Search Results (9)

The complexity of adverse responses from radiation injury (RI) followed by physical trauma, namely, radiation combined injury (RCI), is unique and more pronounced than either insult alone due to a poor understanding of the integration of these insults at the molecular/cellular/tissue and/or organ levels. It was shown that mice receiving ⁶⁰Co γ-photon RCI with wounding had a lower LD_50/30 than RI alone. This survival synergism was observed in bone marrow and the gastrointestinal system, as evidenced by an increase in γ-H2AX expression in bone marrow cell DNA, loss of circulatory blood cells, elevation of serum cytokine concentration, and activation of nuclear factor-κB/inducible nitric oxide synthase, and an earlier onset of bacterial infection and sepsis after RCI than after RI was detected. Dysbiosis (imbalance of the gut microbiota) was observed. There remains a pressing need for both prophylactic countermeasures and therapeutic remedies to deal with RCI threats. Investigations of how RCI can affect this important network of communication between the gut microbiota and other organs, including the brain, lung, heart, liver, kidney, and skin, could lead to new and critical interventions and prevention strategies. This review provides an update on new RCI animal models, dynamic changes in cytokine expression, dysbiosis, as well as links between the gut microbiome and other organs after RCI. Full article

Radiation therapy, a highly effective cancer treatment that targets cancer cells, may produce challenging side effects, including radiation-induced skin tissue injuries. The wound healing process involves complex cellular responses, with key phases including hemostasis, inflammation, proliferation, and remodeling. However, radiation-induced injuries disrupt this process, resulting in delayed healing, excessive scarring, and compromised tissue integrity. This review explores innovative approaches related to wound healing in post-radiotherapy defects, focusing on the integration of adipose-derived stem cells (ADSCs) in protein/polysaccharide bioengineered scaffolds. Such scaffolds, like hydrogels, sponges, or 3D-printed/bioprinted materials, provide a biocompatible and biomimetic environment that supports cell-to-cell and cell-to-matrix interactions. Various proteins and polysaccharides are discussed for beneficial properties and limitations, and their compatibility with ADSCs in wound healing applications. The potential of ADSCs-polymeric scaffold combinations in radiation-induced wound healing is investigated, alongside the mechanisms of cell proliferation, inflammation reduction, angiogenesis promotion, collagen formation, integrin binding, growth factor signaling, and activation of signaling pathways. New strategies to improve the therapeutic efficacy of ADSCs by integration in adaptive polymeric materials and designed scaffolds are highlighted, providing solutions for radiation-induced wounded skin, personalized care, faster tissue regeneration, and, ultimately, enhanced quality of the patients’ lives. Full article

Background/Objectives: Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis characterized by rapidly developing, painful ulcerative lesions. It exhibits pathergy, a phenomenon in which minor trauma or injury to the skin triggers an exaggerated inflammatory response. This leads to the development of new skin lesions or the worsening of existing ones. Treatment typically involves a combination of corticosteroids and immunosuppressive agents. However, even with effective therapy, the overall management of pyoderma gangrenosum remains challenging, and wound healing can be prolonged. The development of pyoderma gangrenosum after breast cancer surgery is rare, and its presence complicates the treatment of patients requiring additional oncologic therapy. In particular, the effect of radiation on these lesions is not well documented. Given the known skin toxicity of radiotherapy and its negative impact on wound healing, the use of adjuvant breast radiation raises significant concerns in this context. Methods: We present the case of a 66-year-old female with Stage IIB invasive ductal carcinoma of the left breast who developed postoperative pyoderma gangrenosum after breast-conserving surgery. The patient was treated with systemic corticosteroids and cyclosporine, and then subsequently underwent standard-of-care adjuvant chemotherapy and radiation. Results: During therapy, she demonstrated rapid resolution of her pyoderma gangrenosum without experiencing excess skin toxicity. Conclusions: While the literature on the direct application of radiation in pyoderma gangrenosum is limited, our case provides evidence supporting the safety of radiation therapy in oncologic cases complicated by this disease. In addition to receiving the benefit of adjuvant therapy for her breast cancer, our patient demonstrated an improvement in her postoperative PG with no adverse skin effects. Full article

