Search Results (191)

Platelet-rich plasma (PRP) is an autologous blood-derived concentrate increasingly utilized in regenerative medicine for its ability to accelerate healing and tissue repair. PRP is broadly classified by leukocyte content, fibrin architecture, and platelet concentration, with classification systems developed to standardize characterization. Preparation methods, including single- or double-spin centrifugation and buffy coat techniques, influence the final composition of PRP, determining the relative proportions of platelets, leukocytes, plasma proteins, and extracellular vesicles. These components act synergistically, with platelets releasing growth factors (e.g., VEGF, PDGF, TGF-β) that stimulate angiogenesis and matrix synthesis, leukocytes providing immunomodulation, plasma proteins facilitating scaffolding, and exosomes regulating intercellular signaling. Mechanistically, PRP enhances tissue repair through four key pathways: platelet adhesion molecules promote hemostasis and cell recruitment; immunomodulation reduces pro-inflammatory cytokines and favors M2 macrophage polarization; angiogenesis supports vascular remodeling and nutrient delivery; and serotonin-mediated pathways contribute to analgesia. These processes establish a regenerative microenvironment that supports both structural repair and functional recovery. Clinically, PRP has been applied across multiple specialties. In orthopedics, it promotes tendon, cartilage, and bone healing in conditions such as tendinopathy and osteoarthritis. In dermatology, PRP enhances skin rejuvenation, scar remodeling, and hair restoration. Gynecology has adopted PRP for ovarian rejuvenation, endometrial repair, and vulvovaginal atrophy. In dentistry and oral surgery, PRP accelerates wound closure and osseointegration, while chronic wound care benefits from its angiogenic and anti-inflammatory effects. PRP has also favored gingival recession coverage, regeneration of intrabony periodontal defects, and sinus grafting. Although preparation heterogeneity remains a challenge, PRP offers a versatile, biologically active therapy with expanding clinical utility. Full article

Skin scarring, including hypertrophic scars and keloids, often results from dysregulated collagen deposition during wound healing. Tropocollagen (TC), the soluble triple-helical precursor of collagen fibers, serves as the fundamental structural unit of the extracellular matrix (ECM) and plays a pivotal role in tissue repair. This review summarizes current knowledge on collagen and TC in wound healing, scar management, and regenerative dermatology. TC self-assembles into fibrils, providing structural support, while interacting with fibroblasts and growth factors such as transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) to regulate ECM remodeling, angiogenesis, and tissue regeneration. Various collagen preparations, including hydrolyzed collagen, gelatin, and native fibrillar forms, differ in molecular structure, bioavailability, and therapeutic applications. Emerging strategies, including collagen- and TC-based hydrogels, nanomaterial composites, and smart wound dressings, enhance stability, targeted delivery, and clinical efficacy. Despite promising preclinical and early clinical data, standardized preparations and robust randomized trials are needed to validate TC’s therapeutic potential and optimize its application in scar prevention and wound repair. Full article

Acute myocardial infarction (MI) is a major cardiovascular event and a leading cause of mortality worldwide. Beyond the initial ischemic injury, the inflammatory and immune responses play pivotal roles in both tissue damage and subsequent healing. While the anti-inflammatory strategies targeting neutrophil-driven injury have demonstrated potential in limiting early cardiac damage, growing evidence highlights the critical role of innate immune cells beyond the acute phase. Neutrophils, traditionally associated with tissue injury, also contribute to the resolution of inflammation and initiate key repair processes. Monocytes and macrophages follow a dynamic trajectory, transitioning from pro-inflammatory to reparative states, and play essential roles in debris clearance, angiogenesis, and scar formation. In the early inflammatory phase of acute MI, immune cells such as neutrophils and monocytes are rapidly recruited and activated. While they initially amplify inflammation through the release of pro-inflammatory mediators, their subsequent transition toward anti-inflammatory and reparative phenotypes helps limit tissue damage by clearing necrotic debris from the infarcted area and contributes to the resolution of inflammation. Accumulating evidence reveals a complex crosstalk between neutrophils and macrophages post-MI, with resident macrophages being involved in neutrophil recruitment, and neutrophil-derived signals participating in monocyte recruitment and macrophage polarization, thereby coordinating the spatial and temporal phases of cardiac repair. Understanding how neutrophil-derived mediators influence macrophage responses and whether macrophage-secreted factors reciprocally modulate neutrophil behavior opens promising pathways for developing targeted therapies to limit adverse remodeling following MI. Therefore, this review aims to (i) provide an overview of the roles of neutrophils and monocytes/macrophages in the pathophysiology of myocardial infarction, (ii) explore the mechanisms of communication, particularly via neutrophil-derived secreted factors, that influence monocyte/macrophage function and impact post-MI inflammation, repair, and remodeling, and (iii) highlight the potential therapies interfering with inflammation and neutrophil/macrophage cross-talk. Full article

