Human adipose ECM alleviates radiation-induced skin fibrosis via endothelial cell-mediated M2 macrophage polarization

P2Y6 promoted pruning of FSTL1 nerves by cutaneous macrophages to reset pain threshold and cardiac function

Hyperactivation of cutaneous macrophages promotes the development of chronic pain. Stimulation of nociceptive regions promotes neuroplasticity, which affects pain perception and related physiological responses. However, the specific mechanisms by which cutaneous macrophages sense and elicit nociceptive responses are unknown. Here, we exacerbated the reduction of systemic pain threshold after chronic heart failure (CHF) by silencing follistatin-like 1 (FSTL1), especially the abnormal cutaneous nociceptive sensation at PC6 acupoint, the site associated with cardiac involvement pain. The upregulation of P2Y6 and interleukin-27 expression is intimately linked to the activation of skin macrophages. Hyperactivation of P2Y6 receptor (P2Y6R) may be associated with MHC II M1+ macrophage polarization in PC6. Thus, P2Y6 is one of the key factors that modulate the functional polarization of skin macrophages, which may subsequently influence the expansion of the pain field. The supportive effect of CD206 M2+ macrophages on the cutaneous FSTL1+ nerves was significantly reduced. Meanwhile, FSTL1+ nerves in PC6 functionally interacted with calcitonin gene-related peptide (CGRP)+ nerves, and the overactivation of nerve growth factor (NGF) secreted by cutaneous macrophages induced CGRP+ neuropathological remodeling, which supported the enlargement of the pain sensory area. The activation of CGRP and P2X3 receptor (P2X3R), Na+/K+ ATPase (NKA), and P2X3R in the C8 DRG may be one of the molecular bases mediating cutaneous nociceptive transmission and affecting the function of the heart. Hyperactivation of NKA was consistent with decreased pain threshold and changes in cardiac dysfunction, and PC6 injection of an NKA inhibitor (digilanid C) was effective in ameliorating nociception and cardiac impairment. The beneficial effects of digilanid C were counteracted by FSTL1 silencing. These results indicated that P2Y6 mediates the remodeling of pain perception by skin macrophages via the action of FSTL1, while NKA inhibitors synergistically exert their therapeutic effects.

Fat Grafting and Prepectoral Prosthetic Reconstruction with Polyurethane-Covered Implants: Protective Role against Adjuvant Radiotherapy

Background/Objectives: Breast cancer treatment increasingly incorporates immediate prepectoral prosthetic reconstruction after conservative mastectomy, including nipple-sparing (NSMs) and skin-sparing mastectomies (SSMs). Although recent data from the literature show that postmastectomy radiotherapy (PMRT) after prepectoral reconstruction presents good clinical results, with reduction in capsular contracture and implant migration, compared to the traditional submuscular technique, these patients have higher rates of long-term complications when compared with nonradiated patients. This study evaluates the protective effects of autologous fat grafting to reduce long-term radiotherapy-induced complications in breast cancer patients submitted for prepectoral reconstruction with polyurethane-covered (PU) implants. Methods: A pilot study with two parallel cohorts of patients undergoing an NSM or SSM followed by PMRT was conducted. Patients were randomly assigned to either of the two groups to ensure homogeneity. One cohort underwent autologous fat grafting sessions, individually tailored based on periodic evaluations by the principal investigator (PI), M. Salgarello, at least six months after PMRT. The control group received standard clinical follow-ups without fat grafting. Inclusion criteria ensured participants were disease-free, non-smokers, and had a LENT-SOMA score within 2. Results: Preliminary findings indicate significant differences between the groups, with improved outcomes observed in patients undergoing tailored lipofilling. Specifically, these patients experienced a notable reduction in capsular contracture severity and reported higher satisfaction with the aesthetic results compared to the control group. Conclusions: Autologous fat grafting, customized per patient by the PI based on ongoing evaluations, appears to mitigate some adverse effects of radiotherapy in prepectoral breast reconstruction, suggesting a viable option for enhancing surgical outcomes in irradiated patients. Further research is needed to substantiate these findings and evaluate long-term benefits.

