Wound Repair and Regeneration最新文献

We tested if hyperoxic conditions can reduce the proportion of active myofibroblasts, which are assumed to be a major driver of head and neck radiation-induced fibrosis, as measured by expression levels of pro-fibrotic genes. Radiated, non-cancerous soft tissue from the head and neck and skin/soft tissue from non-radiated flap donor site were collected from each patient. Myofibroblast density was quantified using immunofluorescence staining with α-SMA and DAPI and visualisation under confocal microscopy and compared between baseline non-radiated and radiated tissue from the same patient. From each tissue specimen, fibroblast cell lines were cultured and exposed to either normoxic, hypoxic, or hyperoxic conditions for 10 days. Total RNA was extracted and reverse-transcribed, and gene expression levels were quantified using RT-PCR. Relative gene expression levels of pro-fibrotic genes COL1A1, COL3A1, FN-EDA, α-SMA, HIF-1α, VEGFα, and VEGFR were compared between normoxic, hypoxic, and hyperoxic treatment groups. Three patients with six total tissue samples were acquired. Radiated tissue contained a higher density of myofibroblasts (calculated as cells/mm²) and demonstrated higher expression of pro-fibrotic genes than non-radiated donor site tissue. Hyperoxia decreases expression levels of pro-fibrotic genes in radiated and non-radiated tissue, while hypoxia increases pro-fibrotic gene expression levels in radiated and non-radiated tissue. Study findings indicate that hypoxia is a driver of myofibroblast activation and that subjects with radiation-induced fibrosis of the head and neck have increased expression of myofibroblastic phenotype. Hyperoxygenation can reduce the proportion of active myofibroblasts, revealing a potential therapeutic method to halt chronic fibrotic pathways.

Intralesional 5-fluorouracil (5-FU) injections are effective for treating keloid scars but are often associated with pain, hyperpigmentation and ulceration, limiting patient compliance. Dissolving microneedle (DMN) patches offer a novel, minimally invasive and potentially painless alternative for drug delivery. This study aimed to compare the efficacy and safety of 5-FU DMN patches with intralesional 5-FU injections for the treatment of keloid scars. A total of 37 patients were enrolled in this randomised, single-blind clinical trial. Each scar was split in half, with one half treated weekly using 5-FU DMN patches for 12 weeks and the other half receiving monthly intralesional 5-FU injections over the same period. Outcomes were assessed using the Patient and Observer Scar Assessment Scale (POSAS) and scar volume measurements via multispectral imaging at baseline and Weeks 4, 8, 12 and 24. Both treatments significantly improved POSAS scores and reduced keloid volume over time. Intralesional injections resulted in a faster response and significantly greater volume reduction at Week 12 (p = 0.008), but by Week 24, no significant difference in efficacy was observed between the two methods. DMN patches were associated with significantly less pain and better patient comfort. These findings support the use of 5-FU DMN patches as a minimally invasive, patient-friendly alternative to injections for the long-term management of keloid scars.

Histologic analyses of burn tissue are unable to discern reversible injury. Advanced molecular profiling, such as bulk RNA-sequencing, provides more detail; however, these methods lose spatial context. Spatial transcriptomics allows gene transcripts to be mapped to tissue locations, revealing the molecular pathways activated in the burn tissue microenvironment, where the depth of injury guides prognosis. This work demonstrates the capability of spatial transcriptomics to detect spatial gene expression patterns in burn tissue. Specifically, we show that (i) spatially variable expressed genes are distinct across different burn depth regions, which would not be identified with bulk RNA-sequencing, (ii) transcriptionally distinct burn tissue regions are defined by gene signatures associated with diverse cell types and biological pathways, and (iii) these spatial gene signatures are identified in a subset of previously published bulk samples, suggesting their potential application in large-scale and integrated studies. Caveats of this technology in burn tissue are provided to guide future research. This study highlights the promise of spatial transcriptomics to understand the human burn wound microenvironment and identify specific regions with regenerative potential that can be the target of tailored therapeutics, providing an alternative to imprecise excision and skin grafting.

Macrophages play a critical role in wound healing. Modulating macrophage activity has thus been identified as a potential strategy to stimulate immune-mediated tissue regeneration. This study utilised endotoxin tolerization as a strategy to dampen cytokine production upon the ex vivo activation of M2 monocytic cells before collecting their secretome for therapeutic application. The M2 derived secretome was harvested from GM-CSF differentiated THP-1 cells followed by IL4-induced M2 polarisation with or without prior endotoxin tolerization. The protein constituents of the secretome were determined and quantified using label free LC-MS/MS analysis and cytokine levels using enzyme-linked immunosorbent assays. The efficacy of the M2 derived secretome (with and without prior tolerization) to stimulate fibroblast activity was assessed in vitro (scratch assay) and in vivo (murine full thickness wound model). In culture, the secretome (regardless of tolerization) stimulated fibroblast migration and increased the release of hydroxyproline, which is an essential requirement for collagen synthesis. Similarly, in full thickness excisional wounds, a single application of the M2 monocytic cell secretory products post wounding significantly increased collagen deposition within the wounded area compared to controls. There was however no difference evident in the healing outcomes between the wounds treated with M2 monocytic cell derived secretome without tolerization and those treated with secretome derived from tolerized M2 monocytic cells. Despite its impact on ECM deposition in the wound bed, the secretome showed no benefit for superficial wound closure and did not improve the overall histology score. Taken together, the data suggest that M2 secretory products pose a risk for excessive scar formation.

