Legumain-triggered aggregable gold nanoparticles for enhanced intratumoral retention

Insufficient intratumoral retention of nanomedicines remains the major challenge for broad implementation in clinical sets. Herein, we proposed a legumain-triggered aggregable gold nanoparticle (GNP) delivery platform (GNPs-A&C). GNPs-A&C could form intratumoral or intracellular aggregates in response to the overexpressed legumain. The aggregates with size increase not only could reduce back-flow from interstitial space to peripheral bloodstream but also could restrict the cellular exocytosis, leading to enhanced intratumoral retention. In vitro studies demonstrated that GNPs-A&C possessed an excellent legumain responsiveness and the increased size was closely relevant with legumain expression. In vivo studies demonstrated GNPs-A&C possessed slower clearance rate and much higher intratumoral retention within legumain-overexpressed tumor compared to non-aggregable NPs, regardless of intravenous or intratumoral injection. More importantly, this delivery platform significantly improved the chemotherapeutic effect of doxorubicin (DOX) towards subcutaneous xenograft C6 tumor. The effectiveness of this stimulus-responsive aggregable delivery system provides a thinking for designing more intelligent size-tunable nanomedicine that can substantially improve intratumoral retention.