Multifunctional Glycopeptide-Based Hydrogel via Dual-Modulation for the Prevention and Repair of Radiation-Induced Skin Injury

The radiation-induced skin injury (RISI) remains a great challenge for clinical wound management and care after radiotherapy, as patients will suffer from the acute radiation injury and long-term chronic inflammatory damage during the treatment. The excessive ROS in the early acute stage and prolonged inflammatory response in the late healing process always hinder therapeutic efficiency. Herein, we developed an extracellular matrix (ECM)-mimetic multifunctional glycopeptide hydrogel (oCP@As) to promote and accelerate RISI repair via a dual-modulation strategy in different healing stages. The oCP@As hydrogel not only can form an ECM-like nanofiber structure through the Schiff base reaction but also exhibits ROS scavenging and DNA double-strand break repair abilities, which can effectively reduce the acute radiation damage. Meanwhile, the introduction of oxidized chondroitin sulfate, which is the ECM polysaccharide-like component, enables regulation of the inflammatory response by adsorption of inflammatory factors, accelerating the repair of chronic inflammatory injury. The animal experiments demonstrated that oCP@As can significantly weaken RISI symptoms, promote epidermal tissue regeneration and angiogenesis, and reduce pro-inflammatory cytokine expression. Therefore, this multifunctional glycopeptide hydrogel dressing can effectively attenuate RISI symptoms and promote RISI healing, showing great potential for clinical applications in radiotherapy protection and repair.

Biomaterials-mediated radiation-induced diseases treatment and radiation protection

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field.

Exploring Anti-Fibrotic Effects of Adipose-Derived Stem Cells: Transcriptome Analysis upon Fibrotic, Inflammatory, and Hypoxic Conditioning

Autologous fat transfers show promise in treating fibrotic skin diseases, reversing scarring and stiffness, and improving quality of life. Adipose-derived stem cells (ADSCs) within these grafts are believed to be crucial for this effect, particularly their secreted factors, though the specific mechanisms remain unclear. This study investigates transcriptomic changes in ADSCs after in vitro fibrotic, inflammatory, and hypoxic conditioning. High-throughput gene expression assays were conducted on ADSCs exposed to IL1-β, TGF-β1, and hypoxia and in media with fetal bovine serum (FBS). Flow cytometry characterized the ADSCs. RNA-Seq analysis revealed distinct gene expression patterns between the conditions. FBS upregulated pathways were related to the cell cycle, replication, wound healing, and ossification. IL1-β induced immunomodulatory pathways, including granulocyte chemotaxis and cytokine production. TGF-β1 treatment upregulated wound healing and muscle tissue development pathways. Hypoxia led to the downregulation of mitochondria and cellular activity.

Metformin and adipose-derived stem cell combination therapy alleviates radiation-induced skin fibrosis in mice

BACKGROUND

Radiation therapy often leads to late radiation-induced skin fibrosis (RISF), causing movement impairment and discomfort. We conducted a comprehensive study to assess the effectiveness of metformin and adipose-derived stem cells (ASCs), whether autologous or allogeneic, individually or in combination therapy, in mitigating RISF.

METHODS

Using a female C57BL/6J mouse model subjected to hind limb irradiation as a representative RISF model, we evaluated metformin, ASCs, or their combination in two contexts: prophylactic (started on day 1 post-irradiation) and therapeutic (initiated on day 14 post-irradiation, coinciding with fibrosis symptoms). We measured limb movement, examined skin histology, and analyzed gene expression to assess treatment efficacy.

RESULTS

Prophylactic metformin and ASCs, whether autologous or allogeneic, effectively prevented late fibrosis, with metformin showing promising results. However, combination therapy did not provide additional benefits when used prophylactically. Autologous ASCs, alone or with metformin, proved most effective against late-stage RISF. Prophylactic intervention outperformed late therapy for mitigating radiation skin damage. Co-culture studies revealed that ASCs and metformin downregulated inflammation and fibrotic gene expression in both mouse and human fibroblasts.

CONCLUSIONS

Our study suggests metformin's potential as a prophylactic measure to prevent RISF, and the combination of ASCs and metformin holds promise for late-stage RISF treatment. These findings have clinical implications for improving the quality of life for those affected by radiation-induced skin fibrosis.