Microfabricated nanopore device for sustained release of therapeutic agent
Inventors
Martin, Francis J. • Boiarski, Anthony A.
Assignees
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Publication Number
US-7955614-B2
Publication Date
2011-06-07
Expiration Date
Abstract
A drug delivery device that includes a capsule for implantation into the body; the capsule further includes a reservoir for containing a substance such as a therapeutic agent, at least one port for allowing the substance to diffuse from or otherwise exit the reservoir, and a nanopore membrane in communication with the capsule at or near the exit port for controlling the rate of diffusion of the substance from the exit port. The device also includes an optional screen for providing structural stability to the nanopore membrane and for keeping the pores of the nanopore membrane clear. One embodiment of the drug delivery device includes an osmotic engine internal to the device for creating fluid flow through the device.
Core Innovation
The invention relates to an implantable drug delivery device in which an implantable capsule has a fluid impermeable wall that defines a reservoir for containing a substance. The fluid impermeable wall comprises at least one port, and a nanopore membrane is in communication with the port, with pores dimensioned to control the rate of diffusion of the substance from the capsule and thereby control diffusion-driven release from the reservoir.
The nanopore membrane is implemented as a microfabricated nanopore membrane having an array of parallel channels, where the smallest dimension of the array is within a pore-dimension range. The pores are tailored to the molecular dimensions of the substance, including selecting pore sizes on the order of about 1 to 5 times the molecular dimensions, and this pore dimensioning is used to achieve near or substantially zero-order release kinetics over weeks to months.
To support sustained transport through the nanopore membrane, the device can include a structural support screen to prevent pore fouling and maintain pore patency. The device can further include an osmotic engine comprising a semi-permeable membrane and an osmotically active agent retained by a molecular-weight restriction to drive water flux through the nanopore channels, thereby boosting or priming release and maintaining channel patency.
Claims Coverage
The document provides two independent claims. Across these independent claims, the inventive features center on a fluid impermeable capsule reservoir, a port, and a microfabricated nanopore membrane with pores dimensioned to control diffusion rate from the port.
Nanopore membrane diffusion-controlled implantable capsule
An implantable capsule having a fluid impermeable wall defining a reservoir for containing a substance, the wall comprising at least one port, and a nanopore membrane in communication with the port, the membrane having pores dimensioned to control the rate of diffusion of the substance from the capsule.
Surgically implanting a diffusion-controlled nanopore device
A method comprising providing a device with a fluid impermeable capsule wall defining a reservoir for containing a therapeutic agent and having at least one port for allowing the therapeutic agent to diffuse from the reservoir, the capsule also comprising a nanopore membrane in communication with the port with pores dimensioned to control the rate of diffusion of the therapeutic agent from the exit port, and surgically implanting the device into the body.
The independent claim set consistently ties controlled release to a diffusion-regulating nanopore membrane in communication with a port in a fluid impermeable reservoir capsule, and the method claim further requires surgical implantation of the device into the body.
Stated Advantages
Controlled diffusion-based release of a substance or therapeutic agent from an implanted capsule.
Near or substantially zero-order release kinetics over weeks to months, achieved by pore-size dependent diffusion control.
Maintained pore patency with optional structural support screen to prevent pore fouling.
Boosted or primed release and maintenance of channel patency using an optional osmotic engine that drives net water flux through the nanopore channels.
Documented Applications
Implantable drug delivery of substances or therapeutic agents from a capsule reservoir using a nanopore membrane to control diffusion rate.
Controlled delivery of therapeutic agents to the body in a controlled manner by surgically implanting the described device.
Diffusion and release behavior characterization using glucose diffusion experiments showing approximately near-zero-order behavior for a selected pore size.
Sustained blood-level pharmacokinetics in rats using radiolabeled albumin and lysozyme with release kinetics dependent on nanopore pore size.
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