Abstract Injectable self-healing hydrogel dressing with multifunctional properties including anti-infection, anti-oxidative and conductivity promoting wound healing process will be highly desired in ...wound healing application and its design is still a challenge. We developed a series of injectable conductive self-healed hydrogels based on quaternized chitosan-g-polyaniline (QCSP) and benzaldehyde group functionalized poly(ethylene glycol)-co-poly(glycerol sebacate) (PEGS-FA) as antibacterial, anti-oxidant and electroactive dressing for cutaneous wound healing. These hydrogels presented good self-healing, electroactivity, free radical scavenging capacity, antibacterial activity, adhesiveness, conductivity, swelling ratio, and biocompatibility. Interestingly, the hydrogel with an optimal crosslinker concentration of 1.5 wt% PEGS-FA showed excellent in vivo blood clotting capacity, and it significantly enhanced in vivo wound healing process in a full-thickness skin defect model than quaternized chitosan/PEGS-FA hydrogel and commercial dressing (Tegaderm™ film) by upregulating the gene expression of growth factors including VEGF, EGF and TGF-β and then promoting granulation tissue thickness and collagen deposition. Taken together, the antibacterial electroactive injectable hydrogel dressing prolonged the lifespan of dressing relying on self-healing ability and significantly promoted the in vivo wound healing process attributed to its multifunctional properties, meaning that they are excellent candidates for full-thick skin wound healing.
Microporous annealed particle (MAP) scaffolds are flowable, in situ crosslinked, microporous scaffolds composed of microgel building blocks and were previously shown to accelerate wound healing. To ...promote more extensive tissue ingrowth before scaffold degradation, we aimed to slow MAP degradation by switching the chirality of the crosslinking peptides from L- to D-amino acids. Unexpectedly, despite showing the predicted slower enzymatic degradation in vitro, D-peptide crosslinked MAP hydrogel (D-MAP) hastened material degradation in vivo and imparted significant tissue regeneration to healed cutaneous wounds, including increased tensile strength and hair neogenesis. MAP scaffolds recruit IL-33 type 2 myeloid cells, which is amplified in the presence of D-peptides. Remarkably, D-MAP elicited significant antigen-specific immunity against the D-chiral peptides, and an intact adaptive immune system was required for the hydrogel-induced skin regeneration. These findings demonstrate that the generation of an adaptive immune response from a biomaterial is sufficient to induce cutaneous regenerative healing despite faster scaffold degradation.
The Immune Landscape of Cancer Bortone, Dante S.; Eddy, James A.; Liu, Yuexin ...
Immunity,
04/2018, Volume:
48, Issue:
4
Journal Article
Peer reviewed
Open access
We performed an extensive immunogenomic analysis of more than 10,000 tumors comprising 33 diverse cancer types by utilizing data compiled by TCGA. Across cancer types, we identified six immune ...subtypes—wound healing, IFN-γ dominant, inflammatory, lymphocyte depleted, immunologically quiet, and TGF-β dominant—characterized by differences in macrophage or lymphocyte signatures, Th1:Th2 cell ratio, extent of intratumoral heterogeneity, aneuploidy, extent of neoantigen load, overall cell proliferation, expression of immunomodulatory genes, and prognosis. Specific driver mutations correlated with lower (CTNNB1, NRAS, or IDH1) or higher (BRAF, TP53, or CASP8) leukocyte levels across all cancers. Multiple control modalities of the intracellular and extracellular networks (transcription, microRNAs, copy number, and epigenetic processes) were involved in tumor-immune cell interactions, both across and within immune subtypes. Our immunogenomics pipeline to characterize these heterogeneous tumors and the resulting data are intended to serve as a resource for future targeted studies to further advance the field.
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•Six identified immune subtypes span cancer tissue types and molecular subtypes•Immune subtypes differ by somatic aberrations, microenvironment, and survival•Multiple control modalities of molecular networks affect tumor-immune interactions•These analyses serve as a resource for exploring immunogenicity across cancer types
Thorsson et al. present immunogenomics analyses of more than 10,000 tumors, identifying six immune subtypes that encompass multiple cancer types and are hypothesized to define immune response patterns impacting prognosis. This work provides a resource for understanding tumor-immune interactions, with implications for identifying ways to advance research on immunotherapy.
Neutrophil migration and its role during inflammation has been the focus of increased interest in the past decade. Advances in live imaging and the use of new model systems have helped to uncover the ...behaviour of neutrophils in injured and infected tissues. Although neutrophils were considered to be short-lived effector cells that undergo apoptosis in damaged tissues, recent evidence suggests that neutrophil behaviour is more complex and, in some settings, neutrophils might leave sites of tissue injury and migrate back into the vasculature. The role of reverse migration and its contribution to resolution of inflammation remains unclear. In this Review, we discuss the different cues within tissues that mediate neutrophil forward and reverse migration in response to injury or infection and the implications of these mechanisms to human disease.
Skin wound healing is an intractable problem that represents an urgent clinical need. To solve this problem, a large number of studies have focused on the use of exosomes (EXOs) derived from ...adipose‐derived stem cells (ADSCs). This review describes the mechanisms whereby ADSCs‐EXOs regulate wound healing and their clinical application. In the wound, ADSCs‐EXOs modulate immune responses and inflammation. They also promote angiogenesis, accelerate proliferation and re‐epithelization of skin cells, and regulate collagen remodelling which inhibits scar hyperplasia. Compared with ADSCs therapeutics, ADSCs‐EXOs have highly stability and are easily stored. Additionally, they are not rejected by the immune system and have a homing effect and their dosage can be easily controlled. ADSCs‐EXOs can improve fat grafting and promote wound healing in patients with diabetes mellitus. They can also act as a carrier and combined scaffold for treatment, leading to scarless cutaneous repair. Overall, ADSCs‐EXOs have the potential to be used in the clinic to promote wound healing.
This review describes the mechanisms whereby exosomes (EXOs) derived from adipose‐derived stem cells (ADSCs) regulate wound healing and their clinical application. In the wound, ADSCs‐EXOs modulate immune responses and inflammation, promote angiogenesis, accelerate proliferation and re‐epithelization of skin cells and regulate collagen remodelling, which inhibits scar hyperplasia. ADSCs‐EXOs have the potential to be used in the clinic, as they can improve fat grafting, promote wound healing of diabetic patients and act as a carrier and combined scaffold for treatment, leading to scarless cutaneous repair.
Summary
A considerable understanding of the fundamental cellular and molecular mechanisms underpinning healthy acute wound healing has been gleaned from studying various animal models, and we are now ...unravelling the mechanisms that lead to chronic wounds and pathological healing including fibrosis. A small cut will normally heal in days through tight orchestration of cell migration and appropriate levels of inflammation, innervation and angiogenesis. Major surgeries may take several weeks to heal and leave behind a noticeable scar. At the extreme end, chronic wounds – defined as a barrier defect that has not healed in 3 months – have become a major therapeutic challenge throughout the Western world and will only increase as our populations advance in age, and with the increasing incidence of diabetes, obesity and vascular disorders. Here we describe the clinical problems and how, through better dialogue between basic researchers and clinicians, we may extend our current knowledge to enable the development of novel potential therapeutic treatments.
What's already known about this topic?
Much is known about the sequence of events contributing to normal healing.
The two pathologies of wound healing are chronic wounds and scarring.
What does this study add?
We explain how the cell and molecular mechanisms of healing guide the therapeutic strategies.
We introduce zebrafish and the fruit fly, Drosophila as novel wound healing models.
We highlight unanswered questions and future directions for wound healing research.
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