Role of lignin-based nanoparticles in anticancer drug delivery and bioimaging: An up-to-date review

Lignin, an aromatic biopolymer, is the second most abundant naturally occurring one after cellulose that has drawn a great deal of interest over the years for its potential uses owing to the presence of high content of phenolic compounds, ecofriendly feature and cost-efficiency in comparison to the synthetic polymers. Never-theless, with the intention of advancing its development, several efforts have been performed in the direction of utilizing lignin on the nanoscale due to its inimitable properties. The notable absorption capacity, fluorescence emission, biodegradability and non-toxicity of lignin nanoparticles permit its appropriateness as a vehicle for drugs and as a bioimaging material. Moreover, lignin nanoparticles have shown plausible therapeutic effects, such as anticancer, antimicrobial, and antioxidant. The current review sheds light on the recent development in the formulation and anticancer applications of lignin nanoparticles as a drug carrier and as a diagnostic tool. The surface properties of the nanomaterial affect the end product characteristics, hence, factors namely; lignin source, isolation technique, purification and quantitation methods, are discussed in this review.This study represents original work that has not been published elsewhere and that has not been submitted simultaneously for publication elsewhere. The manuscript has been read, revised, and approved by the authors.