RESUMO
AIMS: Cancer-related thrombosis (CAT) is a common complication in cancer patients, significantly impacting their quality of life and survival prospects. Nattokinase (NK) has potent thrombolytic properties, however, its efficacy is limited by low oral bioavailability and the risk of severe allergic reactions with intravenous use. Heparin (HP) is a widely used anticoagulant in clinical settings. This study aimed to overcome the intravenous toxicity of NK and explore its effect on CAT in advanced tumors. MAIN METHODS: In this study, NK-HP electrostatic complexes were constructed, and their safety and thrombolytic efficacy were verified through guinea pig allergy tests, mouse tail vein tests, and both in vivo and in vitro thrombolysis experiments. Additionally, an S180 advanced tumor model was developed and combined with sialic acid-modified doxorubicin liposomes (DOX-SAL) to investigate the impact of NK-HP on CAT and its antitumor effects in advanced tumors. KEY FINDINGS: We observed that NK-HP can eliminate the intravenous injection toxicity of NK, has strong thrombolytic performance, and can prevent thrombosis formation. Intravenous injection of NK-HP can enhance the antitumor effect of DOX-SAL by reducing the fibrin content in advanced tumors and increasing the levels of the cross-linked protein degradation product D-dimer. SIGNIFICANCE: This study developed a method to eliminate the intravenous injection toxicity of NK, proposing a promising therapeutic strategy for CAT treatment, particularly for CAT in advanced tumors, and improving the efficacy of nano-formulations in anti-tumor therapy.