Covalent Binding of Dexamethasone to Polyimide Improves Biocompatibility of Neural Implantable Devices
Journal article, 2025
Neural implants are widely used in prosthetic applications to interact with the peripheral nervous system, but their long-term functionality is compromised by foreign body reactions (FBR). Thanks to its high biocompatibility, polyimide poly (biphenyl dianhydride)-p-phenylenediamine (BPDA-PDA) represents a suitable material to fabricate ultrathin and ultra-flexible neural implants. This study explores the surface functionalization of BPDA-PDA, the electrically inert component of the neural implant. The novelty of this approach relies on the fact that dexamethasone (DEX covalently bound to BPDA-PDA, enabling its sustained release over a period of at least 9 weeks. In vitro assays demonstrate that this strategy reduce the production of pro-inflammatory markers in macrophages. In addition, the biocompatibility of the functionalized material has been ensured by evaluating the viability of dorsal root ganglia (DRG) neurons. Furthermore, in vivo implantation of DEX functionalized BPDA-PDA substrates shows a significant reduction in inflammatory cell infiltration and fibrotic capsule thickness formed around the devices. These findings suggest that local release of DEX from the electrically inactive scaffold of neural implants may enhance their long-term stability and performance by mitigating the FBR.
intraneural electrodes
surface chemistry
dexamethasone
drug delivery systems
foreign body reactions
neuroprostheses
Author
Giulia Turrin
University of Ferrara
Jose Crugeiras
Universitat Autonoma de Barcelona (UAB)
Chiara Bisquoli
University of Ferrara
Davide Barboni
University of Ferrara
Martina Catani
University of Ferrara
Bruno Rodríguez-Meana
Universitat Autonoma de Barcelona (UAB)
Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas
Rita Boaretto
University of Ferrara
Michele Albicini
University of Ferrara
Stefano Caramori
University of Ferrara
Claudio Trapella
University of Ferrara
Thomas Stieglitz
University of Freiburg
Yara Baslan
University of Freiburg
Hanna Karlsson-Fernberg
Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems
Fernanda L. Narvaez-Chicaiza
University of Freiburg
Edoardo Marchini
University of Ferrara
Alberto Cavazzini
University of Ferrara
Council for Agricultural Research and Economics (CREA)
Ruben López-Vales
Universitat Autonoma de Barcelona (UAB)
Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas
Maria Asplund
Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems
Xavier Navarro
Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas
Universitat Autonoma de Barcelona (UAB)
Stefano Carli
University of Ferrara
Advanced healthcare materials
2192-2640 (ISSN) 2192-2659 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Neurosciences
DOI
10.1002/adhm.202405004
PubMed
40528547