Search Results (2,257)

This paper proposes a method to analyze the effect of the rotor’s harmonic winding design and the output of a brushless wound rotor synchronous machine (WRSM) for optimal excitation power transfer. In particular, the machine analyzed by the finite-element method was a 48-slot eight-pole 2D model. The subharmonic magnetomotive force was additionally created in the air gap flux, which induces voltage in the harmonic winding of the rotor. This voltage is rectified and fed to the field winding through a full bridge rectifier. Eventually, a direct current (DC) flows to the field winding, removing the need for external excitation through brushes and sliprings. The effect of the number of harmonic winding turns is analyzed and the field winding turns were varied with respect to the available rotor slot space. Optimization of the harmonic excitation part of the machine will maximize the rotor excitation for regulation purposes and optimize the torque production at the same time. Two-dimensional finite-element analysis has been performed in ANSYS Maxwell 19 to obtain the basic results for the design of the machine. Full article

This study reports the use of an in situ-forming gel based on hyaluronic–chitosan–glycerophosphate for wound healing. Hydrogels with optimized thermoresponsive gelling, rheological, and prolonged drug release properties were developed and incorporated with ciprofloxacin and carvacrol. In vitro evaluations included rheological studies, swelling degree, degradation rates, morphological analysis, antioxidant effects, antimicrobial activity, and drug release studies. The effectiveness of the optimized hydrogel was assessed using an animal ischemic wound rabbit ear model. The incorporation of ciprofloxacin and carvacrol into the combined hydrogel system maintained the mechanical strength of the formula, with a G′/G″ ≈ ratio of approximately 15.6, interconnected porosity, and controlled swelling. It enhanced antimicrobial activity against both S. aureus and E. coli. In addition, the developed gel exhibited sustained release following the Higuchi diffusion kinetics. The quantitative wound area% indicated that on day 9, the mean wound area decreased from 81.8% for the control to 51.2% for the developed gel. The study findings demonstrate the suitability and potential of this system as multifunctional wound-healing formulations that promote moist healing, antimicrobial and antioxidant activities, while providing sustained therapeutic delivery over 24 h. Full article

Second-degree burns are common dermal injuries requiring effective interventions to promote timely and complete skin regeneration. This study evaluated the wound-healing efficacy of topical hydrogels containing powdered licorice root (Glycyrrhiza glabra L.) extract at concentrations of 5%, 10%, and 20% w/w in a standardized murine model. Female SKH-hrHR2 hairless mice (n = 8 per group) were subjected to second-degree thermal burns, and treatment hydrogel formulations were applied once daily under occlusive dressings. Wound healing was assessed by planimetric area measurements, transepidermal water loss (TEWL), and histopathology. By Day 19, complete wound closure was achieved in 87.5% of animals in the 5% group, compared with 50.0% in the 10% group, 37.5% in the 20% group, and 25.0% in the sodium alginate control (Fisher’s exact test, p = 0.008). TEWL remained unchanged in the 5% group (baseline vs. Day 19: 8.4 ± 1.2 vs. 8.6 ± 1.3 g/m²/h; p > 0.05) but increased significantly in all other groups (e.g., sodium alginate: 8.2 ± 1.1 to 13.5 ± 2.0 g/m²/h; p = 0.0001). Histologically, the 5% formulation showed near-normal epidermal architecture and minimal inflammation (mean total score 2.0) compared with higher concentrations (6.0 for 10% and 7.3 for 20%) and sodium alginate (8.3). These findings demonstrate that a 5% Glycyrrhiza glabra hydrogel provides, among the concentrations studied here, the most favorable balance of wound closure, barrier restoration, and histological recovery, supporting its further development as a topical therapy for second-degree burns. Full article

