Microneedle-guided monitoring and therapy in chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) represents the most severe form of peripheral artery disease, with high risks of infection, tissue loss, amputation, and mortality. Continuous or high-frequency monitoring could improve early detection of deterioration between clinic visits, yet current perfusion tests are limited by variability and episodic use. This mini review focuses on microneedle-enabled access to interstitial fluid for trend-based monitoring and local therapy in CLTI. Evidence is synthesized linking oxygenation, lactate, and pH to ischemic pathophysiology and infection risk, and microneedle sensing approaches for these core markers are outlined. Local delivery design patterns that support staged care-stabilizing the microenvironment, controlling infection, and promoting regeneration-are summarized while maintaining sensing interpretability. Key translation barriers include drift and calibration during chronic wear, safety in fragile ischemic skin, and integration with clinical workflows. Minimally sufficient, trend-oriented sensing combined with phase-matched local interventions provides a pragmatic pathway toward clinically actionable "sense-treat" microneedle systems for CLTI.