Yi Ying, Zaher Amir, Yassine Omar, Kosel Jurgen, Foulds Ian G
School of Engineering, University of British Columbia (UBC) , Kelowna, British Columbia V1V 1V7, Canada.
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.
Biomicrofluidics. 2015 Jul 22;9(5):052608. doi: 10.1063/1.4927436. eCollection 2015 Sep.
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 electrolysis-induced 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.
可植入式药物输送装置因其靶向和控释能力而变得颇具吸引力。目前，两个重要问题是功能寿命和药物的非受控扩散。在这项工作中，我们展示了一种结合电解泵和热响应阀的药物输送装置，二者均由电磁场（40.5 mT和450 kHz）远程控制。我们提出的装置展示了一种新颖的操作机制，用于采用储库中固体药物的长期治疗。我们的装置还可防止药物液体的不期望扩散。当电磁场开启时，电解产生的气泡将药物液体驱向由聚（N-异丙基丙烯酰胺）（PNIPAM）和铁微粒组成的PNIPAM阀。铁微粒产生的热量使PNIPAM收缩，导致阀门打开。当电磁场关闭时，PNIPAM开始膨胀。与此同时，气泡催化重组成水，降低泵腔内部压力，这导致新鲜液体从装置外部重新填充。包含一个催化重整器，可在阀门有限的关闭时间内实现更多液体的重新填充。重新填充药物储库的体液量可进一步溶解固体药物，形成用于下一剂的可再现药物溶液。通过反复开启和关闭电磁场，药物剂量可循环释放，并且装置的出口可得到有效控制。
