Electrophoretic drug delivery for seizure control

Abstract

An implantable microfluidic ion pump prevents seizures in a mice by delivery of inhibitory neurotransmitters to the seizure source.

Materials and Device Considerations in Electrophoretic Drug Delivery Devices

“…The motion of charged ions is described by the Nernst-Planck equation and combined with Poisson's equation, which relates the charge density to the external applied electric field, forms the governing equations for the computational model of the device (see Supporting Information). The computation domain consists of source and target solutions both of which have a length L of 100 µm, separated by an IEM with width L m of 10 µm, consistent with experimentally reported values for the dimensions of a microfluidic ion pump 4,5,11 . As for the boundary condition, the electrodes are considered to be blocking towards ions, while no additional restrictions on the flow of ions are imposed the source/IEM and IEM target interfaces.…”

“…Looking ahead, we see that the device parameters in terms of concentration for current electrophoretic drug delivery devices sit in the middle part of the contour plots. (Most commercially available ion exchange membrane materials typically have a fixed charge concentration in the range between 100-1000 mM 21 , whereas drug concentration commonly used in electrophoretic drug delivery devices ranges from 10-100 mM 5,22 ). One can increase the device performance by either pushing for higher fixed charge concentration, higher drug solubility, or higher concentration ratio between drug and ion exchange membrane with lower initial drug concentration.…”

“…4. Both the initial drug concentration C D and the fixed charge concentration in the IEM C IM were varied by three orders of magnitude (with C D ranging from 1 mM to 1 M, and C IM ranging from 10 mM to 1 M), a parameter space that is larger than in previous studies 5,21,22 . The contour plot for Q in Fig.…”

“…However, CED causes pressure increase in the targeted areas, leading to edema and disruption of adjacent neural networks 3 . Electrophoretic drug delivery devices have shown promise for a variety of eventual clinical applications in the treatment of neuropathic pain 4 and epilepsy 5 . In these devices, drug ions are transported by electrophoresis from an internal source reservoir through an ion exchange membrane into the targeted treatment area.…”

Foreign body reaction is triggeredin vivoby cellular mechanosensing of implants stiffer than host tissue

“…Medical implants have become an indispensable tool for a wide range of applications, including bladder control 11 , treatment of neurological disorders 12 , drug delivery 13 , and tissue repair 14 . Recent advances in fabrication techniques have allowed for the development of increasingly complex implants, capable of better integrating into the host tissue and much improved functionality.…”