An implantable MEMS micropump system for drug delivery in small animals

Abstract

We present the first implantable drug delivery system for controlled dosing, timing, and location in small animals. Current implantable drug delivery devices do not provide control over these factors or are not feasible for implantation in research animals as small as mice. Our system utilizes an integrated electrolysis micropump, is refillable, has an inert drug reservoir for broad drug compatibility, and is capable of adjustment to the delivery regimen while implanted. Electrochemical impedance spectroscopy (EIS) was used for characterization of electrodes on glass substrate and a flexible Parylene substrate. Benchtop testing of the electrolysis actuator resulted in flow rates from 1 to 34 μL/min on glass substrate and up to 6.8 μL/min on Parylene substrate. The fully integrated system generated a flow rate of 4.72 ± 0.35 μL/min under applied constant current of 1.0 mA while maintaining a power consumption of only ~3 mW. Finally, we demonstrated in vivo application of the system for anti-cancer drug delivery in mice.

Towards soft robotic devices for site-specific drug delivery

“…Such devices usually need an on-board power source (e.g. a battery), which significantly affects the overall size of the device and where it can be implanted in and around the body [20]. On the other hand, an osmotic micropump [21] does not require energy and this means that a drug delivery system based on an osmotic pump is much smaller and simpler than the actively operated mechanical displacement micropumps and electro and magneto-kinetic micropumps [22].…”

Approaches and Challenges of Engineering Implantable Microelectromechanical Systems (MEMS) Drug Delivery Systems for in Vitro and in Vivo Applications

“…One of the greatest advantages of BioMEMS in the treatment of chronic diseases is that, in addition to localized/targeted delivery, they are able to provide personalized drug delivery in the form of a continuous pulsatile drug release profile [2,39,40]. This personalized drug release profile is specifically designed to maximize the therapeutic effects of the drug while limiting the side effects associated with overdose in conventional drug therapies [40]. In order to perform this mode of treatment with patients, implantable BioMEMS must be able to remain operable for a long period of time such that long term personalized medication can be used to treat these chronic diseases.…”

“…A responsive drug delivery system would allow the drug dosage to be specifically tuned according to the type and state of the disease within the individual, providing personalized drug delivery, maximizing the therapeutic effects of the drugs and reducing the overdose induced side-effects [40]. These systems have biosensors which allow the BioMEMS drug delivery devices to evaluate the efficiency of the administered drug by monitoring specific marker molecules of the disease being treated [56].…”

Fluctuation in Blood Velocity under Applied Electromagnetic Pulse Fields

“…According to Lorentz principle, stimulating these fields lead to the appearance of a force along the fluid path [7,8]. Derived force can be employed for diagnosis and treatment in different ways such as drug delivery to injured organs, drug delivery with nano-particles for invaded cancerous cells, nanorobot navigators in local surgeries and many other applications [8][9][10][11][12]. In fact, in some cases lower velocity in drug delivery to injured locations makes it possible to have a lower drug concentration and lower treatment performance [8,13,14].…”

“…In fact, in some cases lower velocity in drug delivery to injured locations makes it possible to have a lower drug concentration and lower treatment performance [8,13,14]. Therefore, by using MHD pumps drug delivers to injured organs in higher speed and more efficiently [11]. Alongside with the application of MHD pumps for simulating, pumping, sorting and mixing fluids in channels, it will be used in industry for heating and circulation, buoyancy, and rotation of liquid metals [3,15].…”