Chronic wounds are a major healthcare problem, consuming resources globally and necessitating innovative wound dressing development. All antimicrobial wound dressings must be tested for safety and antibacterial effectiveness prior to patient use. This study aimed to develop a rapid, economical in vitro assay and biorelevant ex vivo wound biofilm model on porcine skin to test the antibacterial efficacy of antimicrobial wound dressings. The methods were validated using five commercially available wound dressings and experimental electrospun (ES) wound dressing containing chloramphenicol in polycaprolactone and polyethylene oxide fibres (PCL/PEO/CAM). An in vitro assay was used to assess the growth inhibition, killing efficacy, and dressing sterility against multiple bacterial strains and inoculum sizes. Ex vivo models using porcine skin were used to evaluate biofilm inhibition with dressings on top of or inside infected wounds. The in vitro assay allowed rapid initial screening, whilst ex vivo models provided more biorelevant conditions for understanding the efficacy in wound-mimicking environments. The assay and model are suitable for rapid evaluation of antimicrobial efficacy before animal studies and clinical trials. Using various commercially available wound dressings alongside novel dressings for validation ensures that the method is broadly applicable. The antibacterial efficacy of commercial antimicrobial wound dressings and experimental ES PCL/PEO/CAM fibre mat was confirmed. This study highlights the importance of using multiple complementary assays and models to comprehensively assess antimicrobial wound dressing materials.

Rotator cuff (RC) pathology encompasses a wide range of conditions, which include bursitis, tendinitis, tendinosis, partial thickness tears and full-thickness tears. To treat painful musculoskeletal problems, low-level laser therapy (LLLT) has been employed as a non-pharmacological alternative. Photobiomodulation (PBM), which uses light-emitting diodes (LEDs) and other photo-emitting devices, is a minimally invasive approach used to treat a wide range of conditions. The purpose of this pre-post study design is to evaluate the effectiveness of PBM and exercise-based rehabilitation on pain and functional recovery in patients with RC pathology. Twenty of the thirty-seven patients who were tested for shoulder disorders and found to have RC pathology were included in the study. The patients' pain levels were measured using the Numerical Pain Rating Scale (NPRS) both at baseline and 6 weeks later. The mean ± standard deviation of NPRS was calculated, data was checked for normal distribution, and the Wilcoxon rank test was conducted to compare the values. Our study showed a statistically significant reduction in pain scores from baseline (7.33 ± 0.79) to 6 weeks (2.50 ± 0.69), p < 0.001 of PBM and exercise-based rehabilitation. The knowledge about the evidence regarding the effectiveness of PBM, along with exercise-based rehabilitation, is critical.

Delayed wound healing and non-healing wounds are common in diabetic patients due to the hostile microenvironments and complex pathophysiology of diabetic wounds. Addressing these challenges remains a significant concern for clinicians and researchers. Recently, microneedle technology has emerged as an effective, minimally invasive delivery system for treating diabetic wounds, offering ease of use and efficient drug delivery. Naturally derived biomaterial-based microneedles have demonstrated excellent biocompatibility, degradability, and low toxicity, enhancing the healing process by providing mechanical support and delivering antimicrobial agents, growth factors, and antioxidants. Some microneedles are designed to adapt to the specific microenvironments of diabetic wounds, leading to improved healing outcomes. This review summarises the design and development of naturally derived biomaterial-based microneedles for diabetic wound healing and discusses the mechanisms of action in response to varying diabetic wound conditions. The review also addresses critical considerations for developing microenvironment-response microneedles, highlighting implications for translational medicine. Collectively, interdisciplinary collaboration and technological innovation have advanced the creation of these microenvironment-response microneedles using natural biomaterials, which hold significant potential for improving diabetic wound healing.

The late 1980s saw the emergence of experimental therapies based on human cell and tissue products (HCTPs) within academic and hospital settings, several of them wound healing related. In 2008, the European Commission introduced the Regulation on advanced therapy medicinal products (ATMPs), defining many of these HCTPs as ATMPs, and more specifically as somatic cell therapy medicinal products (sCTMPs) or tissue-engineered products (TEPs). In 2013, we predicted that the ATMP regulation would adversely impact Member States' health care systems and would threaten the sustainability of many HCTPs provided by public health institutions. To assess the current ATMP state of play and investigate whether these predictions ultimately came true, we consulted relevant scientific and trade literature and official competent authority reports and surveyed the former Belgian HCTP producers. We found that the ATMP Regulation produced 19 authorised ATMPs, with 16 of them (84.2%) belonging to the gene therapy medicinal product (GTMP) class and only 3 HCTPs (15.8%), 2 TEPs and 1 sCTMP. List prices varied according to the ATMP class, with public health insurances struggling to reimburse ATMPs, especially the exuberantly priced GTMPs. This led to marketing authorization withdrawals, and crowd funding approaches and lotteries to determine who would receive lifesaving treatments. A hospital exemption (HE) scheme was enacted to protect ATMPs not intended for commercial exploitation. Whilst limited financial resources generally hampered HE utilisation by public actors, stringent regulatory policies made it virtually impossible in Belgium, resulting in meaningful HCTPs no longer being available to surgeons and their patients.