Fractional laser photothermolysis, long established in dermatology, enables controlled microthermal injury that stimulates repair without scarring, but its potential in oral tissue regeneration has not been systematically explored. In this study, we conducted the first controlled experimental evaluation of a 1550 nm erbium fiber laser for oral mucosa regeneration. Thirty-two rabbits underwent fractional photothermolysis at energy levels of 70, 100 and 130 kJ, with gingival biopsies collected at 1, 14, 28 and 42 days for histological and immunohistochemical assessment of epithelial repair, stromal remodeling, inflammation and angiogenesis. All energy modes produced microcoagulation columns followed by progressive epithelial thickening, fibroblast proliferation and neoangiogenesis. The 70 kJ mode occasionally led to residual fibrosis, whereas higher energies (100–130 kJ) promoted effective connective tissue remodeling and de novo tissue formation without scarring. Complete epithelial recovery occurred within two weeks, indicating a safe and optimal interval for repeated exposure. Overall, the results demonstrate that 1550 nm fractional photothermolysis is a safe and effective method to induce regenerative responses in oral tissues, establishing a foundation for its translational application in periodontal and peri-implant regeneration. Full article

Wound healing is a delicately regulated pathophysiological process based on molecular, cellular, and tissue interactions. Mast cells (MCs) are involved in the reparative process in all phases of wound healing, which indicates their general significance in reparative processes. The structural and functional changes in the MCs during the healing process correspond to the phase of the wound process and determine its course. In the inflammatory phase, rapid whole-granular degranulation of MCs with the secretion of biologically active proinflammatory substances that have a stimulating effect on inflammatory cells prevailed. In the proliferation phase, the maximum number of MCs per unit area of wound tissue and the maximum degranulation index were noted. In the phase of granulated tissue remodeling, the amount and functional activity of MCs sharply decrease, which contributes to the completion of the healing process with the formation of a fully fledged normotrophic scar. The gradual degranulation of MCs was characteristic of the proliferation and remodeling phases. The treatment of purulent wounds with a drug from the polyhexamethylene guanidine group with the antiseptic polyhexanide 0.1% contributed to a temporary shift in the phases of the wound process while maintaining its general patterns, while the activation of the process occurred at an earlier time than in the control group of animals without local treatment. The results obtained showed that the use of a drug from the polyhexamethylene guanidine group with the antiseptic polyhexanide 0.1% for the treatment of purulent wounds quickly stops the inflammatory response and creates conditions for the development of the reparative abilities of granulation tissue cells, and primarily, mast cells. Full article

Background: Chronic inflammatory skin disorders, including atopic dermatitis, psoriasis, acne, and chronic wounds, affect nearly two billion people worldwide, impose substantial morbidity and economic burden, and remain only partially controlled by existing therapies. The cutaneous endocannabinoid system (ECS), comprising cannabinoid receptors, endocannabinoids, and their metabolic enzymes, regulates inflammation, pruritus, barrier integrity, and tissue repair; cannabinoid receptor type 2 (CB₂) has emerged as a particularly relevant target. β-Caryophyllene (BCP), a dietary sesquiterpene and highly selective CB₂ agonist with favorable safety and pharmacokinetic attributes, has attracted attention as a promising topical candidate. Methods: We systematically searched PubMed, Embase, and Web of Science (inception–30 July 2025) for studies on “β-caryophyllene” and dermatological outcomes, prioritizing purified BCP and analytically characterized BCP-rich fractions. Quantitative parameters, including tested concentration ranges (0.5 µM–10%) and principal mechanistic outcomes, were extracted to provide a translational context. Results: BCP penetrates the stratum corneum, suppresses NF-κB/MAPK and IL-4/TSLP pathways, enhances Nrf2-driven antioxidant defenses, and accelerates re-epithelialization and collagen remodeling. Across in vitro, in vivo, and formulation studies, BCP produced consistent anti-inflammatory and barrier-restorative effects within this concentration range. CB₂ antagonism attenuated these responses, confirming receptor specificity. BCP’s volatility and autoxidation to β-caryophyllene oxide (BCPO) necessitate stability-by-design strategies using antioxidants, low-oxygen processing, and protective packaging. Human evidence, limited to BCP-rich botanicals such as Copaifera oleoresins, suggests benefits for scars, wounds, and acne but lacks compound-specific validation. Conclusions: BCP exhibits coherent CB₂-mediated anti-inflammatory, antipruritic, antioxidant, and reparative actions with a favorable safety profile. Dose-defined, oxidation-controlled clinical trials of purified BCP are warranted to establish its potential as a steroid-sparing topical therapy. Full article

