Self-Propelled Active Photothermal Nanoswimmer for Deep-Layered Elimination of Biofilm In Vivo

Increasing
penetration of antibacterial agents into biofilm is
a promising strategy for improvement of therapeutic effect and slowdown
of the progression of antibiotic resistance. Herein, we design a near-infrared
(NIR) light-driven nanoswimmer (HSMV). Under NIR light irradiation,
HSMV performs efficient self-propulsion and penetrates into the biofilm
within 5 min due to photothermal conversion of asymmetrically distributed
AuNPs. The localized thermal (∼45 °C) and thermal-triggered
release of vancomycin (Van) leads to an efficient combination of photothermal
therapy and chemotherapy in one system. The active motion of HSMV
increases the effective distance of photothermal therapy (PTT) and
also improves the therapeutic index of the antibiotic, resulting in
superior biofilm removal rate (>90%) in vitro. Notably, HSMV can
eliminate S. aureus biofilms grown in vivo under
10 min of laser irradiation
without damage to healthy tissues. This work may shed light on therapeutic
strategies for in vivo treatment of biofilm-associated infections.