Background/Objectives: Pre-operative radiation (Pre-RT) decreases local recurrence following soft tissue sarcoma (STS) resection but carries the risk of wound healing complications (WHCs). This study evaluated skin specimens and clinical characteristics of STS patients to (1) compare patients with and without Pre-RT, (2) compare Pre-RT patients with and without WHCs, and (3) explore associations between clinical characteristics and WHCs. Methods: This retrospective study included 54 adults who underwent STS resection with primary closure (Pre-RT n = 30). A pathologist who was blinded to the clinical outcomes evaluated the skin specimens microscopically. Results: Irradiated skin had lower vessel density and was more likely to lack hair follicles and sebaceous glands, consistent with the effects of radiation. Irradiated skin was also more likely to include plasma cells. Irradiated skin demonstrated higher mean TAZ H-scores; however, within the Pre-RT subset, those patients who developed WHCs demonstrated comparatively lower TAZ. Conclusions: This novel finding may suggest that higher TAZ in irradiated skin reflects a response to injury but that comparatively lower TAZ in irradiated skin might contribute to WHCs. Future studies should consider more focused evaluation of TAZ in STS resections with Pre-RT as they may help to predict WHCs when used in combination with other histologic factors and could suggest a therapeutic target. Full article

Currently, there are no U.S. Food and Drug Administration (FDA)-approved medical countermeasures (MCMs) for radiation combined injury (RCI), partially due to limited understanding of its mechanisms. Our previous research suggests that endothelial dysfunction may contribute to a poor prognosis of RCI. In this study, we demonstrated an increased risk of mortality, body weight loss, and delayed skin wound healing in RCI mice compared to mice with skin wounds alone or radiation injury (RI) 30 days post-insult. Furthermore, we evaluated biomarkers of endothelial dysfunction, inflammation, and impaired wound healing in mice at early time points after RCI. Mice were exposed to 9.0 Gy total-body irradiation (TBI) followed by skin wound. Samples were collected on days 3, 7, and 14 post-TBI. Endothelial dysfunction markers were measured by ELISA, and skin wound healing was assessed histologically. Our results show that endothelial damage and inflammation are more severe and persistent in the RCI compared to the wound-alone group. Additionally, RCI impairs granulation tissue formation, reduces myofibroblast presence, and delays collagen deposition, correlating with more severe endothelial damage. TGF signaling may play a key role in this impaired healing. These findings suggest that targeting the endothelial dysfunction and TGF-β pathways may provide potential therapeutic strategies for improving delayed wound healing in RCI, which could subsequently influence outcomes such as survival after RCI. Full article

Radiation injury- and radiation combined with skin injury-induced inflammatory responses in the mouse brain were evaluated in this study. Female B6D2F1/J mice were subjected to a sham, a skin wound (SW), 9.5 Gy ⁶⁰Co total-body gamma irradiation (RI), or 9.5 Gy RI combined with a skin puncture wound (RCI). Survival, body weight, and wound healing were tracked for 30 days, and mouse brain samples were collected on day 30 after SW, RI, RCI, and the sham control. Our results showed that RCI caused more severe animal death and body weight loss compared with RI, and skin wound healing was significantly delayed by RCI compared to SW. RCI and RI increased the chemokines Eotaxin, IP-10, MIG, 6Ckine/Exodus2, MCP-5, and TIMP-1 in the brain compared to SW and the sham control mice, and the Western blot results showed that IP-10 and p21 were significantly upregulated in brain cells post-RI or -RCI. RI and RCI activated both astrocytes and endothelial cells in the mouse brain, subsequently inducing blood–brain barrier (BBB) leakage, as shown by the increased ICAM1 and GFAP proteins in the brain and GFAP in the serum. The Doublecortin (DCX) protein, the “gold standard” for measuring neurogenesis, was significantly downregulated by RI and RCI compared with the sham group. Furthermore, RI and RCI decreased the expression of the neural stem cell marker E-cadherin, the intermediate progenitor marker MASH1, the immature neuron cell marker NeuroD1, and the mature neuron cell marker NeuN, indicating neural cell damage in all development stages after RI and RCI. Immunohistochemistry (IHC) staining further confirmed the significant loss of neural cells in RCI. Our data demonstrated that RI and RCI induced brain injury through inflammatory pathways, and RCI exacerbated neural cell damage more than RI. Full article

