Following
surgical resection for primary treatment of solid tumors,
systemic chemotherapy is commonly used to eliminate residual cancer
cells to prevent tumor recurrence. However, its clinical outcome is
often limited due to insufficient local accumulation and the systemic
toxicity of anticancer drugs. Here, we propose a sprayable adhesive
nanoparticle (NP)-based drug delivery system using a bioengineered
mussel adhesive protein (MAP) for effective locoregional cancer therapy.
The MAP NPs could be administered to target surfaces in a surface-independent
manner through a simple and easy spray process by virtue of their
unique adhesion ability and sufficient dispersion property. Doxorubicin
(DOX)-loaded MAP NPs (MAP@DOX NPs) exhibited efficient cellular uptake,
endolysosomal trafficking, and subsequent low pH microenvironment-induced
DOX release in cancer cells. The locally sprayed MAP@DOX NPs showed
a significant inhibition of tumor growth <i>in vivo</i>,
resulting from the prolonged retention of the MAP@DOX NPs on the tumor
surface. Thus, this adhesive MAP NP-based spray therapeutic system
provides a promising approach for topical drug delivery in adjuvant
cancer therapy