Bioadhesive and conductive hydrogel-integrated brain-machine interfaces for conformal and immune-evasive contact with brain tissue

Polydopamine-mediated graphene oxide and nanohydroxyapatite-incorporated conductive scaffold with an immunomodulatory ability accelerates periodontal bone regeneration in diabetes

“…Because of the disordered immunity of diabetes, biomaterials with the abilities to regenerate new bone and regulate immunity are required. Mussel-inspired polydopamine (PDA) is considered to be a promising antioxidant that reduces oxidative stress through scavenging ROS and down-regulating inflammatory mediators [ [17] , [18] , [19] ]. Our recent study showed that a PDA-based conductive silk fiber path accelerates diabetic wound healing by promoting cell adhesion, alleviating inflammation, relieving oxidative stress, and remodeling the extracellular matrix (ECM) [ 20 ].…”

Hydrogel–Tissue Interface Interactions for Implantable Flexible Bioelectronics

“…The implanted device recorded the ECoG signal on the surface of brain tissue, avoiding physical damage that is usually caused by the penetration of rigid electrodes. 52 The capability to record neural signals and electrical stimulation by using implanted electrodes allows the establishment of direct communication between the brain and an artificial device. 55 Bioadhesive and ultrasoft hydrogels comprised of dopamine-functionalized PEDOT nanoparticles and a carrageenan interpenetrated PDA−PAAm network show a modulus of <1 kPa, matching that of the brain, a conductivity of 42 S m −1 , and low interfacial impedance.…”

“…55 Bioadhesive and ultrasoft hydrogels comprised of dopamine-functionalized PEDOT nanoparticles and a carrageenan interpenetrated PDA−PAAm network show a modulus of <1 kPa, matching that of the brain, a conductivity of 42 S m −1 , and low interfacial impedance. 52 The hydrogel is integrated with a patterned Au/polyimide thin film as electrodes attached on the dura mater on the primary visual cortex for recording in vivo electrocorticography (ECoG) signals. The SNR value of the ECoG signal recorded by hydrogel-integrated electrodes is better than that of the screw electrodes.…”

Natural polymer‐based adhesive hydrogel for biomedical applications

“…This bonding method is more stable than hydrogen bonding in water; thus, the catechol groups can replace the water molecules bound to the surface. However, in the presence of blood and body fluids, aggregated hydrogen bonding must be combined with other chemical strategies (such as covalent cross‐linking) to form stable adhesion [48].…”

“…Hydrogels can be tailored to achieve various cross-linking densities, mechanical properties, and porous structures through various cross-linking mechanisms and functional groups. A significant amount of research has proposed integrating functional components or chemically/biologically active systems to form functional hydrogels, such as self-healing materials [31,[34][35][36][37][38][39][40], conductive fillers [41][42][43][44][45][46][47][48][49][50][51], and adhesion groups.…”