Fabrication and characterization of implantable flushable electrodes for electric field‐mediated drug delivery in a brain tissue‐mimic agarose gel

Abstract

Every forty minutes, one person dies in the USA due to glioblastoma multiforme; a deadly form of brain cancer with an average five-year survival rate less than 3%. The current standard of care for treatment involves surgical resection of the accessible tumor followed by radiation therapy and concomitant chemotherapy. Despite their potency, delivering chemotherapeutic agents to the brain is limited by the highly selective blood-brain barrier, which prevents molecules >500 Da from reaching the brain. Other techniques, such as convection-enhanced delivery, controlled release by drug-loaded wafers or intracerebroventricular infusion have limited clinical utility due to unpredictable targeting and volume of drug distribution. We introduce a novel drug delivery technique that can use direct current electric fields to deliver charged chemotherapeutics to the site of brain parenchyma after tumor resection. We fabricate and characterize an implantable drug delivery system using flushable electrodes to deliver the charged chemotherapeutic or doxorubicin (+1) in a brain tissue-mimic agarose gel (0.2% w/v) model by electrophoresis. The optimized capillary-embedded electrode system exhibited a sustained movement of charged doxorubicin through nearly 3.5 mm in four hours, a distance for achieving effective intratumoral concentrations.

Carbohydrate based biomaterials for neural interface applications

“…Agarose gel matrix for drug encapsulation 221,255 implanted in the stroke core in mice. CS-A was found to act via FGF2 to potentiate NPC-mediated angiogenesis and vascular remodeling, blood flow recovery and sensorimotor recovery after injury (Fig.…”

“…The drug was loaded on a capillary-embedded electrode encased with flexible and transparent polydimethoxysilane (PDMS) and exhibited the sustained release of the drug in the brain phantom. 255 Another group fabricated an electroactive aniline–pentamer colloidal cryogel based on agarose, alginate and chitosan which was loaded with dexamethasone and released on demand upon an application of 0.5 V. 221 This electroactive carbohydrate polymer cryogel can be applied as a coating for neural recording and stimulating electrodes with drug eluting properties.…”