Within the IRC, we are researching two implantable devices. The first is an electrophoretic ion pump through which a drug solution is circulated and drug ions are discharged through an ion exchange membrane. The second is a fully polymeric delivery device in which the drug molecules are incorporated in the elastomer electrodes during manufacture.
The implantable devices transport drug ions by electrophoresis into the targeted treatment area. They can be implanted in the tumour area, which overcomes the significant hurdle of bypassing the blood-brain barrier. In addition, these devices enable predominantly dry delivery by transporting only the supramolecular vehicles and molecular cargo without a solvent. This enables high drug concentrations to be achieved with spatiotemporal control while avoiding the possibility of pressure build-up and edema in the targeted area.
In their simplest form, electrophoretic ion pumps are similar to microdialysis devices, but with two electrodes that drive drug transport from the internal reservoir to the brain, thereby enabling more powerful drug delivery. The key component is an ion exchange membrane through which the drug is transported and released. The IRC is developing implantable devices using biocompatible, printable polymers for validation in inoperable brain tumour animal models following extensive in vitro characterisation.
The IRC is also exploring the incorporation of on-board lactate sensors for the in-situ monitoring of tumours. This coupling of in-situ sensing will enable real time feedback on the efficacy of drug delivery, which in turn will help clinicians optimise the dosing. The ability to precisely control the spatiotemporal profile of chemotherapy with an implanted device would mark a step change in cancer treatment.
