Lignins and their potential for use as biopolymers in pharmaceutical engineering - a review

Nature offers a diverse set of renewable biopolymers, among them the variety of natural polyphenols, whose structural diversity provides opportunities for further manipulation like the generation of chemicals and novel functional materials. These land‑based renewable biomaterials exhibit also a wide range of heterogeneous intrinsic reactivities and activities that render them ideal starting oligomeric and polymeric materials for the generation of multifunctional supramolecular structures as well as the development of high value-added materials. Lignins in particular display a variety of common physico‑chemical features that can be of enormous interest with respect to their eventual use in the pharmaceutical area. These natural polyphenols possess some interesting pharmaceutical properties such as antioxidant, anti‑inflammatory, antibacterial and eventually antiviral activities. In addition, based on their chemical features, i.e., oligomers and/or polymers of monolignol C9-building blocks. lignins can be exploited in the pharmaceutical sector mainly as material for generation of matrices and carriers for drug delivery. The present work attempts a review of the state of the art in lignin use in pharmaceutical applications. Keywords biopolymers, lignins, microcapsules, nanoparticles, renewable resource