The use of saponins with biosurfactant, antioxidant, anti-inflammatory, and anti-cancer properties is limited by their toxicity and bioavailability. This study focused on the fabrication, characterization, and bioactivity of crude tea saponin (TS) and TS-incorporated silica nanoparticles (TSNPs). Our results showed that TS contained seven saponins and that TSNPs had an average diameter of 200–300 nm, a negative surface charge, and high polydispersity. Fourier Transform Infrared Spectroscopy (FTIR) revealed an incorporation bond of Si-O- and -OH controlling releasing behavior with t₅₀ = 24 h. Using HaCaT cells, it was demonstrated that TSNPs reduced cytotoxicity. Reactive oxygen species (ROS) production was lowered in both TS and TSNP treatments, with significantly greater efficacy at higher concentrations. Additionally, TSNPs significantly accelerated cell migration in the wound closure model as efficiently as TGFβ. Together, these findings offer promising TSNPs for biomedical applications and therapeutic agents due to their antioxidant properties, cytotoxicity protection, and wound closure acceleration. Full article

Despite advancement in skin engineering, native skin grafting remains the gold standard in clinical settings. We have previously demonstrated that a platelet-derived hydrogel (PG) can act as a scaffold to engineer a semi-mature bilaminar human skin equivalent (PG-HSE). In this study, PG-HSE was grafted on full thickness wounds in athymic mice. PG-HSE was compared with native skin autografts and a clinically proven bilaminar skin graft that utilises a single layer NovoSorb^® polyurethane biodegradable temporising matrix (plus plasma) as the scaffold (BTM-HSE). The graft analysis revealed PG-HSE-grafted wounds were fully epidermised in two weeks and the level of inflammatory markers, CXCl1, CXCl2, IL1β, and IL-6 transcripts, in grafts were at similar levels to their levels in autografts. This coincided with higher expression of COL1A2, COL3A1, and COL5A1 transcripts in PG-HSE grafts, compared to autografts and BTM-HSE grafts. Moreover, a higher deposition of both Col I and Col III was detected in the PG-HSE graft wound bed, when compared to the BTM-HSE graft wound bed. Conversely, BTM-HSE grafts showed a higher level of integrins, ITGA2, ITGA3, ITGA5, ITGA6, ITGAV, and ITGB1, at the RNA level, suggesting a stronger cell–scaffold interaction. In summary, we have shown although both PG and single layer BTM foam (plus plasma) are effective scaffolds for skin engineering, some key aspects of wound repair, including a reduction in inflammation and an increase in collagen deposition, are achieved with the platelet-derived hydrogel. The long-term effect of these scaffolds on wound scarring remains to be investigated. Full article

Impaired bone regeneration and wound healing represent a major clinical and socioeconomic challenge for our aging and multimorbid population. Fracture and wound healing share many common features, with transforming growth factor beta (TGF-β) being a key regulator of inflammation, angiogenesis, fibroblast activation, and matrix remodeling. The dysregulation of TGF-β signaling is a hallmark of chronic wounds, excessive scar formation, and fracture non-union. Extracellular matrix protein 1 (ECM1) plays a crucial role in the activation of latent TGF-β. As a protein of the extracellular matrix, ECM1 offers ideal conditions for the biofunctionalization of bone implants or wound patches. Its mode of action has been studied mainly in fibrosis models of the liver or heart, where TGF-β acts as a driver of the disease. The controlled knock-out or overexpression of ECM1 either promoted or improved fibrosis development. In this review, we discuss how these findings can be applied to the biofunctionalization of implants to support bone and wound healing, considering the impact of TGF-β on the different healing phases. Full article

