A new carbohydrate-based wound dressing fibre with superior absorption and antimicrobial potency

Preparation, characterization and biological evaluation of silver nanoparticles and drug loaded composites for wound dressings formed from Lallemantia royleana seeds' mucilage

After an injury, the wounds need to be covered with a dressing. Lack of absorptive potential and sticking of dressing with the wound causes pain and slows the healing process. The aim of this study was to develop wound dressings having more absorptive potential and less sticking with the wound. The hemicelluloses from Lallemantia royleana seeds possess desirable properties for a wound dressing. The hemicellulose was blended with chitosan/chitin and glutaraldehyde to enhance the absorptive properties of the hemicellulose through cross-linking. Two types of formulations incorporating silver nanoparticles and ciprofloxacin were prepared. The composites were characterized by elemental analysis, Fourier-transform infrared spectroscopy and scanning electron microscopy, and evaluated for their antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The dressings were subjected to in vivo studies on Albino rats. The dressings were found to be porous and the silver nanoparticles and drug particles were found to be uniformly distributed in the polymeric matrix. The composite containing ciprofloxacin released the drug in a sustained manner for 14-16 days. From extrapolation of the data, it was discovered that the formulation would release around 80% of ciprofloxacin in about two weeks. Silver-ciprofloxacin nano-composites exhibited comparable activity (zone of inhibition 19-30 mm) against E. coli to that of ciprofloxacin (standard, 21-35 mm) and relatively lower activity in case of S. aureus (zone of inhabitation 11-17 mm). The dressings did not stick to the wound site and the site remained wet during the healing process. Thus the use of hemicellulose from L. royleana seeds proved to be beneficial for preparing wound dressings with improved properties because of having high swelling index, porosity and spongy texture.

Multifunctional Photoactive Hydrogels for Wound Healing Acceleration

Light is an attractive tool that has a profound impact on modern medicine. Particularly, light-based photothermal therapy (PTT) and photodynamic therapy (PDT) show great application prospects in the prevention of wound infection and promoting wound healing. In addition, hydrogels have shown attractive advantages in the field of wound dressings due to their excellent biochemical effects. Therefore, multifunctional photoresponsive hydrogels (MPRHs) that integrate the advantages of light and hydrogels are increasingly used in biomedicine, especially in the field of wound repair. However, a comprehensive review of MPRHs for wound regeneration is still lacking. This review first focuses on various types of MPRHs prepared by diverse photosensitizers, photothermal agents (PHTAs) including transition metal sulfide/oxides nanomaterials, metal nanostructure-based PHTAs, carbon-based PHTAs, conjugated polymer or complex-based PHTAs, and/or photodynamic agents (PHDAs) such as ZnO-based, black-phosphorus-based, TiO₂-based, and small organic molecule-based PHDAs. We also then discuss how PTT, PDT, and photothermal/photodynamic synergistic therapy can modulate the microenvironments of bacteria to inhibit infection. Overall, multifunctional hydrogels with both therapeutic and tissue regeneration capabilities have been discussed and existing challenges, as well as future research directions in the field of MPRHs and their application in wound management are argued.

Silver-containing polysaccharide-based tricomponent antibacterial fibres for wound care applications

OBJECTIVE

Polysaccharide-based biomaterials are extensively used in wound care healing due to their unique liquid absorption, gelling properties and biocompatibility properties. They play an important role in controlling infections of highly exuding hard-to-heal wounds. The main objective of this study was to develop silver-containing polysaccharide-based tricomponent antibacterial fibres for use in these complex wounds.

METHOD

The fibres were developed by coating silver-containing alginate and psyllium fibres with hydrolysed chitosan. Dope solution containing alginate, psyllium and silver carbonate was extruded into a coagulation bath containing calcium chloride and hydrolysed chitosan. The developed fibres were tested for liquid absorption, swelling and antibacterial properties against a control fibre (of alginate and psyllium).

RESULTS

The developed fibres showed comparatively better liquid absorption, gelling and antibacterial properties than the control fibres.

CONCLUSION

The study concluded that developed fibres could be a preferred choice for application on hard-to-heal wounds with high levels of exudate, to support infection control and faster healing.

