Recently, Professor Xie Zhaoqian of the Ningbo Research Institute of Dalian University of Technology cooperated with Professor John A. Rogers of Northwestern University and Assistant Professor Jonathan T. Reeder of the University of Oregon to invent a bioresorbable flexible microfluidic control device. It achieves a block of nerve conduction through liquid vaporization cooling, and can be used as an alternative to opioid analgesics to achieve a precise analgesic effect without damage. The results of the research were published in Science.
Pain is one of the issues that require special attention in the clinic. The formation of reversible nerve blocks through local cooling can not only achieve the effect of eliminating pain as needed, but also completely avoid the side effects of taking opioids and other analgesics. Traditional local cooling technology requires the help of large medical equipment and implemented in specific environments, which is often difficult to achieve accurate cooling effects, and there are great limitations in practical applications.
In response to the above problems, the research team designed a flexible, self-winding (no suture-free), bioabsorbable peripheral nerve cooling microfluidic device that can provide accurate, minimally invasive cooling effects at any depth of living tissue. The flexible device integrates a microfluidic system and a circuit system to provide precise and continuous cooling in specific areas by controlling the flow rate and flow rate of the input fluid in the microfluidic system of the device, and by vaporizing the heat absorption of perfluoropentane liquid. The magnesium line temperature sensor with a snake-like morphology is distributed at the end of the device, and the temperature feedback is obtained in real time through the change of sensor resistance, which successfully realizes the accurate monitoring of the temperature. At the same time, the mechanical design of the multilayer structure with pre-tensioning allows the device to form a self-curling structure that can be tightly attached to the neural surface that needs to be cooled without stitching and can form a good force-heat interface. The device consists entirely of water-soluble materials that dissolve in the biological fluid of the subcutaneous tissue within a specified period of time according to individual requirements. This avoids the pain of additional demolition surgery and can well meet the patient’s analgesia needs over a long period of time, which has significant advantages over existing technologies and products.
Bioresorbable flexible cooler based on microfluidics that can accurately block nerves (Courtesy of Dalian University of Technology)
Based on the simulation and analysis of structural mechanics and heat transfer, the research team carried out the structural and temperature control optimization design. The device also achieves precise and non-destructive cooling of neural tissue, effectively blocking pain transmission.
Finite element simulation and experiment of cooling area (Courtesy of Dalian University of Technology)
Related animal experiments have confirmed that the device can achieve low temperature regulation in a short period of time and can well inhibit nerve activity. Long-term observations have shown that neural activity returns to normal quickly after rewarming without any side effects. The device also provides excellent on-demand analgesia for freely moving animal models. Through the relevant histological analysis of animal models, it was found that the cuff of the device could still be in close contact with the nerves after 6 months of implantation in the human body, showing extremely superior mechanical properties. At the same time, biological experiments have also verified that the device has good biocompatibility and absorption.
Experimental situation of cooling induced nerve block and analgesia (Courtesy of Dalian University of Technology)
This work demonstrates for the first time the successful application of bioresorbable implantable miniature flexible coolers in nerve block pain, which is of great guiding significance for future pain management research based on flexible medical devices. (Source: China Science Daily Sun Danning)
Related paper information:https://doi.org/10.1126/science.abl8532