Sprayable antibacterial Persian gum-silver nanoparticle dressing for wound healing acceleration

Wound infection is considered a significant challenge in skin injuries. Sprayable antibacterial wound dressings are interesting alternatives to their traditional counterparts because of their facile preparation, ease-of-use, and the possibility of topical delivery of antibacterial materials. Herein, novel sprayable antibacterial dressings are formulated and reported. The dressings were developed by in-situ formation of Ag-nanoparticles (Ag-NPs) using Persian gum (PG) as a carbohydrate polymer. Several tests were conducted to investigate the effect of polymer concentration on the sprayablity, biocompatibility, and antibacterial activity of the dressings (PG/Ag-NPs). Results showed that formulations up to 2 wt.% PG/Ag-NPs could be sprayed properly and form intact films. Antibacterial evaluations also showed biocidal activity of 1% PG/Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus. Cytotoxicity and in vivo full-thickness wound healing evaluation confirmed that 1% PG/ Ag-NPs spray was safe and improved wound healing process. All the results confirmed the high potential of formulated sprayable dressings for wound repair.Peer reviewe

Bioinspired Processing:Complex Coacervates as Versatile Inks for 3D Bioprinting

3D bioprinting is a powerful fabrication technique in biomedical engineering, which is currently limited by the number of available materials that meet all physicochemical and cytocompatibility requirements for biomaterial inks. Inspired by the key role of coacervations in the extrusion and spinning of many natural materials, hyaluronic acid-chitosan complex coacervates are proposed here as tunable biomaterial inks. Complex coacervates are obtained through an associative liquid-liquid phase separation driven by electrostatic attraction between oppositely charged macromolecules. They offer bioactive properties as well as facile modulation of their mechanical properties through mild physicochemical changes in the environment, rendering them attractive for 3D bioprinting. Fine-tuning the salt concentration, pH, and molecular weight of the constituent polymers results in biomaterial inks that are printable in air and water. The biomaterial ink, initially a viscoelastic fluid, transitions into a viscoelastic solid upon printing due to dehydration (for printing in air) or due to a change in pH and ionic composition (for printing in water). Consequently, scaffolds printed using the complex coacervate inks are stable without the need for post-printing processing. Cell culture scaffolds fabricated in this way are cytocompatible and show long-term topological stability. These results pave the way to a new class of easy-to-handle tunable biomaterials for biofabrication

Effect of Dynamically Arrested Domains on the Phase Behavior, Linear Viscoelasticity and Microstructure of Hyaluronic Acid - Chitosan Complex Coacervates

Complex coacervates make up a class of versatile materials formed as a result of the electrostatic associations between oppositely charged polyelectrolytes. It is well-known that the viscoelastic properties of these materials can be easily altered with the ionic strength of the medium, resulting in a range of materials from free-flowing liquids to gel-like solids. However, in addition to electrostatics, several other noncovalent interactions could influence the formation of the coacervate phase depending on the chemical nature of the polymers involved. Here, the importance of intermolecular hydrogen bonds on the phase behavior, microstructure, and viscoelasticity of hyaluronic acid (HA)-chitosan (CHI) complex coacervates is revealed. The density of intermolecular hydrogen bonds between CHI units increases with increasing pH of coacervation, which results in dynamically arrested regions within the complex coacervate, leading to elastic gel-like behavior. This pH-dependent behavior may be very relevant for the controlled solidification of complex coacervates and thus for polyelectrolyte material design.</p

Protein by-products: Composition, extraction, and biomedical applications

info:eu-repo/semantics/publishe

Effect of Dynamically Arrested Domains on the Phase Behavior, Linear Viscoelasticity and Microstructure of Hyaluronic Acid – Chitosan Complex Coacervates

Complex coacervates make up a class of versatile materials formed as a result of the electrostatic associations between oppositely charged polyelectrolytes. It is well-known that the viscoelastic properties of these materials can be easily altered with the ionic strength of the medium, resulting in a range of materials from free-flowing liquids to gel-like solids. However, in addition to electrostatics, several other noncovalent interactions could influence the formation of the coacervate phase depending on the chemical nature of the polymers involved. Here, the importance of intermolecular hydrogen bonds on the phase behavior, microstructure, and viscoelasticity of hyaluronic acid (HA)–chitosan (CHI) complex coacervates is revealed. The density of intermolecular hydrogen bonds between CHI units increases with increasing pH of coacervation, which results in dynamically arrested regions within the complex coacervate, leading to elastic gel-like behavior. This pH-dependent behavior may be very relevant for the controlled solidification of complex coacervates and thus for polyelectrolyte material design