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Endogenous glucocorticoids and commonly used oral glucocorticoids have the property of existing in an inactive and active form in vivo. The inactive form can be converted back to the active form, or ‘recycled’ in cells and tissues that express the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme. This recycling provides an important contribution to the action of glucocorticoids. This review examines the literature relating to the importance of 11β-HSD1 activity during glucocorticoid treatment, with an emphasis on studies examining bone and joint disease and the ability of glucocorticoids to suppress inflammatory damage in models of arthritis. Animal models with global or selective deletion of 11β-HSD1 have determined the extent to which this recycling is important in normal physiology and during treatment with oral glucocorticoids. These studies demonstrate that 11β-HSD1-mediated recycling of inactive glucocorticoids has a substantial action and indeed is responsible for the majority of the effects of orally administered glucocorticoids on a range of tissues. Importantly, the anti-inflammatory actions of glucocorticoids appear largely through this mechanism such that mice that lack 11β-HSD1 are resistant to the anti-inflammatory actions of glucocorticoids. The recognition that to a large extent the circulating inactive counterpart of these glucocorticoids is more important to anti-inflammatory effects than the active glucocorticoid presents novel opportunities to more selectively target glucocorticoids to tissues or to reduce the likely side effects. [ABSTRACT FROM AUTHOR]

Wound healing is a complex process involving multiple independent and overlapping sequential physiological mechanisms. In addition to cutaneous injury, a severe burn stimulates physiological derangements that induce a systemic hypermetabolic response resulting in impaired wound healing. Topical application of the anti-androgen drug, flutamide accelerates cutaneous wound healing, whereas paradoxically systemic dihydrotestosterone (DHT) improves burn wound healing. We developed and characterized a PCL scaffold that is capable of controlled release of androgen (DHT) and anti-androgen (F) individually or together. This study aims to investigate whether local modification of androgen actions has an impact on burn injury wound healing. In a full-thickness burn wound healing, mouse model, DHT/F-scaffold showed a significantly faster wound healing compared with F-scaffold or DHT-scaffold. Histology analysis confirmed that DHT/Fscaffold exhibited higher re-epithelization, cell proliferation, angiogenesis, and collagen deposition. Dual release of DHT and F from PCL scaffolds promoted cell proliferation of human keratinocytes and alters the keratinocyte cell cycle. Lastly, no adverse effects on androgen-dependent organs, spleen and liver were observed. In conclusion, we demonstrated DHT plus F load PCL scaffolds accelerated burn wound healing when loading alone did not. These findings point to a complex role of androgens in burn wound healing and open novel therapeutic avenues for treating severe burn patients. [ABSTRACT FROM AUTHOR]

Wound healing is a complex process involving multiple independent and overlapping sequential physiological mechanisms. In addition to cutaneous injury, a severe burn stimulates physiological derangements that induce a systemic hypermetabolic response resulting in impaired wound healing. Topical application of the anti‐androgen drug, flutamide accelerates cutaneous wound healing, whereas paradoxically systemic dihydrotestosterone (DHT) improves burn wound healing. We developed and characterized a PCL scaffold that is capable of controlled release of androgen (DHT) and anti‐androgen (F) individually or together. This study aims to investigate whether local modification of androgen actions has an impact on burn injury wound healing. In a full‐thickness burn wound healing, mouse model, DHT/F‐scaffold showed a significantly faster wound healing compared with F‐scaffold or DHT‐scaffold. Histology analysis confirmed that DHT/F‐scaffold exhibited higher re‐epithelization, cell proliferation, angiogenesis, and collagen deposition. Dual release of DHT and F from PCL scaffolds promoted cell proliferation of human keratinocytes and alters the keratinocyte cell cycle. Lastly, no adverse effects on androgen‐dependent organs, spleen and liver were observed. In conclusion, we demonstrated DHT plus F load PCL scaffolds accelerated burn wound healing when loading alone did not. These findings point to a complex role of androgens in burn wound healing and open novel therapeutic avenues for treating severe burn patients. [ABSTRACT FROM AUTHOR]

[Display omitted] Delayed wound healing is one of the most global public health threats affecting nearly 100 million people each year, particularly the chronic wounds. Many confounding factors such as aging, diabetic disease, medication, peripheral neuropathy, immunocompromises or arterial and venous insufficiency hyperglycaemia are considered to inhibit wound healing. Therapeutic approaches for slow wound healing include anti-infection, debridement and the use of various wound dressings. However, the current clinical outcomes are still unsatisfied. In this review, we discuss the role of skin and wound commensal microbiota in the different healing stages, including inflammation, cell proliferation, re-epithelialization and remodelling phase, followed by multiple immune cell responses to commensal microbiota. Current clinical management in treating surgical wounds and chronic wounds was also reviewed together with potential controlled delivery systems which may be utilized in the future for the topical administration of probiotics and microbiomes. This review aims to introduce advances, novel strategies, and pioneer ideas in regulating the wound microbiome and the design of controlled delivery systems. [ABSTRACT FROM AUTHOR]

Androgens have been known to inhibit cutaneous wound healing in men and male mice. However, in children with major burn injuries, a synthetic androgen was reported clinically to improve wound healing. The aim of this study is to investigate the role of dihydrotestosterone (DHT) as a new therapeutic approach in treating major burn injury. In the present study, mice received systemic androgen treatment post major burn injury. Wound healing rate and body weight were monitored over 21 days. The serum level of inflammatory cytokines/chemokines were measured using multiplex immunoassays. In addition, splenocyte enumeration was performed by flow cytometry. Healing phases of inflammation, re-epithelialization, cell proliferation and collagen deposition were also examined. In results, DHT treated mice lost less weight and displayed accelerated wound healing but has no impact on hypermetabolism. Mice, after burn injury, displayed acute systemic inflammatory responses over 21 days. DHT treatment shortened the systemic inflammatory response with reduced splenic weight and monocyte numbers on day 14 and 21. DHT treatment also reduced wound infiltrating macrophage numbers. In conclusion, DHT treatment facilitates local wound healing by accelerating the resolution of inflammation, but not through alterations of post-burn hypermetabolic response. [ABSTRACT FROM AUTHOR]