TY - JOUR
T1 - Injectable ionic hydrogel conductors
T2 - Advancing material design to transform cardiac pacing
AU - Rodriguez-Rivera, Gabriel J.
AU - Post, Allison
AU - John, Mathews
AU - Bashe, Derek
AU - Xu, Fei
AU - Larue, Trace
AU - Nkansah, Abbey
AU - Wancura, Megan
AU - Chwatko, Malgorzata
AU - Waldron, Christina
AU - Kalkunte, Nikhith
AU - Zoldan, Janet
AU - Arseneault, Mathieu
AU - Elgalad, Abdou
AU - Rausch, Manuel K.
AU - Razavi, Mehdi
AU - Cosgriff-Hernandez, Elizabeth
N1 - Publisher Copyright:
© 2025 Elsevier Ltd
PY - 2025/6
Y1 - 2025/6
N2 - Direct pacing of the mid myocardium where re-entry originates can be used to prevent ventricular arrhythmias and circumvent the need for painful defibrillation or cardiac ablation. However, there are no pacing electrodes small enough to navigate the coronary veins that cross these culprit scar regions. To address this need, we have developed an injectable ionically conductive hydrogel electrode that can fill the epicardial coronary veins and transform them into flexible electrodes. A new hydrogel chemistry based on a polyether urethane diacrylamide macromer was developed that matches myocardial stiffness and is resistant to hydrolysis. Conductivity was imparted using ionic precursor solutions with values in the range of 2-3X of native myocardium that was retained after implantation. Ionic hydrogel electrodes provided stable electrical stimuli over many cycles and across a substantial length of the cardiac vein. Rapid in situ cure was achieved with redox initiation after injection from a double-barrel syringe with a mixing head. An ex vivo porcine model was used to identify the requisite viscosity and cure rate for hydrogel retention and homogeneity. Finally, successful in vivo deployment and pacing in a porcine model demonstrated that the ionic hydrogel electrode filled the anterior interventricular vein to depths far more distal and refined than current technologies. Collectively, these studies demonstrate the potential of this injectable ionic hydrogel electrode to pace previously inaccessible mid-myocardial tissue and pave the pathway for painless defibrillation.
AB - Direct pacing of the mid myocardium where re-entry originates can be used to prevent ventricular arrhythmias and circumvent the need for painful defibrillation or cardiac ablation. However, there are no pacing electrodes small enough to navigate the coronary veins that cross these culprit scar regions. To address this need, we have developed an injectable ionically conductive hydrogel electrode that can fill the epicardial coronary veins and transform them into flexible electrodes. A new hydrogel chemistry based on a polyether urethane diacrylamide macromer was developed that matches myocardial stiffness and is resistant to hydrolysis. Conductivity was imparted using ionic precursor solutions with values in the range of 2-3X of native myocardium that was retained after implantation. Ionic hydrogel electrodes provided stable electrical stimuli over many cycles and across a substantial length of the cardiac vein. Rapid in situ cure was achieved with redox initiation after injection from a double-barrel syringe with a mixing head. An ex vivo porcine model was used to identify the requisite viscosity and cure rate for hydrogel retention and homogeneity. Finally, successful in vivo deployment and pacing in a porcine model demonstrated that the ionic hydrogel electrode filled the anterior interventricular vein to depths far more distal and refined than current technologies. Collectively, these studies demonstrate the potential of this injectable ionic hydrogel electrode to pace previously inaccessible mid-myocardial tissue and pave the pathway for painless defibrillation.
KW - Arrhythmias
KW - Biomaterials
KW - Conductive
KW - Hydrogels
KW - Injectable
KW - Pacing
UR - http://www.scopus.com/inward/record.url?scp=85214681529&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85214681529&partnerID=8YFLogxK
U2 - 10.1016/j.biomaterials.2024.123071
DO - 10.1016/j.biomaterials.2024.123071
M3 - Article
AN - SCOPUS:85214681529
SN - 0142-9612
VL - 317
JO - Biomaterials
JF - Biomaterials
M1 - 123071
ER -