Chemical Modifications of Lignin for Biomedical Applications

Abstract

Lignin is a natural aromatic renewable biopolymer which can be chemically changed to make it acceptable for varied uses. This is possible due to its numerous active groups, such as hydroxyl groups (phenolic and alcoholic), as well as its carbon–carbon double bonds. Unfortunately, the heterogeneity of lignin makes it difficult to produce lignin derivatives with biomedical applications. Extraction and chemical modification techniques need to be improved to obtain homogeneous lignin macromolecules. On the other hand, lignin presents high levels of antioxidant and antimicrobial activity and low cytotoxicity, which strongly recommends it as a candidate for medical applications. This chapter provides a brief overview of the chemical modifications of lignin for biomedical applications, especially as antimicrobial agents, as delivery systems, and in tissue engineering, along with innovative concepts for the use of lignin in life sciences.