Injectable gel self-assembled by paclitaxel itself for in situ inhibition of tumor growth

Injectable gels as a new avenue have demonstrated profound promise for the treatment of cancers. However, the long-lasting but far-reaching challenge of in situ treatment of cancers is how to construct an injectable gel only with original chemotherapeutic agents. In this work, we reported injectable gels with a high and quantitative drug loading based on the self-assembly of paclitaxel (PTX) itself. Non-covalent forces, hydrogen bond interactions and π-π stacking, play a crucial role in the formation of PTX gels. In vivo gel retention experiment illustrates that PTX gel remains in situ post injection for more than 40 days. Compared with saline and PTX (intravenous and in situ administration), subcutaneous injection of PTX gel not only reduces the toxicity of the drug in normal organs, resulting in the increase of mouse body, but also maintains sustained release of PTX in the tumor vicinity and thereby displays excellent antitumor activity. The results of histopathological analysis indicate that PTX gel shows less side effects or systemic toxicity to the normal organs, and more importantly, effectively inhibits tumor metastasis. This novel injectable PTX gel has great potential as an effective self-assembly system in situ treatment of cancers.