Although extracellular vesicles (EVs) from mesenchymal stem cells have shown potential in skin wound repair, the diversity of EV sources and the optimization of delivery systems still need further exploration. This study is the first to demonstrate that extracellular vesicles from chemically induced mammary epithelial cells (CiMECs-EVs) possess distinct skin wound repair activity. To enhance the therapeutic efficacy of CiMECs-EVs and optimize their delivery efficiency, we innovatively combined them with a chitosan hydrogel to construct a composite repair system (CiMECs-EVs-chitosan hydrogel, CMECG). This system was then applied to a rat skin wound model. The results showed that CMECG significantly promoted the proliferation and migration of fibroblasts and mammary epithelial cells (MECs). In animal experiments, the relative wound closure efficiency of the control group was approximately 70% on day 14, while that of the CMECG group (loaded with 200 μg CiMECs-Exo) was enhanced to 90%, markedly accelerating the wound healing process. Histological analysis indicated that this system could effectively restore the structural continuity of various skin layers and significantly promote the synthesis and remodeling of collagen at the wound site. Mechanistically, the wound healing effect of CiMECs-EVs is closely associated with the endogenous miRNAs they encapsulate. These miRNAs can coordinately regulate cell proliferation, migration, and angiogenesis, modulate the inflammatory microenvironment, and inhibit excessive scar formation—thus regulating the entire repair process. This process involves multiple wound healing-related signaling pathways, including MAPK, PI3K-Akt, FoxO, TGF-β, and JAK-STAT. In summary, this study successfully constructed a novel EV-chitosan hydrogel repair system. This system is expected to provide an effective and innovative EV-based therapeutic strategy for the clinical treatment of skin wound repair. Full article

Background/Objectives: Osteoporosis is a prevalent and debilitating skeletal disease characterized by a progressive loss of bone mass and deterioration of bone microarchitecture. Probiotics have emerged as a potential therapeutic tool for treating osteoporosis through modulation of the gut microbiota. In this study, we aimed to examine the effects of live Lacticaseibacillus rhamnosus AC1 (LR-AC1), isolated from a fecal sample from a newborn in Hong Kong, on deoxycorticosterone acetate (DOCA)-induced bone loss in a rat model. Methods: Bone mass and microarchitecture were assessed using micro-computed tomography (micro-CT). Immunostaining for CD31⁺ and osterix, markers of endothelial cells and osteoblast precursors, respectively, was performed. Gut microbiota composition was analyzed via 16S rRNA sequencing. The effects of an LR-AC1 cell-free conditioned supernatant (CCS) on osteoclastogenesis, angiogenesis, and migration of bone marrow mesenchymal stem cells (BMSCs) were evaluated in vitro using RT-qPCR and wound healing assays. Results: LR-AC1 administration did not induce adverse effects in healthy rats; however, it exacerbated bone loss in rats with DOCA-salt-induced osteoporosis. Correspondingly, the number of CD31-positive endothelial cells and osterix-positive osteoprogenitors decreased with bone loss. In vitro, LR-AC1 CCS promoted osteoclastogenesis and angiogenesis, while in the presence of DOCA, LR-AC1 CCS inhibited BMSC migration. Gut microbiota analysis revealed that the relative abundances of the genera g_RF39 and g_Clostridia_UCG-014 correlated with the severity of bone loss. Conclusions: While several studies suggest that probiotics can prevent and treat osteoporosis, our findings indicate that in a male rat model of DOCA-salt-induced osteoporosis, live LR-AC1 aggravated bone loss. This effect is associated with alterations in gut microbiota and disruption of the coupling process in bone remodeling. Full article

Corneal fibrosis, a significant source of visual impairment, can result from keratocyte-to-myofibroblast transdifferentiation during wound healing. This study investigated the antifibrotic role of 1,25-dihydroxyvitamin D₃ (1,25 Vit D) and the lesser-known vitamin D, 24,25-dihydroxyvitamin D₃ (24,25 Vit D), in human and mouse corneal stromal cells (HSCs and MSCs) and in a Vit D receptor knockout (VDR KO) mouse model. Cells were treated with TGF-β1 ± Vit D metabolites and the expression of fibrotic and antifibrotic genes and proteins was evaluated. Both metabolites significantly reduced α-smooth muscle actin levels in HSCs, MSCs and organ-cultured mouse corneas (p < 0.05). They also upregulated the mRNA expression of BMP2, BMP6, BMPR2, and TGF-β3, as well as the protein expression of BMP6 and TGF-β3. VDR KO corneas subjected to alkali injury exhibited increased fibrotic responses and reduced CD45+ immune cell infiltration compared to wild-type controls. Notably, 24,25 Vit D exerted antifibrotic effects even in VDR KO cells, and the alternative 24,25 Vit D receptor FAM57B was expressed in all corneal cell layers. These results reveal consistent antifibrotic effects of both 1,25 and 24,25 Vit D across species, support the existence of VDR-independent mechanisms in the cornea, and offer new insights into potential therapeutic strategies for preventing corneal fibrosis. Full article

