A self-powered controllable microneedle drug delivery system for rapid blood pressure reduction

Hypertensive emergency is a clinical syndrome characterized by abrupt and substantial elevation of blood pressure in hypertensive patients due to specific triggers, leading to potentially life-threatening consequences. Intravenous injection of sodium nitroprusside is commonly used to rapidly lower blood pressure. However, its specialized nature limits its applicability for first aid or self-help in emergency situations. To address this issue, we have developed a self-powered and controllable microneedle drug delivery system that is easy to use and effective for lowering blood pressure. The system mainly consists of two parts: a piezoelectric thin film selfpowered module made of polyvinylidene fluoride and carbon nanotubes, and a drug delivery module composed of polylactic acid-Au microneedles and polylactic acid-Au-polypyrrole microneedles. The results show that different pressures applied to the self-powered module generate different voltages, thereby controlling the drug release efficiency of the microneedles. Compared with conventional active devices, it exhibits a higher drug release rate and effectiveness. Furthermore, the system was successfully utilized to reduce and control blood pressure in spontaneously hypertensive rats. Compared with the injection of sodium nitroprusside, this system can more effectively lower and control blood pressure levels, and its biological safety has been verified. This study presents a controllable and user-friendly rapid blood pressure lowering system suitable for hypertensive emergencies, which has important clinical application prospects.