Stimuli-responsive microneedles: Engineered solutions for multifaceted diabetic wound healing

Diabetic wounds are among the most common complications in patients with diabetes, often occurring in the lower extremities and manifesting as diabetic foot ulcers. These wounds are often associated with issues such as infection, peripheral artery disease, hyperglycemia, and hypoxia, making them difficult to heal and prone to becoming chronic wounds. MNs enable painless, controlled transdermal drug delivery, overcoming limitations of traditional methods such as poor permeability and short drug duration. Stimuli-responsive microneedles targeting specific triggers have developed rapidly in recent years and are expected to contribute to the realization of precision medicine. Diabetic wounds are often accompanied by microenvironmental imbalance, and this complex wound milieu frequently causes them to progress into refractory wounds. Stimuli-responsive microneedles therefore represent a promising therapeutic strategy. Current studies in this field are still mainly limited to single-stimulus-responsive microneedles, whereas multifunctional microneedles capable of responding to multiple stimuli have not yet been fully developed. This review summarizes the research foundation and current progress of stimuli-responsive microneedles for the treatment of diabetic wounds, and further discusses the future prospects and potential directions of multi-stimuli-responsive microneedles. In addition, this review clarifies the conceptual boundary between truly stimuli-responsive microneedles and microenvironment-associated therapeutic platforms, compares major responsive strategies and microneedle platforms, and discusses key translational barriers including mechanical robustness, manufacturing scalability, cargo stability, model relevance, and regulatory considerations.