Radiation-combined injury (RCI) augments the risk of morbidity and mortality when compared to radiation injury (RI) alone. No FDA-approved medical countermeasures (MCMs) are available for treating RCI. Previous studies implied that RI and RCI elicit differential mechanisms leading to their detrimental effects. We hypothesize that accelerating wound healing improves the survival of RCI mice. In the current study, we examined the effects of RCI at different doses on lethality, weight loss, wound closure delay, and proinflammatory status, and assessed the relative contribution of systemic and local elements to their delayed wound closure. Our data demonstrated that RCI increased the lethality and weight loss, delayed skin wound closure, and induced a systemic proinflammatory status in a radiation dose-dependent manner. We also demonstrated that delayed wound closure did not specifically depend on the extent of hematopoietic suppression, but was significantly influenced by the toxicity of the radiation-induced systemic inflammation and local elements, including the altered levels of proinflammatory chemokines and factors, and the dysregulated collagen homeostasis in the wounded area. In conclusion, the results from our study indicate a close association between delayed wound healing and the significantly altered pathways in RCI mice. This insightful information may contribute to the evaluation of the prognosis of RCI and development of MCMs for RCI. Full article

Wound healing is seriously retarded when combined with ionizing radiation injury, because radiation-induced excessive reactive oxygen species (ROS) profoundly affect cell growth and wound healing. Mitochondria play vital roles not only as cellular energy factories but also as the main source of endogenous ROS, and in this work a mitochondria-targeting radioprotectant (CY-TMP1) is reported for radiation injury-combined wound repair. It was designed, synthesized and screened out from different conjugates between mitochondria-targeting heptamethine cyanine dyes and a peroxidation inhibitor 2,2,6,6-tetramethylpiperidinyloxy (TEMPO). CY-TMP1 specifically accumulated in mitochondria, efficiently mitigated mitochondrial ROS and total intracellular ROS induced by 6 Gy of X-ray ionizing irradiation, thereby exhibiting a notable radioprotective effect. The mechanism study further demonstrated that CY-TMP1 protected mitochondria from radiation-induced injury, including maintaining mitochondrial membrane potential (MMP) and ATP generation, thereby reducing the ratio of cell apoptotic death. Particularly, an in vivo experiment showed that CY-TMP1 could effectively accelerate wound closure of mice after 6 Gy of whole-body ionizing radiation. Immunohistochemical staining further indicated that CY-TMP1 may improve wound repair through angiogenesis and re-epithelialization. Therefore, mitochondria-targeting ROS scavengers may present a feasible strategy to conquer refractory wound combined with radiation injury. Full article

The goal of this study is to understand and mitigate the effects of wounds on acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), for preparedness against a radiological attack or accident. Combined injuries from concomitant trauma and radiation are likely in these scenarios. Either exacerbation or mitigation of radiation damage by wound trauma has been previously reported in preclinical studies. Female WAG/RijCmcr rats received 13 Gy X-rays, with partial-body shielding of one leg. Within 2 h, irradiated rats and non-irradiated controls were given full-thickness skin wounds with or without lisinopril, started orally 7 days after irradiation. Morbidity, skin wound area, breathing interval and blood urea nitrogen were measured up to 160 days post-irradiation to independently evaluate wound trauma and DEARE. Wounding exacerbated morbidity in irradiated rats between 5 and 14 days post-irradiation (during the ARS phase), and irradiation delayed wound healing. Wounding did not alter delayed morbidities from radiation pneumonitis or nephropathy after 30 days post-irradiation. Lisinopril did not mitigate wound healing, but markedly decreased morbidity during DEARE from 31 through 160 days. The results derived from this unique model of combined injuries suggest different molecular mechanisms of injury and healing of ARS and DEARE after radiation exposure. Full article