Chapter 7 - Development of lignin-based nanoparticles: fabrication methods and functionalization approaches

Abstract

Lignin is an aromatic polymer with great potential for the preparation of polymeric nanoparticles as this macromolecule is inexpensive, stable, relatively nontoxic, and highly biodegradable. Over the years, the development of lignin nanoparticles has been a subject of great interest to the scientific community as promising vehicles for important biomedical applications (e.g. drug and gene delivery, biomedical imaging), due to their ability to adsorb, encapsulate, or conjugate bioactive compounds within or onto their surface. Furthermore, lignin presents phenolic and aliphatic hydroxyl groups that can be chemically modify with targeting molecules, such as pH-sensitive polymers and targeting ligands, allowing a pH-responsive drug release and an increased cellular interaction with specific cells, respectively. In this chapter, the most important fabrication methods to obtain lignin nanoparticles such as, antisolvent precipitation, solvent exchange, sonication, and interfacial polymerization and cross-linking as well as the lignin nanoparticles functionalization approaches toward their use in biomedical applications, especially as drug and gene delivery vehicles will be discussed.