Chronic non-healing wounds negatively impact quality of life and are a significant financial drain on health systems. The risk of infection that exacerbates comorbidities in patients necessitates regular application of wound care. Understanding the mechanisms underlying impaired wound healing are therefore a key priority to inform effective new-generation treatments.
View Article and Find Full Text PDFis one of the most common pathogens encountered in clinical wound infections. Clinical studies have shown that infection results in a larger wound area, inhibiting healing, and a high prevalence of antimicrobial resistance. Hydroxypyridinone-derived iron chelator Deferiprone (Def) and heme analogue Gallium-Protoporphyrin (GaPP) in a chitosan-dextran hydrogel (Chitogel) have previously been demonstrated to be effective against PAO1 and clinical isolates of in vitro.
View Article and Find Full Text PDFChimeric antigen receptor (CAR)-T cell immunotherapy is a novel treatment that genetically modifies the patients' own T cells to target and kill malignant cells. However, identification of tumour-specific antigens expressed on multiple solid cancer types, remains a major challenge. P2X purinoceptor 7 (P2X7) is a cell surface expressed ATP gated cation channel, and a dysfunctional version of P2X7, named nfP2X7, has been identified on cancer cells from multiple tissues, while being undetectable on healthy cells.
View Article and Find Full Text PDFBackground: Electrospun fibers are widely studied in regenerative medicine for their ability to mimic the extracellular matrix (ECM) and provide mechanical support. In vitro studies indicated that cell adhesion and migration is superior on smooth poly(L-lactic acid) (PLLA) electrospun scaffolds and porous scaffolds once biofunctionalized with collagen.
Methods: The in vivo performance of PLLA scaffolds with modified topology and collagen biofunctionalization in full-thickness mouse wounds was assessed by cellular infiltration, wound closure and re-epithelialization and ECM deposition.
Over the past two decades significant technical advancement in the field of western blotting has been made possible through the utilization of microfluidic technologies. In this review we provide a critical overview of these advancements, highlighting the advantages and disadvantages of each approach. Particular attention is paid to the development of now commercially available systems, including those for single cell analysis.
View Article and Find Full Text PDFFundamental knowledge about cell-surface interactions can be applied in the development of wound dressings and scaffolds to encourage wounds to heal. As surfaces produced with acid-functionalised monomers encourage keratinocyte adhesion, proliferation and migration, whilst amine functionalisation enhances fibroblast proliferation and migration in vitro, standard care wound dressings were plasma-coated with either acrylic acid or allylamine and applied to 6 mm excisional wounds on the backs of mice to test their effectiveness in vivo. At day 3, the rate of wound healing was increased in mice treated with dressings that were plasma-coated with allylamine compared to uncoated dressings, with a significantly reduced wound area.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
January 2023
Healing of cutaneous wounds is a fundamental process required to re-establish tissue integrity, repair skin barrier function, and restore skin homeostasis. Chronic wound infection, exacerbated by the growing development of resistance to conventional therapies, hinders the skin repair process and is a serious clinical problem affecting millions of people worldwide. In the past decade, the use of antimicrobial peptides (AMPs) has attracted increasing attention as a potential novel strategy for the treatment of chronic wound infections due to their unique multifaceted mechanisms of action, and AMPs have been demonstrated to function as potent host-defense molecules that can control microbial proliferation, modulate host-immune responses, and act as endogenous mediators of wound healing.
View Article and Find Full Text PDFThere has been little understanding of acidification functionality in wound healing, highlighting the need to study the efficacy of wound acidification on wound closure and cellular activity in non-infected wounds. This study is focused on establishing the healing potential of wound acidification in non-infected wounds. Acidic buffers, constituting either phosphoric or citric acid, were employed to modify the physiological pH of non-infected full-thickness excisional murine wounds.
View Article and Find Full Text PDFAntibacterial treatment that provides on-demand release of therapeutics that can kill a broad spectrum of pathogens while maintaining long-term efficacy and without developing resistance or causing side effects is urgently required in clinical practice. Here, we demonstrate the development of a multistimuli-responsive hydrogel, prepared by cross-linking -isopropylacrylamide with acrylic acid and loaded with ultrasmall silver nanoparticles (AgNPs), offering the on-demand release of Ag ions triggered by changes in the wound microenvironment. We demonstrate that this dual-responsive hydrogel is highly sensitive to a typical wound pH and temperature change, evidenced by the restricted release of Ag ions at acidic pH (<5.
View Article and Find Full Text PDFMacrophages are key immune cells that respond to infections, and modulate pathophysiological conditions such as wound healing. By possessing phagocytic activities and through the secretion of cytokines and growth factors, macrophages are pivotal orchestrators of inflammation, fibrosis, and wound repair. Macrophages orchestrate the process of wound healing through the transitioning from predominantly pro-inflammatory (M1-like phenotypes), which present early post-injury, to anti-inflammatory (M2-like phenotypes), which appear later to modulate skin repair and wound closure.
View Article and Find Full Text PDFThe restoration of an intact epidermal barrier after wound injury is the culmination of a highly complex and exquisitely regulated physiological process involving multiple cells and tissues, overlapping dynamic events and protein synthesis and regulation. Central to this process is the cytoskeleton, a system of intracellular proteins that are instrumental in regulating important processes involved in wound repair including chemotaxis, cytokinesis, proliferation, migration, and phagocytosis. One highly conserved family of cytoskeletal proteins that are emerging as major regulators of actin and microtubule nucleation, polymerization, and stabilization are the formins.
