A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

Abstract

Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysisinduced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve's closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled. V C 2015 AIP Publishing LLC.

A single magnetic nanocomposite cilia force sensor

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Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

“…These microgels can respond to stimuli such as temperature, pH, light and electric fields23456. Due to their distinct properties, responsive microgels have been employed in various applications including sensing, catalysis, drug delivery, optical devices, cell attachment and culturing, radiotherapy and optics789101112.…”

Microfabricated Drug Delivery Devices: Design, Fabrication, and Applications

“…[78][79][80][81] They could be fabricated into different functional components for a device such as valves, [82][83][84] gating membranes, [51,85] channels, and hinges [86,87] or serve as drug depots, [79,88] which can trigger and stop drug flux in response to environmental stimuli like pH, temperature, biological molecules, light, electromagnetic fields. [78][79][80][81] They could be fabricated into different functional components for a device such as valves, [82][83][84] gating membranes, [51,85] channels, and hinges [86,87] or serve as drug depots, [79,88] which can trigger and stop drug flux in response to environmental stimuli like pH, temperature, biological molecules, light, electromagnetic fields.…”