Approaches for drug delivery with intracortical probes.

Intracortical microprobes allow the precise monitoring of electrical and chemical signaling and are widely used in neuroscience. Microelectromechanical system (MEMS) technologies have greatly enhanced the integration of multifunctional probes by facilitating the combination of multiple recording electrodes and drug delivery channels in a single probe. Depending on the neuroscientific application, various assembly strategies are required in addition to the microprobe fabrication itself.

Drug release mechanisms of steroid eluting rings in cardiac pacemaker lead electrodes.

This paper reports on the drug release mechanisms of silicone structures with embedded steroids applied in pacing leads. Different derivatives of the steroid dexamethasone, which is associated with the reduction of acute stimulation thresholds, were evaluated together with different matrix based release control mechanisms with the target to potentially match optimal drug release rates during the first month after implantation. By incorporating dexamethasone-21-dihydrogen phosphate in silicone matrices in combination with release rate adaption layers, almost continuous release rates were obtained under physiological test settings.

An intra-cerebral drug delivery system for freely moving animals.

Microinfusions of drugs directly into the central nervous system of awake animals represent a widely used means of unravelling brain functions related to behaviour. However, current approaches generally use tethered liquid infusion systems and a syringe pump to deliver drugs into the brain, which often interfere with behaviour. We address this shortfall with a miniaturised electronically-controlled drug delivery system (20 × 17.

Osmotic micropumps for drug delivery.

This paper reviews miniaturized drug delivery systems applying osmotic principles for pumping. Osmotic micropumps require no electrical energy and consequently enable drug delivery systems of smallest size for a broad field of new applications. In contrast to common tablets, these pumps provide constant (zero-order) drug release rates.

Miniaturized osmotic pump for oromucosal drug delivery with external readout station.

We report on a miniaturized, exchangeable drug delivery cartridge for Parkinson's Disease which is integrated in a partial removable prosthesis. An osmotic pumping principle uses saliva to release constantly a separately stored drug to the buccal mucosa, thus avoiding first pass metabolism and drug plasma level fluctuations. Therapeutic relevant information and fill level of the cartridge can be determined before and after usage with an external readout station.