Due to their exceptional absorption capacity, biodegradability, and non-toxicity, nanoparticles (NPs) from lignin have emerged as vehicles for inorganic particles and drug molecules. However, the method for preparing targeted lignin particles is still complex and lacks sufficient research. Herein, a succinct strategy was proposed for the preparation of targeted lignin-based drug delivery NPs to load Doxorubicin Hydrochloride (DOX). The lignin hollow NPs (LHNPs) were used as a platform for the preparation of targeted delivery material by incorporating magnetic NPs and folic acid (FA) via layer-by-layer self-assembling. The results showed that the surface of LHNPs was covered uniformly by Fe₃O₄ NPs and grafted with folic acid. The folic-magnetic-functionalized lignin hollow NPs (FA-MLHNPs) could respond to magnetic field and folic acid receptors. In addition, the targeting performance of the FA-MLHNPs increased the cellular uptake of NPs in the case of HeLa cells. This research not only supported the modified NPs platform as a highly efficient nano-delivery method but also provided a facile approach to utilize renewable lignin biomaterials.

Because of their exceptional absorption capacity, biodegradability, and nontoxicity, nanomaterials fabricated from renewable natural resources have recently become an increasingly important research area. However, the mechanism of drug encapsulation by lignin nanoparticles and the role of nanoparticle structure on the stability and loading performance still remain unknown. Herein, lignin hollow nanoparticles (LHNPs) were prepared and applied as promising vehicles for the antineoplastic antibiotic drug doxorubicin hydrochloride (DOX). The hydrogen bonding and π−π interactions contributed to the encapsulation of hydrophilic DOX by LHNPs with hydrophobic cavities. The encapsulation of DOX was enhanced by the pore volume and surface area. In addition, the nanoparticles contributed to the cellular uptake and the accumulation of the drug within HeLa cells. This work provides a scientific basis for future studies on the selective entrapment properties of hollow polymer nanoparticles derived from biomass material as vehicles for overcoming pharmacokinetic limitations.

Due to its abundance, degradability, and low toxicity, lignin is a promising raw material for the preparation of nanomaterials. However, efficient encapsulation using lignin-nanomaterial for sustained-release medications remains a challenge. This study involves grafting β-cyclodextrin (β-CD), with a hollow toroidal structure, onto the enzymatic-hydrolysis lignin (EHL) to form CD-EHL. The modified lignin was next used to prepare hollow nanoparticles (LHNPs) via self-assembly to encapsulate the antitumor drug hydroxycamptothecin (HCPT). The results indicated that β-CD improved the network structure of modified lignin molecules. Moreover, LHNPs that self-assembled using CD-EHL had an increased specific surface area and greater porosity, and exhibited a spherical hollow structure and stability in phosphate-buffered saline. The drug loading and encapsulation efficiency of HCPT were 70.6 ± 9% and 22.02 ± 2%, respectively. An in vitro study showed that lignin-based nanoparticles have low toxicity, and the modified LHNPs demonstrated a good sustained-release capability. This study broadened the potential application of lignin as a renewable biomass material.