Cell-based drug delivery for combating bacteria: focus on refractory infections.

The escalating crisis of antimicrobial resistance and biofilm-associated infections has fundamentally compromised conventional anti-infective therapy. Current antimicrobial agents for refractory infections face critical limitations, including systemic toxicity, inadequate tissue penetration, and the rapid emergence of multidrug resistance (MDR). As a promising strategy, cell-based drug delivery systems (CDDS) leverage living cells or their bioactive derivatives as sophisticated carriers to overcome these barriers. By harnessing innate biological functions, such as prolonged circulation, immune evasion, and active targeting, CDDS enhances therapeutic efficacy in preclinical models against refractory infections. This review systematically elaborates on CDDS platforms engineered from erythrocytes, immune cells, platelets, and stem cells, highlighting their unique mechanisms and advantages in anti-infective drug delivery. Furthermore, we critically evaluate the translational progress and future potential of CDDS in combating refractory infections, particularly those involving multidrug-resistant bacteria and biofilm-associated pathogens.