Background/Objectives: Postoperative complications such as wound infections and sepsis are common in diabetic patients, often resulting in longer hospital stays and higher morbidity. This study hypothesizes that a Random Forest Classifier can accurately predict these complications, enabling early clinical interventions. The model utilizes ensemble learning to integrate diverse patient data and improve predictive accuracy beyond traditional risk assessments. Methods: A comprehensive retrospective analysis was performed using data extracted from the National Surgical Quality Improvement Program (NSQIP) database. The dataset encompassed a wide array of variables, including demographic factors, clinical markers, and detailed surgical data (specialty, type of anesthesia, duration of surgery). Each variable was meticulously encoded into numerical formats, with categorical variables transformed through one-hot encoding, and continuous variables were normalized. The dataset was partitioned into training (80%) and testing (20%) subsets, ensuring a balanced representation of the target outcomes. The Random Forest Classifier was selected due to its robustness in handling high-dimensional data and its ability to model complex interactions between variables. Results: The Random Forest model showed accuracy rates of 94.38% for wound infection and 94.94% for sepsis. Precision and recall metrics also exceeded 94%, highlighting the model’s accuracy in identifying true positives and reducing false positives. ROC curve analysis yielded AUC values of 0.92 for wound infection and 0.95 for sepsis, indicating strong discriminative capability. Feature importance analysis further identified key predictors, including surgical duration, specific laboratory markers, and patient comorbidities. Conclusions: This study demonstrates the Random Forest Classifier’s strong predictive ability for postoperative wound infections and sepsis in diabetic patients. The model’s high-performance metrics indicate its potential for real-time risk stratification in clinical workflows. Future research should validate these findings in diverse populations and surgical settings. Incorporating this predictive model into clinical practice has the potential to significantly improve patient outcomes and reduce healthcare costs. Full article

As life expectancy continues to increase, age-related disorders are becoming more prevalent. Among these, vascular complications resulting from chronic inflammation are particularly concerning, as they impair angiogenesis and hinder tissue repair, both processes that heavily rely on a well-structured extracellular matrix (ECM). In this context, MicroMatrix^® UBM Particulate, a skin substitute composed of collagen, laminin, and proteoglycans, appears to offer properties conducive to tissue regeneration. The aim of this study was to evaluate the regenerative potential of MicroMatrix^® combined with the Secretome of human Dental Pulp Stem Cells (hDPSC-S), using the medicinal leech Hirudo verbana, a well-established model for studying wound healing, angiogenesis, and tissue regeneration. Adult leeches were injected with MicroMatrix^® either suspended in FBS-free medium (CTRL) or supplemented with hDPSC-S. 1-week post-treatment, the animals were sacrificed and subjected to morphological and immunohistochemical analyses. Our findings revealed that MicroMatrix^® successfully integrated into the leech body wall. Notably, when supplemented with hDPSC-S, there was a marked increase in cell infiltration, including telocytes and Hematopoietic Precursor Stem Cells, along with a significantly higher vessel density compared to CTRL. These results support the effectiveness of the cell-free device composed of MicroMatrix^® and hDPSC-S, highlighting its potential as a promising strategy for regenerative therapies aimed at treating complex wounds with poor vascularization. Full article

Wound healing is a dynamic process involving distinct phases that are regulated by cellular and molecular interactions. This review explores the fundamental mechanisms involved in wound healing, including the roles of cytokines and growth factors within the local microenvironment, with a particular focus on antimicrobial peptides (AMPs) as immune modulators and therapeutic agents in chronic wounds. Notably, AMPs such as LL-37 have been shown to reduce biofilm density by up to 60%, highlighting their dual role in both modulating host immune responses and combating persistent bacterial infections. It further examines emerging technologies that are transforming the field, extending beyond traditional biological mechanisms to innovations such as smart dressings, 3D bioprinting, AI-driven therapies, regenerative medicine, gene therapy, and organoid models. Additionally, the review addresses strategies to overcome bacterial biofilms and highlights promising approaches including biomaterials, nanomedicine, gene therapy, peptide-loaded nanoparticles, and the application of organoids as advanced platforms for studying and enhancing wound repair. Full article

