Publications by authors named "Gelain F"

The use of self-assembling peptide hydrogels in the treatment of spinal cord and brain injuries, especially when combined with adult neural stem cells, has shown great potential. To advance tissue engineering, it is essential to understand the effect of mechanochemical signaling on cellular differentiation. The elucidation of the molecular interactions at the level of the neuronal membrane still represents a promising area of investigation for many drug delivery and tissue engineering applications.

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Piezoelectric materials can provide electrical stimulation without external chemical or physical support, opening new frontiers for future bioelectric therapies. Polyvinylidene fluoride (PVDF) possesses piezoelectricity and biocompatibility, making it an electroactive biomaterial capable of enhancing bioactivity through instantaneous electrical stimulation, which indicates significant potential in tissue engineering. In this study, we developed electroactive and biomimetic scaffolds made of electrospun PVDF and self-assembling peptides (SAPs) to enhance stem cell transplantation for spinal cord injury regeneration.

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Self-assembling peptides (SAPs) have gained significant attention in biomedicine because of their unique properties and ability to undergo molecular self-assembly driven by non-covalent interactions. By manipulating their composition and structure, SAPs can form well-ordered nanostructures with enhanced selectivity, stability and biocompatibility. SAPs offer advantages such as high chemical and biological diversity and the potential for functionalization.

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The development of three-dimensional (3D) biomaterials that mimic natural tissues is required for efficiently restoring physiological functions of injured tissues and organs. In the field of soft hydrogels, self-assembled peptides (SAPs) stand out as distinctive biomimetic scaffolds, offering tunable properties. They have garnered significant attention in nanomedicine due to their innate ability to self-assemble, resulting in the creation of fibrous nanostructures that closely mimic the microenvironment of the extracellular matrix (ECM).

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Spinal cord regeneration using stem cell transplantation is a promising strategy for regenerative therapy. Stem cells transplanted onto scaffolds that can mimic natural extracellular matrix (ECM) have the potential to significantly improve outcomes. In this study, we strived to develop a cell carrier by culturing neural stem cells (NSCs) onto electrospun 2D and 3D constructs made up of specific crosslinked functionalized self-assembling peptides (SAPs) featuring enhanced biomimetic and biomechanical properties.

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Article Synopsis
  • Biomaterials for tissue engineering need to resemble the native extracellular matrix in both structure and mechanical properties for effective implantation therapies.
  • Self-assembling peptides (SAPs) are promising materials but often produce soft hydrogels unsuitable for tougher tissues; chemical cross-linking is a common solution but can involve toxic or expensive agents.
  • The study introduces a novel, green method using microwave irradiation to enhance the stiffness and resilience of SAPs without compromising their biomimetic properties, suggesting a feasible approach for broader use in research and clinical applications.
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Molecular dynamics simulations, at different scales, have been exploited for investigating complex mechanisms ruling biologically inspired systems. Nonetheless, with recent advances and unprecedented achievements, the analysis of molecular dynamics simulations requires customized workflows. In 2018, we developed Morphoscanner to retrieve structural relations within self-assembling peptide systems.

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Self-assembling peptides (SAPs) have been increasingly studied as hydrogel-former gelators because they can create biocompatible environments. A common strategy to trigger gelation, is to use a pH variation, but most methods result in a change in pH that is too rapid, leading to gels with hardly reproducible properties. Here, we use the urea-urease reaction to tune gel properties, by a slow and uniform pH increase.

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Human pancreatic islets transplantation is an experimental therapeutic treatment for Type I Diabetes. Limited islets lifespan in culture remains the main drawback, due to the absence of native extracellular matrix as mechanical support after their enzymatic and mechanical isolation procedure. Extending the limited islets lifespan by creating a long-term culture remains a challenge.

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Antimicrobial peptides play a crucial role in innate immunity, whose components are mainly peptide-based molecules with antibacterial properties. Indeed, the exploration of the immune system over the past 40 years has revealed a number of natural peptides playing a pivotal role in the defence mechanisms of vertebrates and invertebrates, including amphibians, insects, and mammalians. This review provides a discussion regarding the antibacterial mechanisms of peptide-based agents and their structure-activity relationships (SARs) with the aim of describing a topic that is not yet fully explored.

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Translation of cell therapies into clinical practice requires the adoption of robust production protocols in order to optimize and standardize the manufacture and cryopreservation of cells, in compliance with good manufacturing practice regulations. Between 2012 and 2020, we conducted two phase I clinical trials (EudraCT 2009-014484-39, EudraCT 2015-004855-37) on amyotrophic lateral sclerosis secondary progressive multiple sclerosis patients, respectively, treating them with human neural stem cells. Our production process of a hNSC-based medicinal product is the first to use brain tissue samples extracted from fetuses that died in spontaneous abortion or miscarriage.