View Article and Find Full Text PDFTLR4 plays a pivotal role in orchestrating inflammation and tissue repair. Its expression has finally been balanced to initiate the early, robust immune response necessary for efficient repair without excessively amplifying and prolonging inflammation, which impairs healing. Studies show Flightless I (Flii) is an immunomodulator that negatively regulates macrophage TLR4 signalling.
View Article and Find Full Text PDFStrategies that alter the pH of wounds to improve healing outcomes are an emerging area of interest. Currently, there is limited understanding of the effect of hydrogen (H) on the functionality of skin cells during proliferation and migration, highlighting the need for research to determine the effect of pH during wound healing. This study aimed to determine the effect of acidification on the metabolic activity and migration of human immortalized keratinocytes (HaCaT) and human foreskin fibroblasts (HFF).
View Article and Find Full Text PDFCellular mechanisms and/or microbiological interactions which contribute to chronic diabetes related foot ulcers (DRFUs) were explored using serially collected tissue specimens from chronic DRFUs and control healthy foot skin. Total RNA was isolated for next-generation sequencing. We found differentially expressed genes (DEGs) and enriched hallmark gene ontology biological processes upregulated in chronic DRFUs which primarily functioned in the host immune response including: (i) Inflammatory response; (ii) TNF signalling via NFKB; (iii) IL6 JAK-STAT3 signalling; (iv) IL2 STAT5 signalling and (v) Reactive oxygen species.
View Article and Find Full Text PDFWound healing is a complex and dynamic process that requires intricate synchronization between multiple cell types within appropriate extracellular microenvironment. Wound healing process involves four overlapping phases in a precisely regulated manner, consisting of hemostasis, inflammation, proliferation, and maturation. For an effective wound healing, all four phases must follow in a sequential pattern within a time frame.
View Article and Find Full Text PDFBackground: Antimicrobial silver has had a role in wound antisepsis throughout history and, with the rise in acquired antibiotic resistance, silver dressings are once again commonly used. Issues with silver dressings include the important environmental consideration of nanoparticle manufacture, and the significant financial cost of these products. One solution to these problems may be to adopt an opened-but-unused model of wound care whereby dressing materials are used in piecemeal fashion and excess stored in between dressing changes.
View Article and Find Full Text PDFWound healing requires a complex cascade of highly controlled and conserved cellular and molecular processes. These involve numerous cell types and extracellular matrix molecules regulated by the actin cytoskeleton. This microscopic network of filaments is present within the cytoplasm of all cells and provides the shape and mechanical support required for cell movement and proliferation.
View Article and Find Full Text PDFCutaneous squamous cell carcinoma (cSCC) accounts for 25% of cutaneous malignancies diagnosed in Caucasian populations. Surgical removal in combination with radiation and chemotherapy are effective treatments for cSCC. Nevertheless, the aggressive metastatic forms of cSCC still have a relatively poor patient outcome.
View Article and Find Full Text PDFSilver-based nano-antibiotics are rapidly developing as promising alternatives to conventional antibiotics. Ideally, to remain potent against a wide range of drug-resistant and anaerobic bacteria, silver-based nano-antibiotics should easily penetrate through the bacterial cell walls and actively release silver ions. In this study, highly monodispersed, ultrasmall (<3 nm), polycationic silver nanoclusters (pAgNCs) are designed and synthesized for the elimination of a range of common Gram-negative and Gram-positive pathogens and their corresponding established and matured biofilms, including those composed of multiple species.
View Article and Find Full Text PDFSkin is an important barrier to pathogenic microorganisms and plays a critical role in a ctivation of innate immune responses. When the skin barrier is breached following wounding or burn injury, pathogens can invade and complicate healing with infection resulting in delayed healing and symptomatic scarring. Wound infection is a significant problem after burn injury and in patients with chronic wounds.
View Article and Find Full Text PDFBiofilm-associated infections are a major cause of impaired wound healing. Despite the broad spectrum of anti-bacterial benefits provided by silver nanoparticles (AgNPs), these materials still cause controversy due to cytotoxicity and a lack of efficacy against mature biofilms. Herein, highly potent ultrasmall AgNPs were combined with a biocompatible hydrogel with integrated synergistic functionalities to facilitate elimination of clinically relevant mature biofilms in-vivo combined with improved wound healing capacity.
View Article and Find Full Text PDFEpidermal progenitor cells divide symmetrically and asymmetrically to form stratified epidermis and hair follicles during late embryonic development. Flightless I (Flii), an actin remodelling protein, is implicated in Wnt/β-cat and integrin signalling pathways that govern cell division. This study investigated the effect of altering Flii on the divisional orientation of epidermal progenitor cells (EpSCs) in the basal layer during late murine embryonic development and early adolescence.
View Article and Find Full Text PDFPericytes have the potential to be developed as a cell therapy for the treatment of wounds; however, the efficacy of any cell therapy relies on the successful delivery of intact and functioning cells. Here, the effect of delivering pericytes on wound repair was assessed alongside the development of a surface-functionalized pericyte patch. Plasma polymerization (PP) was used to functionalize the surface of silicone patches with heptylamine (HA) or acrylic acid (AA) monomers.
View Article and Find Full Text PDFThe increasing emergence of antibiotic resistance coupled with the limited effectiveness of current treatments highlights the need for the development of new treatment modalities. Silver nanoparticles (AgNPs) are a promising alternative with broad-spectrum antibacterial activity. However, the clinical translation of AgNPs have been hampered primarily due to the delivery of unsafe levels of silver ions (Ag) resulting in cellular toxicity and their susceptibility to aggregation resulting in loss of efficacy.
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