A cyclically actuated electrolytic drug delivery device

Yi, Ying; Büttner, U.; Foulds, Ian G.

doi:10.1039/c5lc00703h

Cited by 26 publications

(40 citation statements)

References 43 publications

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“…5 Pumping the drug fluid and refilling the drug reservoir are based on the deflection of the PDMS membrane. 29 When the AC magnetic field is on, the induced voltage in the coil powers the electrode, driving the electrolytic reaction. The electrolysis induced-bubbles (hydrogen and oxygen from the separation of DI water) deform the PDMS membrane, pushing the drug towards the valve.…”

Section: Concept and Fabricationmentioning

confidence: 99%

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

Zaher

Yassine

et al. 2015

Biomicrofluidics

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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.

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Section: Concept and Fabricationmentioning

confidence: 99%

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

Zaher

Yassine

et al. 2015

Biomicrofluidics

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“…Currently, drug therapies are playing an important role for variety of biomedical applications and disease treatments. Conventional modes of drug administration including oral ingestions, eye drops, transdermal delivery and intravenous injections have been widely used 1 .However these conventional approaches have limitations in effectively delivering some special drug and new pharmaceutical agents 1 , and often cannot optimize the applied medication efficiency [2][3] . Chronic diseases, such as diabetes, usually require frequent injections, which lead to discomfort and trauma to patients.…”

Section: Introductionmentioning

confidence: 99%

“…Chronic diseases, such as diabetes, usually require frequent injections, which lead to discomfort and trauma to patients. In case of a potent drug, dosing must be precisely controlled within an effective therapeutic concentration range, which is difficult to achieve with conventional drug delivery approaches, frequently leading to overdose induced side effects [3][4] .…”

Section: Introductionmentioning

confidence: 99%

“…Once the device is implanted, additional surgical operations are not required for a long treatment period (months or even years). This reduces medical cost and patients' discomfort, maintains a desired drug concentration within the therapeutic window 3 , and improves the therapy's effectiveness. Implantable drug delivery devices are especially advantageous for treating chronic diseases, for example, brain tumors 5 .…”

Section: Introductionmentioning

confidence: 99%

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A remotely operated drug delivery system with dose control

Kosel

2017

Sensors and Actuators A: Physical

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On demand" implantable drug delivery systems can provide optimized treatments, due to their ability to provide targeted, flexible and precise dose release. However, two important issues that need to be carefully considered in a mature device include an effective actuation stimulus and a controllable dose release mechanism. This work focuses on remotely powering an implantable drug delivery system and providing a high degree of control over the released dose. This is accomplished by integration of a resonance-based wireless power transfer system, a constant voltage control circuit and an electrolytic pump. Upon the activation of the wireless power transfer system, the electrolytic actuator is remotely powered by a constant voltage regardless of movements of the device within an effective range of translation and rotation. This in turn contributes to a predictable dose release rate and greater flexibility in the positioning of external powering source. We have conducted proof-of-concept drug delivery studies using the liquid drug in reservoir approach and the solid drug in reservoir approach, respectively. Our experimental results demonstrate that the range of flow rate is mainly determined by the voltage controlled with a Zener diode and the resistance of the implantable device. The latter can be adjusted by connecting different resistors, providing control over the flow rate to meet different clinical needs. The flow rate can be maintained at a constant level within the effective movement range. When using a solid drug substitute with a low solubility, solvent blue 38, the dose release can be kept at 2.36 µg/cycle within the effective movement range by using an input voltage of 10V pp and a load of 1.5 kΩ, which indicates the feasibility and controllability of our system without any complicated closed-loop sensor.

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“…The field of drug delivery is of increasing interest amongst academic and industrial researchers seeking to optimize methods for localized, passive, smart, and remotely triggerable, on-demand drug delivery systems. [1][2][3][4][5][6][7][8][9][10][11] Functionalized organic composites that react to external stimuli such as heat, light, pH, ultrasound, or magnetic fields are of particular interest for a) A. Zaher and S. Li contributed equally to this work. b) Authors to whom correspondence should be addressed.…”

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confidence: 99%

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

Zaher

Wolf

et al. 2015

Biomicrofluidics

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Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices' drug diffusion rates are on the order of 0.5-2 lg/h for higher release rate designs, and 12-40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source. V C 2015 AIP Publishing LLC. [http://dx

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A cyclically actuated electrolytic drug delivery device

Cited by 26 publications

References 43 publications

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

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

A remotely operated drug delivery system with dose control

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

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