Lignin nanoparticles for photothermal-immunotherapy and preparation method thereof

The invention provides lignin nanoparticles for photothermal-immunotherapy and a preparation method thereof. The preparation method comprises the following steps of (1) uniformly dispersing lignosulfonate and indocyanine green in pure water to obtain a mixed solution; (2) under a normal-temperature stirring condition, dropwise adding an aluminum chloride solution into the mixed solution, and then carrying out a reaction in a dark place; and (3) after the reaction is finished, carrying out solid-liquid separation to obtain LS-Al-ICG nanoparticles. The LS-Al-ICG nanoparticles provided by the invention are uniform in particle size and relatively good in dispersity and stability; and a good photo-thermal conversion effect is achieved in vitro. An LS-Al-ICG nanoparticle solution with a proper concentration has good biological safety, 70% or above of tumor cells can be killed by combining with 808nm laser irradiation, and the LS-Al-ICG nanoparticles have an excellent anti-tumor effect in vitro and can stimulate imm