Peptide Materials

Over the past three decades, the field of peptide-based materials has been rapidly expanding and evolving, becoming a multidisciplinary area, with new developments and applications being consistently discovered. The purpose of this Peptide Materials Special Issue is to highlight research presented at the first Gordon Research Conference on Peptide Materials in January, 2023. Consequently, we invited eminent scientists with primary research interests in Peptide Materials to contribute original research articles or short reviews in this area. This thematic issue is focused on the materials aspects of peptides and their derivatives and mimics, including both fundamental research in peptide design, synthesis, assembly, micellization, gelation, and coacervation, as well as disparate technological applications, including functional materials for energy storage, catalysis, drug delivery, regenerative medicine, adhesion, protein purification, and nanotechnology. As peptides are composed of amino acids─the fundamental building blocks of proteins─they serve as a natural bridge between small-molecule supramolecular assemblies and large biomacromolecular constructs. Their ability to adopt well-defined secondary and tertiary structures, undergo hierarchical self-assembly, and exhibit tunable biochemical properties and distinct structural features highlights their importance and relevance within the broader landscape of biomacromolecular research. The peptide materials field has become a well-established, interdisciplinary area that attracts chemists, chemical engineers, material scientists, physicists, and biomedical engineers. The papers collected in this special issue demonstrate the growing recognition of peptides, polypeptides, proteins, and their derivatives and mimics as a versatile and critical class of biomacromolecules, poised to drive continued growth and innovation across diverse scientific and technological disciplines

Thermoresponsive Core-cross-linked Nanoparticles from HA‑<i>b</i>‑ELP Diblock Copolymers

Stabilization against the dilution-dependent disassembly of self-assembled nanoparticles is a requirement for in vivo application. Herein, we propose a simple and biocompatible cross-linking reaction for the stabilization of a series of nanoparticles formed by the self-assembly of amphiphilic HA-b-ELP block copolymers, through the alkylation of methionine residues from the ELP block with diglycidyl ether compounds. The core-cross-linked nanoparticles retain their colloidal properties, with a spherical core–shell morphology, while maintaining thermoresponsive behavior. As such, instead of a reversible disassembly when non-cross-linked, a reversible swelling of nanoparticles’ core and increase of hydrodynamic diameter are observed with lowering of the temperature

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-b-poly­(l-glutamic acid) (PTMC-b-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-b-poly­(ethylene oxide) PB-b-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-b-poly­(l-glutamic acid) (PTMC-b-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-b-poly­(ethylene oxide) PB-b-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-<i>b</i>-poly­(l-glutamic acid) (PTMC-<i>b</i>-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-<i>b</i>-poly­(ethylene oxide) PB-<i>b</i>-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-<i>b</i>-poly­(l-glutamic acid) (PTMC-<i>b</i>-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-<i>b</i>-poly­(ethylene oxide) PB-<i>b</i>-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-<i>b</i>-poly­(l-glutamic acid) (PTMC-<i>b</i>-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-<i>b</i>-poly­(ethylene oxide) PB-<i>b</i>-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Polymersomes in “Gelly” Polymersomes: Toward Structural Cell Mimicry

We demonstrate here the formation of compartmentalized polymersomes with an internal “gelly” cavity using an original and versatile process. Nanosize polymersomes of poly­(trimethylene carbonate)-<i>b</i>-poly­(l-glutamic acid) (PTMC-<i>b</i>-PGA), formed by a solvent displacement method are encapsulated with a rough “cytoplasm mimic” in giant polymersomes of poly­(butadiene)-<i>b</i>-poly­(ethylene oxide) PB-<i>b</i>-PEO by emulsion–centrifugation. Such a system constitutes a first step toward the challenge of structural cell mimicry with both “organelles” and “cytoplasm mimics”. The structure is demonstrated with fluorescence labeling and confocal microscopy imaging with movies featuring the motion of the inner nanosize polymersomes in larger vesicles. Without “cytoplasm mimic”, the motion was confirmed to be Brownian by particle tracking analysis. The inner nanosize polymersomes motion was blocked in the presence of alginate, but only hindered in the presence of dextran. With the use of such high molecular weight and concentrated polysaccharides, the crowded internal volume of cells, responsible for the so-called “macromolecular crowding” effect influencing every intracellular macromolecular association, seems to be efficiently mimicked. This study constitutes major progress in the field of structural biomimicry and will certainly enable the rise of new, highly interesting properties in the field of high-added value soft matter

Synthesis of Calibrated Poly(3,4-ethylenedioxythiophene) Latexes in Aqueous Dispersant Media

The synthesis of spherical poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles with a narrow size distribution was achieved in a dispersant aqueous medium. Various oxidants such as ammonium persulfate, iron(III) p-toluenesulfonate, and iron(III) trichloride were tested. A series of end-functionalized poly(ethylene oxide) (PEO) such as α-(3,4-ethylenedioxythiophene) PEO, α-(N-methyl pyrrole) PEO, α-(fluorene) PEO, α,ω-(N-methyl pyrrole) PEO, α,ω-(thiophene) PEO, and α,ω-(fluorene) PEO were compared as reactive stabilizers. The molar mass and the functionality of these reactive PEOs were found to be important parameters with respect to the control of particle size and size distribution. PEDOT samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), size exclusion chromatography (SEC), and conductivity measurements

Block Copolymer Vesicle Permeability Measured by Osmotic Swelling and Shrinking

Vesicle response to osmotic shock provides insight into membrane permeability, a highly relevant value for applications ranging from nanoreactor experimentation to drug delivery. The osmotic shock approach has been employed extensively to elucidate the properties of phospholipid vesicles (liposomes) and of varieties of polymer vesicles (polymersomes). This study seeks to compare the membrane response for two varieties of polymersomes, a comb-type siloxane surfactant, poly(dimethylsiloxane)-g-poly(ethylene oxide) (PDMS-g-PEO), and a diblock copolymer, polybutadiene-b-poly(ethylene oxide) (PBut-b-PEO). Despite similar molecular weights and the same hydrophilic block (PEO), the two copolymers possess different hydrophobic blocks (PBut and PDMS) and corresponding glass transition temperatures (−31 and −123 °C, respectively). Dramatic variations in membrane response are observed during exposure to osmotic pressure differences, and values for polymer membrane permeability to water are extracted. We propose an explanation for the observed phenomena based on the respective properties of the PBut-b-PEO and PDMS-g-PEO membranes in terms of cohesion, thickness, and fluidity