Acupuncture Mechanics, Stimulation, and Cellular Serotonin Detection by a Magneto-Responsive Nanomesh Sensor

Acupuncture exerts its therapeutic effects through complex mechanical cues, including compressive forces from needle insertion and retention, and tensile stresses from extracellular matrix deformation during needle twisting. How these biomechanical stimuli regulate mast cell function at the molecular level remains poorly understood due to the lack of tools capable of replicating such multifaceted forces. Here, we report a magneto-responsive biosensor that enables multimodal simulation of stretching, compression, and combined loading in both static and cyclic modes. This allows for closely recapitulating the mechanical environment of mast cells during acupuncture, while simultaneously monitoring mechanically evoked cellular serotonin (5HT) release in real time. Using this sensor, we demonstrate that cyclic combined stimulation significantly amplifies cell responses by promoting both 5-HT release and intracellular biosynthesis. Furthermore, in vivo experiments at acupoints confirmed the "release-replenishment" phenomenon observed in vitro. Collectively, this study provides mechanistic insights into the molecular basis of acupuncture therapy and establishes a versatile tool for probing mechanobiological regulation in living systems.