Near-infrared light-activated lidocaine microneedle patch for rapid local anesthesia.

RATIONALE: Effective local anesthesia with rapid onset and minimal invasiveness is essential for certain minor surgeries, such as aesthetic procedures, but remains difficult to achieve with conventional local anesthesia. METHODS: A photothermal-responsive microneedle system (LiH/MXene@MNs) was developed, consisting of lidocaine-loaded needle tips and a backing layer in which MXene was confined exclusively. This system employs a spatial design that separates the drug and photothermal components, allowing efficient drug delivery under short-term near-infrared (NIR) irradiation. Mechanical, optical, and histological assessments were performed to evaluate the system's properties. In vitro and in vivo studies were conducted to assess biosafety and invasiveness, while behavioral tests were performed in a rat plantar incision model to evaluate the onset and duration of anesthesia. RESULTS: The LiH/MXene@MNs system exhibited robust skin penetration and high drug-loading efficiency. Behavioral tests in a rat plantar incision model further verified that anesthesia onset was induced within 5 minutes and sustained for up to 60 minutes on this platform, comparable to that achieved with invasive injection. Additionally, the system exhibited minimal invasiveness and excellent biosafety, as demonstrated by both in vitro and in vivo studies. CONCLUSIONS: The LiH/MXene@MNs platform offers an efficient, minimally invasive, and safe alternative to traditional local anesthesia techniques. This approach holds strong potential for use in minimally invasive aesthetic procedures, providing a promising solution for rapid and effective pain management.