An injectable self-healing anesthetic glycolipid-based oleogel with antibiofilm and diabetic wound skin repair properties

Globally, wound infections are considered as one of the major healthcare problems owing to the delayed healing process in diabetic patients and microbial contamination. Thus, the development of advanced materials for wound skin repair is of great research interest. Even though several biomaterials were identified as wound healing agents, gel-based scaffolds derived from either polymer or small molecules have displayed promising wound closure mechanism. Herein, for the first time, we report an injectable and self-healing self-assembled anesthetic oleogel derived from glycolipid, which exhibits antibiofilm and wound closure performance in diabetic rat. Glycolipid derived by the reaction of hydrophobic vinyl ester with α-chloralose in the presence of novozyme 435 undergoes spontaneous self-assembly in paraffin oil furnished an oleogel displaying self-healing behavior. In addition, we have prepared composite gel by encapsulating curcumin in the 3D fibrous network of oleogel. More interestingly, glycolipid in its native form demoed potential in disassembling methicillin-resistant Staphylococcus aureus, methicillin-susceptible Staphylococcus aureus, and Pseudomonas aeruginosa biofilms. Both oleogel and composite gel enhanced the wound skin repair in diabetic induced Wistar rats by promoting collagen synthesis, controlling free radical generation and further regulating tissue remodeling phases. Altogether, the reported supramolecular self-assembled anesthetic glycolipid could be potentially used for diabetic skin wound repair and to treat bacterial biofilm related infections.

Morin incorporated polysaccharide-protein (psyllium-keratin) hydrogel scaffolds accelerate diabetic wound healing in Wistar rats

Chronic wounds cost several billion dollars of public healthcare spending annually and continue to be a persistent threat globally. Several treatment methods have been explored, and all of them involve covering up the wound with therapeutic dressings that reduce inflammation and accelerate the healing process. In this present study, morin (MOR) was loaded onto hydrogel scaffolds prepared from psyllium seed husk polysaccharide (PSH), and human hair keratins (KER) crosslinked with sodium trimetaphosphate. ATR-FTIR confirmed the presence of the constituent chemical ingredients. SEM images of the scaffold surface reveal a highly porous architecture, with about 80% porosity measured by liquid displacement measurement, irrespective of the morin concentration. Swelling assays carried out on the scaffolds portray an ability to absorb up to seven times their dry weight of fluids. This makes them attractive for guiding moist wound healing on medium exuding wounds. An Alamar blue assay of NIH/3T3 fibroblast cells shows that cell viability decreases in the first 24 h but recovers to 85% in comparison to a control after 48 h. SEM images of fibroblast cells grown on the scaffolds confirm cellular attachment. An in vivo diabetic wound healing study showed that PSH + KER + MOR scaffold treatment significantly reduced the re-epithelialization time (p < 0.01) and enhanced the rate of wound contraction (p < 0.001), by accelerating collagen synthesis in diabetic rats compared to controls.

Using oxidized amylose as carrier of linalool for the development of antibacterial wound dressing

This study aimed to prepare antibacterial wound dressings based on collagen and linalool/oxidized amylose inclusion complex. Encapsulation with oxidized amylose was used as an effective way to introduce linalool into collagen matrix. Our results showed that the content of linalool in the composite dressings was efficiently increased thanks to the solubilization effect of oxidized amyloses. The developed composite dressings possessed porous structure. They had abilities to keep the wound in moist environment and meanwhile prevent the excess exudates accumulation. The incorporation of linalool conferred the composite dressings with excellent antibacterial activities as expected. Moreover, the composite dressing with the highest content of linalool presented enhanced blood compatibility and good cell biocompatibility. This composite dressing effectively promoted granulation tissue formation and accelerated wound healing. It effectively prevented inflammation in regenerated skin tissue and scar formation too. Overall, the developed antibacterial wound dressings hold great potential for use in wound healing applications.

Isabgol–silk fibroin 3D composite scaffolds as an effective dermal substitute for cutaneous wound healing in rats

Psyllium husk based silk 3D scaffolds were developed via freeze drying method without adding any bioactive substances to enhance tissue repair during cutaneous wound healing in rats.

Facile strategy for the development of polyglucopyranose–silver hydrogel/films for antimicrobial applications

Development of silver nanoparticles entrapped hydrogels for antimicrobial applications.