Research Progress on Lignin-Based Microcapsules for Drug Protection and Release

Abstract

In recent years, spherical particles derived from natural bio-based feedstocks have garnered growing interest owing to their distinctive morphologies, structural versatility, and capacity for facile surface functionalisation. Lignin, the most abundant aromatic biopolymer in nature, possesses inherent antibacterial and antiviral activity together with excellent biocompatibility, underscoring its considerable promise for pharmaceutical, cosmetic, and food-sector applications. Preliminary studies have already demonstrated the successful deployment of spherical lignin particles as drug-delivery vehicles—for instance, in the encapsulation of therapeutics for oncological treatment, as well as in the controlled release of insecticides and antimicrobial agents for agrochemical applications. This contribution begins by outlining the fundamental physicochemical attributes of lignin-based drug-loaded microcapsules and the factors governing active-agent release. Detailed discussions of fabrication methodologies, attendant characteristics, and comparative advantages are then presented. Subsequently, recent advances in the utilisation of lignin-based microcapsules within biopharmaceutical and chemical-pesticide contexts are reviewed, together with the critical challenges that remain to be resolved. Finally, prospective directions for the future evolution of lignin-based drug-loaded microcapsules are highlighted.