Micellization of Lipopeptides Containing Toll-like Receptor Agonist and Integrin Binding Sequences.

Short bioactive peptide sequences are of great interest in biomaterials development. We investigate the self-assembly of a lipopeptide containing both the highly cationic CSK toll-like receptor agonist hexapeptide sequence and RGDS integrin-binding motif, i.e.

Self-assembly, cytocompatibility, and interactions of desmopressin with sodium polystyrene sulfonate.

Peptide-polymer systems hold strong potential for applications in nanotherapeutics. Desmopressin, a synthetic analogue of the antidiuretic hormone arginine vasopressin, may serve as a valuable case of study in this context since it is a first-line treatment for disorders affecting water homeostasis, including diabetes insipidus. It also has an established use as a hemostatic agent in von Willebrand disease, and recently, its repurposing has been suggested as a neoadjuvant in the treatment of certain types of cancer.

Interaction of Arginine-Rich Surfactant-like Peptide Nanotubes with Liposomes.

The interaction of the surfactant-like peptide (SLP) RL bearing three cationic arginine residues with model liposomes is investigated in aqueous solution at various pH values, under conditions for which the SLP self-assembles into nanotubes. The structure of liposomes of model anionic lipid DPPG [1,2-dipalmitoyl--glycero-3-phospho-rac-(1-glycerol)], or zwitterionic lipid DPPE [1,2-dipalmitoyl--glycero-3-phosphoethanolamine] is probed using small-angle X-ray scattering and cryogenic-transmission electron microscopy. The unilamellar vesicles of DPPG are significantly restructured in the presence of RL, especially at low pH, and multilamellar vesicles of DPPE are also restructured under these conditions.

Harnessing Efficient ROS Generation in Carbon Dots Derived from Methyl Red for Antimicrobial Photodynamic Therapy.

The emergence of drug-resistant pathogenic microorganisms has become a public health concern, with demand for strategies to suppress their proliferation in healthcare facilities. The present study investigates the physicochemical and antimicrobial properties of carbon dots (CD-MR) derived from the methyl red azo dye. The morphological and structural analyses reveal that such carbon dots present a significant fraction of graphitic nitrogen in their structures, providing a wide emission range.

Heterologous DNA Prime- Subunit Protein Boost with Chikungunya Virus E2 Induces Neutralizing Antibodies and Cellular-Mediated Immunity.

Chikungunya virus (CHIKV) has become a significant public health concern due to the increasing number of outbreaks worldwide and the associated comorbidities. Despite substantial efforts, there is no specific treatment or licensed vaccine against CHIKV to date. The E2 glycoprotein of CHIKV is a promising vaccine candidate as it is a major target of neutralizing antibodies during infection.

DNA-templated self-assembly of bradykinin into bioactive nanofibrils.

Bradykinin (BK) is a peptide hormone that plays a crucial role in blood pressure control, regulates inflammation in the human body, and has recently been implicated in the pathophysiology of COVID-19. In this study, we report a strategy for fabricating highly ordered 1D nanostructures of BK using DNA fragments as a template for self-assembly. We have combined synchrotron small-angle X-ray scattering and high-resolution microscopy to provide insights into the nanoscale structure of BK-DNA complexes, unveiling the formation of ordered nanofibrils.

Modification of the Linker Amino Acid in the Cell-Penetrating Peptide NickFect55 Leads to Enhanced pDNA Transfection for In Vivo Applications.

Despite numerous efforts over the last three decades, nucleic acid-based therapeutics still lack delivery platforms in the clinical stage. Cell-penetrating peptides (CPPs) may offer solutions as potential delivery vectors. We have previously shown that designing a "kinked" structure in the peptide backbone resulted in a CPP with efficient in vitro transfection properties.

Nanostructure Formation and Cell Spheroid Morphogenesis of a Peptide Supramolecular Hydrogel.

Peptide-based hydrogels have attracted much attention due to their extraordinary applications in biomedicine and offer an excellent mimic for the 3D microenvironment of the extracellular matrix. These hydrated matrices comprise fibrous networks held together by a delicate balance of intermolecular forces. Here, we investigate the hydrogelation behavior of a designed decapeptide containing a tetraleucine self-assembling backbone and fibronectin-related tripeptides near both ends of the strand.