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Significant progress has been made in peptide self-assembly over the past two decades; however, the cross-linking of self-assembling peptides yielding better performing nanomaterials is still in its infancy. Indeed, self-assembling peptides (SAPs), relying only on non-covalent interactions, are mechanically unstable and susceptible to solvent erosion, greatly hindering their practical application. Herein, drawing inspiration from the biological functions of tyrosine, we present a photo-cross-linking approach for the cross-linking of a tyrosine-containing LDLK12 SAP.

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Tissue engineering (TE) strategies require the design and characterization of novel biomaterials capable of mimicking the physiological microenvironments of the tissues to be regenerated. As such, implantable materials should be biomimetic, nanostructured and with mechanical properties approximating those of the target organ/tissue. Self-assembling peptides (SAPs) are biomimetic nanomaterials that can be readily synthesized and customized to match the requirements of some TE applications, but the weak interactions involved in the self-assembling phenomenon make them soft hydrogels unsuited for the regeneration of medium-to-hard tissues.

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Three-dimensional (3D) cell cultures offer an unparalleled platform to recreate spatial arrangements of cells . 3D cell culture systems have gained increasing interest due to their evident advantages in providing more physiologically relevant information and more predictive data compared to their two-dimensional (2D) counterpart. Design and well-established fabrication of organoids (a particular type of 3D cell culture system) are nowadays considered a pivotal achievement for their ability to replicate cytoarchitecture and the functionalities of an organ.

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Self-assembling processes are ubiquitous phenomena that drive the organization and the hierarchical formation of complex molecular systems. The investigation of assembling dynamics, emerging from the interactions among biomolecules like amino-acids and polypeptides, is fundamental to determine how a mixture of simple objects can yield a complex structure at the nano-scale level. In this paper we present HyperBeta, a novel open-source software that exploits an innovative algorithm based on hyper-graphs to efficiently identify and graphically represent the dynamics of [Formula: see text]-sheets formation.

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Well-defined scaffold hydrogels made of self-assembling peptides have found their way into clinical products. By examining the properties and applications of two self-assembling peptides-EAK16 and RADA16-we highlight the potential for translating designer biological scaffolds into commercial products.

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Unlabelled: A patient affected by COVID-19 pneumonia may develop pulmonary hypertension (PH) and secondary right ventricular (RV) involvement, due to lung parenchymal and interstitial damage and altered pulmonary haemodynamics, even in non-advanced phases of the disease. This is a consequence of hypoxic vasoconstriction of the pulmonary circulation, the use of positive end-expiratory pressure (PEEP) in mechanical ventilation, pulmonary endothelial injury, and local inflammatory thrombotic and/or thromboembolic processes. We report the case of a young man admitted with a diagnosis of COVID-19 pneumoniae with PH unrelated to viral infection and in whom partial anomalous pulmonary venous drainage (PAPVD) was eventually diagnosed.

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Activated microglia/macrophages infiltration, astrocyte migration, and increased production of inhibitory chondroitin sulfate proteoglycans (CSPGs) are standard harmful events taking place after the spinal cord injuries (SCI). The gliotic scar, viz. the outcome of chronic SCI, constitutes a long-lasting physical and chemical barrier to axonal regrowth.

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Short peptides are ubiquitous in nature. They are found as hormones, pheromones, antibacterial and antifungal agents in innate immunity systems, toxins, and pesticides. But no one seriously considered that peptides could be useful as scaffold hydrogel materials.

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Extracellular matrix (ECM) consists of proteins, proteoglycans, and different soluble molecules. ECM provides structural support to mammalian cells. ECM is responsible for important cell functions, as well as assembling cells into various tissues and organs, regulating growth and cell-cell interaction.

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Self-assembling peptides are an exemplary class of supramolecular biomaterials of broad biomedical utility. Mechanistic studies on the peptide self-assembly demonstrated the importance of the oligomeric intermediates towards the properties of the supramolecular biomaterials being formed. In this study, we demonstrate how the overall yield of the supramolecular assemblies are moderated through subtle molecular changes in the peptide monomers.

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Supramolecular nanostructures formed through peptide self-assembly can have a wide range of applications in the biomedical landscape. However, they often lose biomechanical properties at low mechanical stress due to the non-covalent interactions working in the self-assembling process. Herein, we report the design of cross-linked self-assembling peptide hydrogels using a one-pot in situ gelation system, based on 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide/N-hydroxysulfosuccinimide (EDC/sulfo-NHS) coupling, to tune its biomechanics.

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