can able to understand structure-property relationship, biological interaction and biomedical applications of chitosan and its derivatives.