319,050 research outputs found
Progress and challenges of implantable neural interfaces based on nature-derived materials
No full textNeural interfaces are bioelectronic devices capable of stimulating a population of neurons or nerve fascicles and recording electrical signals in a specific area. Despite their success in restoring sensory-motor functions in people with disabilities, their long-term exploitation is still limited by poor biocompatibility, mechanical mismatch between the device and neural tissue and the risk of a chronic inflammatory response upon implantation.
In this context, the use of nature-derived materials can help address these issues. Examples of these materials, such as extracellular matrix proteins, peptides, lipids and polysaccharides, have been employed for decades in biomedical science. Their excellent biocompatibility, biodegradability in the absence of toxic compound release, physiochemical properties that are similar to those of human tissues and reduced immunogenicity make them outstanding candidates to improve neural interface biocompatibility and long-term implantation safety. The objective of this review is to highlight progress and challenges concerning the impact of nature-derived materials on neural interface design. The use of these materials as biocompatible coatings and as building blocks of insulation materials for use in implantable neural interfaces is discussed. Moreover, future perspectives are presented to show the increasingly important uses of these materials for neural interface fabrication and their possible use for other applications in the framework of neural engineering
L' ornitologo ticinese, ossia, Manuale descrittivo gli uccelli di stazione e di passaggio nel cantone Ticino : coll'elenco nominativo e sistematico di quelli d'Europa e della loro ordinaria dimora
No full text[Antonio Riva] ; raccomandata dal Consiglio cantonale di pubblica educazion
System for selective thermal inhibition of the activity of nerves and neuronal structures
No full textThe present invention relates to a system for slowing, inhibiting or blocking the activity of nerves and neuronal structures, useful for research purposes and for medical use by injection or surgical implantation in patients in need thereof, for example in the treatment of pain, muscle spasms and epilepsy
Recent Advances in Polymeric Drug Delivery Systems for Peripheral Nerve Regeneration
No full textWhen a traumatic event causes complete denervation, muscle functional recovery is highly compromised. A possible solution to this issue is the implantation of a biodegradable polymeric tubular scaffold, providing a biomimetic environment to support the nerve regeneration process. However, in the case of consistent peripheral nerve damage, the regeneration capabilities are poor. Hence, a crucial challenge in this field is the development of biodegradable micro- nanostructured polymeric carriers for controlled and sustained release of molecules to enhance nerve regeneration. The aim of these systems is to favor the cellular processes that support nerve regeneration to increase the functional recovery outcome. Drug delivery systems (DDSs) are interesting solutions in the nerve regeneration framework, due to the possibility of specifically targeting the active principle within the site of interest, maximizing its therapeutical efficacy. The scope of this review is to highlight the recent advances regarding the study of biodegradable polymeric DDS for nerve regeneration and to discuss their potential to enhance regenerative performance in those clinical scenarios characterized by severe nerve damage
Polysaccharide Layer-by-Layer Coating for Polyimide-Based Neural Interfaces
No full textImplantable flexible neural interfaces (IfNIs) are capable of directly modulating signals of the central and peripheral nervous system by stimulating or recording the action potential. Despite outstanding results in acute experiments on animals and humans, their long-term biocompatibility is hampered by the effects of foreign body reactions that worsen electrical performance and cause tissue damage. We report on the fabrication of a polysaccharide nanostructured thin film as a coating of polyimide (PI)-based IfNIs. The layer-by-layer technique was used to coat the PI surface due to its versatility and ease of manufacturing. Two different LbL deposition techniques were tested and compared: dip coating and spin coating. Morphological and physiochemical characterization showed the presence of a very smooth and nanostructured thin film coating on the PI surface that remarkably enhanced surface hydrophilicity with respect to the bare PI surface for both the deposition techniques. However, spin coating offered more control over the fabrication properties, with the possibility to tune the coating’s physiochemical and morphological properties. Overall, the proposed coating strategies allowed the deposition of a biocompatible nanostructured film onto the PI surface and could represent a valid tool to enhance long-term IfNI biocompatibility by improving tissue/electrode integration
I "mondi d'acqua" delle terre di Lombardia. Tra cultura materiale e universi simbolici
No full textIl successivo capitolo a opera di Elena Riva ci ricorda come “mondi
d’acqua” differenziati, caratterizzati da identità che si esprimono sul territorio attraverso simboli e metafore, si generino dal rapporto che ogni comunità stabilisce con questo elemento primario. La storia dell’acqua non può dunque essere affrontata se non in modo trasversale a tante discipline.
L’autrice esamina, in particolare, l’universo simbolico acquatico delle terre di Lombardia, con specifi co riferimento a Milano, dove tutt’oggi l’acqua possiede un legame speciale con la città e tutto il territorio circostante.
Questa lettura di lungo periodo viene scandita individuando quattro momenti specifici: la stagione che ha visto l’acqua come elemento mitico,la successiva fase che ha sperimentato un addomesticamento delle acque,
l’epoca “secca” e, infi ne, la riscoperta dell’acqua come comfort
Improved Physiochemical Properties of Chitosan@PCL Nerve Conduits by Natural Molecule Crosslinking
No full text: Nerve conduits may represent a valuable alternative to autograft for the regeneration of long-gap damages. However, no NCs have currently reached market approval for the regeneration of limiting gap lesions, which still represents the very bottleneck of this technology. In recent years, a strong effort has been made to envision an engineered graft to tackle this issue. In our recent work, we presented a novel design of porous/3D-printed chitosan/poly-ε-caprolactone conduits, coupling freeze drying and additive manufacturing technologies to yield conduits with good structural properties. In this work, we studied genipin crosslinking as strategy to improve the physiochemical properties of our conduit. Genipin is a natural molecule with very low toxicity that has been used to crosslink chitosan porous matrix by binding the primary amino group of chitosan chains. Our characterization evidenced a stabilizing effect of genipin crosslinking towards the chitosan matrix, with reported modified porosity and ameliorated mechanical properties. Given the reported results, this method has the potential to improve the performance of our conduits for the regeneration of long-gap nerve injuries
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