Self-expanding sodium alginate sulfate drug-loaded microspheres for stabilized arterial embolization

Transarterial chemoembolisation (TACE) is an important treatment method for solid tumors, such as liver cancer. Its main advantages are precise treatment and reduced trauma. However, limitations including inadequate drug loading, burst release and ectopic embolization still exist in clinical practice. In this study, we developed sodium alginate sulfate microspheres (AM) with multiple types of drug-loading groups and self-expanding behavior, achieving superior drug loading capacity and embolization stability. The framework material sodium alginate sulfate (SAS) contains various drug-loading groups, resulting in fast drug loading (30 min, Doxorubicin hydrochloride), high loading capacity (68.0 mg/g, Irinotecan hydrochloride), sustained release (>30 days, Doxorubicin hydrochloride) and compatibility with multi-drug loading types (including gemcitabine hydrochloride and procaine hydrochloride). The fatty acid/sodium fatty acid buffer system formed at the aqueous-oil phase interface facilitated the formation of a gradient cross-linked structure, which conferred self-expansion behavior to the microspheres. In pig renal artery embolization (n = 9), the AM stabilizes the embolized artery, resulting in tissue necrosis without vascular recanalization or ectopic embolization (**p = 0.002 on 90 days). Therefore, AM with high drug-loading capacity and self-expansion has great potential to enhance the safety and efficacy of TACE treatment.