Chronic wounds, such as diabetic ulcers, remain a significant clinical challenge due to high infection risk and delayed healing. This study presents a comprehensive evaluation of a novel wound dressing incorporating curcumin-functionalized silver–zinc oxide (Ag-ZnO) nanoparticles. The formulation was rationally designed based on molecular docking simulations that identified curcumin as a high-affinity ligand for Staphylococcus aureus Protein A. The synthesized nanoparticles demonstrated potent, broad-spectrum antibacterial activity, achieving complete inhibition of multidrug-resistant pathogens, including MRSA, within 60 s. A critical comparative assessment, incorporating an unloaded Ag-ZnO nanoparticle control group, was conducted in both a rabbit wound model and a randomized clinical trial (n = 75 patients). This design confirmed that the enhanced wound-healing efficacy is specifically attributable to the synergistic effect of curcumin combined with the nanoparticles. The curcumin-loaded Ag-ZnO treatment group showed a statistically significant reduction in healing time compared to both standard care and unloaded nanoparticle controls (e.g., medium wounds: 19.6 days vs. 90.6, p < 0.001). These findings demonstrate that curcumin-functionalized Ag-ZnO nanoparticles offer a safe and highly effective therapeutic strategy, providing robust antibacterial action and significantly accelerated wound healing. Full article

Various therapeutic approaches have been explored to speed up wound healing, with angiogenesis being a crucial factor in this process and skin repair. This study shows that a polysaccharide extracted from the red alga Osmundea pinnatifida (PSOP) can promote angiogenesis and accelerate healing. The structural properties of PSOP were investigated using various techniques, including scanning electron microscopy, X-ray diffraction, Fourier–transform infrared spectroscopy, ultraviolet–-visible spectroscopy, and high-performance liquid chromatography coupled with a refractive index detector. Additionally, the in vitro antioxidant activity of PSOP was evaluated using the reducing power assay, total antioxidant capacity measurement, and DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging tests. The PSOP extract exhibited significant pro-angiogenic effects in the avian chorioallantoic membrane model. Furthermore, the efficacy of PSOP-based hydrogels for wound healing was assessed in vivo using an excision wound model in Wistar rats. The results indicated accelerated wound healing, increased collagen deposition, and enhanced tissue regeneration. Computational studies suggest that the observed wound healing and pro-angiogenic effects may be attributed to the affinity of the PSOP units for cyclooxygenase-2 and vascular endothelial growth factor. These findings support the potential use of PSOP as a bioactive agent in wound care. Full article

Pasteurella multocida is a Gram-negative bacterium causing significant livestock diseases, like fowl cholera and hemorrhagic septicemia in cattle, and wound infection in humans. Classified into four subspecies and five capsular serotypes, it possesses multiple virulence factors, including capsular polysaccharides (CPSs), lipopolysaccharides (LPSs), outer membrane proteins (OMPs), iron acquisition proteins, and toxins that serve as vaccine targets. Antimicrobial treatment is challenging, so vaccination is key. Commercial vaccines include killed and live attenuated types, which are commonly used, though they have intrinsic problems. Advanced vaccines like recombinant subunit and DNA vaccines are emerging. Subunit vaccines targeting OMPs (OmpH, OmpA, PlpE, VacJ, and PmSLP) and recombinant Pasteurella multocida toxin (rPMT) show high efficacy in animal models, and their recombinant proteins induce strong immune responses. DNA vaccines have promise but limited use. The challenges in vaccine development are the strain diversity, short-term immunity, and inconsistent cross-protection. There is also a lack of research on recombinant and subunit vaccine development for small ruminants. Future research should focus on multivalent vaccines, optimization, including improving adjuvants and optimizing DNA vaccine delivery. Full article