Amyloid-like Self-Assembly of a Hydrophobic Cell-Penetrating Peptide and Its Use as a Carrier for Nucleic Acids.

Cell-penetrating peptides (CPPs) are a topical subject potentially exploitable for creating nanotherapeutics for the delivery of bioactive loads. These compounds are often classified into three major categories according to their physicochemical characteristics: cationic, amphiphilic, and hydrophobic. Among them, the group of hydrophobic CPPs has received increasing attention in recent years due to toxicity concerns posed by highly cationic CPPs.

Methods for Small-Angle Scattering Measurements on Peptiplexes of DNA with Cell-Penetrating Peptides.

Peptiplexes are soft biomaterials formed through the noncovalent association between cell-penetrating peptides and nucleic acids. Although internalization often involves electrostatic anchoring followed by endocytosis, the mode of action of these transporters remains elusive in many cases, and proper understanding of mechanisms behind their penetrating capabilities necessarily entails structural data at the nanoscopic scale. In this chapter, we examine the structural landscape of peptiplexes, emphasizing the complex behavior of these polyelectrolyte self-assemblies and how supramolecular order impacts their translocation efficiency.

Microfluidic encapsulation of nanoparticles in alginate microgels gelled via competitive ligand exchange crosslinking.

Efficient delivery of nanometric vectors complexed with nanoparticles at a target tissue without spreading to other tissues is one of the main challenges in gene therapy. One means to overcome this problem is to confine such vectors within microgels that can be placed in a target tissue to be released slowly and locally. Herein, a conventional optical microscope coupled to a common smartphone was employed to monitor the microfluidic production of monodisperse alginate microgels containing nanoparticles as a model for the encapsulation of vectors.

Self-assembly and intracellular delivery of DNA by a truncated fragment derived from the Trojan peptide Penetratin.

Penetratin is a short Trojan peptide that attracts great interest in biomedical research for its capacity to translocate biological membranes. Herein, we study in detail both self-assembly and intracellular delivery of DNA by the heptamer KIWFQNR, a truncated peptide derived from Penetratin. This shortened sequence possesses a unique design with bolaamphiphilic characteristics that preserves the longest noncationic amino acid portion found in Penetratin.

Amphipathic design dictates self-assembly, cytotoxicity and cell uptake of arginine-rich surfactant-like peptides.

Amphiphilicity is the most critical parameter in the self-assembly of surfactant-like peptides (SLPs), regulating the way by which hydrophobic attraction holds peptides together. Its effects go beyond supramolecular assembly and may also trigger different cell responses of bioactive peptide-based nanostructures. Herein, we investigate the self-assembly and cellular effects of nanostructures based on isomeric SLPs composed by arginine (R) and phenylalanine (F).

Model self-assembling arginine-based tripeptides show selective activity against Pseudomonas bacteria.

Three model arginine-rich tripeptides RXR (X = W, F or non-natural residue 2-napthylalanine) were investigated as antimicrobial agents, with a specific focus to target Pseudomonas aeruginosa through membrane lysis. Activity against biofilms was related to binding of the second messenger molecule, nucleotide bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). Strong selective activity against P.

Nanoscopic Structure of Complexes Formed between DNA and the Cell-Penetrating Peptide Penetratin.

One of the most remarkable examples of cell-penetrating peptides (CPPs) is , a 16-mer fragment derived from the homeobox. Understanding the structure of /DNA complexes is a key factor for the successful design of new vectors for gene delivery and may assist in optimizing molecular carriers based on CPPs. Herein, we present a comprehensive study on the nanoscale structure of noncovalent complexes formed between and DNA.

β-sheet assembly in amyloidogenic glutamic acid nanostructures: Insights from X-ray scattering and infrared nanospectroscopy.

Glutamic acid-rich peptides are crucial to a variety of biological processes, including glutamatergic neurotransmission and immunological defense. Glutamic acid sequences often exhibit unusual organization into β -type sheets, where bifurcated H bonds formed between glutamic acid side chains and NH in amide bonds on adjacent β-strands play a paramount role for stabilizing the molecular assembly. Herein, we investigate the self-assembly and supramolecular structure of simplified models consisting of alternating glutamic acid/phenylalanine residues.