Lignin-based fluorescence hollow nanoparticles: Their preparation, characterization, and encapsulation properties for doxorubicin

Lignin shows strong adsorption, biodegradability and non-toxicity, and has opened a research hotspot in the design and manufacture of controllable nanomaterials for drug delivery. However, lignin-based materials, with both diagnostic and therapeutic functions, have yet to be developed. In this work, enzymatically hydrolysable lignin (EHL) was used to prepare blue fluorescent lignin copolymer by grafting 1-Pyrenebutyric acid onto lignin via amidation reaction and then formed self-assembled nanoparticles. The results show that such lignin-based hollow nanoparticles exhibit characteristics of fluorescent functions, size controlled and stable structure within 15 days. For anticancer drug Doxorubicin, the encapsulation efficiency and drug loading reached, respectively, 50% and 10%. This encapsulation had no cytotoxicity, and sustained-release effect on the drug. The aim of this study was to develop the multifunctional bio-nanomaterials for medical applications, through simple, environmentally friendly, low-cost methods.