Formation of Monolithic Ion-Selective Transport Media Based on “Click” Cross-Linked Hyperbranched Polyglycerol

Abstract

In the emerging field of organic bioelectronics, conducting polymers and ion-selective membranes are combined to form resistors, diodes, transistors, and circuits that transport and process both electronic and ionic signals. Such bioelectronics concepts have been explored in delivery devices that translate electronic addressing signals into the transport and dispensing of small charged biomolecules at high specificity and spatiotemporal resolution. Manufacturing such “iontronic” devices generally involves classical thin film processing of polyelectrolyte layers and insulators followed by application of electrolytes. This approach makes miniaturization and integration difficult, simply because the ion selective polyelectrolytes swell after completing the manufacturing. To advance such bioelectronics/iontronics and to enable applications where relatively larger molecules can be delivered, it is important to develop a versatile material system in which the charge/size selectivity can be easily tailormade at the same time enabling easy manufacturing of complex and miniaturized structures. Here, we report a one-pot synthesis approach with minimal amount of organic solvent to achieve cationic hyperbranched polyglycerol films for iontronics applications. The hyperbranched structure allows for tunable pre multi-functionalization, which combines available unsaturated groups used in crosslinking along with ionic groups for electrolytic properties, to achieve a one-step process when applied in devices for monolithic membrane gel formation with selective electrophoretic transport of molecules.

Targeted Chemotherapy of Glioblastoma Spheroids with an Iontronic Pump

“…Further developments will be needed to optimize this basic technology, for example, to improve pore size of the CEM and to overcome steric hindrance or π-π-electron interactions between CEM and Gem molecules, that most likely underly increasing capillary channel resistance during extended operation. New ion exchange membranes or other fabrication technologies [13,35] may further reduce resistance build-up and provide greater stability and versatility. Longer term, we envision a broader application of OEIP technology, for example, including the treatment of surgically inoperable tumors.…”

Design and Operation of Hybrid Microfluidic Iontronic Probes for Regulated Drug Delivery

“…As a complement to our simulation studies, we developed a fabrication protocol for a hybrid microfluidic iontronic probe ( Figure ) following the design principles from the modeling above. The iontronic component at the tip of the capillary was fabricated, encapsulated, and sealed by repeated steps of lamination and UV patterning of a dry film photoresist (DFP, Ordyl SY355 (Elga Europe)), drop casting of the AEM (hyperbranched polyglycerol (HPG) functionalized with positive terminal groups (C‐HPG) [ 9,19,20 ] ), and placement of the capillary fiber (Figure 2b–d). Details about the fabrication protocol can be found in Figure S3 (Supporting Information).…”

Organic Bioelectronics for Neurotransmitter Release at the Speed of Life

“…An alternative group IEMs, based on hyperbranched polymers, addresses this issue by o ering a more porous structure. [90] Hyperbranched polyglycerol (HPG) can be can be crosslinked either by heat or UV and functionalized into polyelectrolytes, by the addition of either cationic groups for AEMs (C-HPG) or anionic groups for CEM (A-HPG). [90,24] The choice of material including the trade-o between selectivity and permeability is discussed in Chapter 4.…”