Background/Objectives: Myocarditis can occur in patients with coronavirus disease 2019 (COVID-19) as part of the systemic involvement of this infectious syndrome. The persistence of this non-ischemic late gadolinium enhancement (LGE) pattern can be considered an indicator of ongoing myocardial involvement or a sequela of myocarditis. We aimed to assess the effects of LGE on cardiac function and morphology in patients with COVID-19 admitted in intensive care unit for acute respiratory distress syndrome. Methods: Fifty patients (age 59 ± 11, female n = 15) were enrolled. Results: The prevalence of LGE was 33.3%. LGE was present in the lateral wall in all patients except for one, with LGE positivity at the interventricular septum. In general, patients with and without LGE had similar CMR variables values. In one case, LGE was associated with regional wall motion abnormality. The factor associated with LGE was the duration of hospitalization (7.97 ± 3.8 and 12.5 ± 6.7 days in patients without and with LGE, p = 0.007). Conclusions: LGE non-ischemic pattern was not associated with left ventricular dilatation or dysfunction or remodeling in patients with severe clinical manifestation of COVID-19. LGE is mainly present in patients with more prolonged duration of hospitalization. LGE may represent a residual scar with limited prognostic impact that larger multicenter studies could confirm. Full article

Background: The human acellular amniotic membrane (HAAM) is widely used as a decellularized bioscaffold in tissue engineering to promote wound healing, but its clinical application is limited by poor mechanical properties, rapid degradation, and handling difficulties. This study aimed to develop a modified amniotic membrane-based composite material loaded with vascular endothelial growth factor (VEGF) and the Notch signaling inhibitor N-[N-(3,5-difluorophenacetyl)-Lalanylhydrazide]-Sphenylglycine t-butyl ester (DAPT) to enhance wound healing by modulating macrophage polarization and cytokine secretion. Methods: VEGF-loaded gellan gum-hyaluronic acid (GG-HA) hydrogels (VEGF-GG-HA) and DAPT-loaded HAAM (DAPT-HAAM) were prepared and combined to form a novel composite material (VEGF-GG-HA & DAPT-HAAM). The morphology and microstructure of the materials were characterized using scanning electron microscopy. In vitro studies were conducted using the human monocytic cell line (Tohoku Hospital Pediatrics-1, THP-1) to evaluate the effects of the materials on cell viability, cytokine secretion, and protein expression. Assessments included CCK-8 assays, ELISA, quantitative real-time PCR, Western blot analysis, and immunohistochemical staining. Results: The composite material VEGF-GG-HA & DAPT-HAAM exhibited good biocompatibility and significantly promoted THP-1 cell proliferation compared to control and single-component groups. It enhanced the secretion of IL-10, TNF-α, TGF-β, MMP1, and MMP3, while suppressing excessive TGF-β overexpression. The material also modulated macrophage polarization, showing a trend toward anti-inflammatory M2 phenotypes while maintaining pro-inflammatory signals (e.g., TNF-α) for a balanced immune response. Conclusions: The modified amniotic membrane hydrogel composite promotes wound healing through a phased immune response: it modulates macrophage polarization (balancing M1 and M2 phenotypes), enhances cytokine and matrix metalloproteinase secretion, and controls TGF-β levels. These effects contribute to improved vascular remodeling, reduced fibrosis, and prevention of scar formation, demonstrating the potential for enhanced wound management. Full article

Fascia, once considered a passive connective covering, is now recognized as a mechanosensitive tissue and stem cell niche with roles in regeneration, ECM remodeling, and immune–vascular regulation. The aim of this review was to synthetize evidence of fascia-derived progenitors and their mechanobiological functions across in vitro, preclinical and clinical domains. A systematic search of PubMed, Scopus and Web of Science (up to August 2025) was performed in accordance with PRIMS guidelines. Eligible studies addressed fascia in relation to stem/progenitor cells and regenerative outcomes. Risk of bias was assessed with OHAT criteria for in vitro studies, SYRCLE for animal studies and ROBINS-I for clinical studies. Of 648 records identified, 34 studies were included, encompassing 17 in vitro, 17 animal and 4 clinical investigations, with overlap across domains, and 3 reviews. In vitro, fascia-derived stem cells (FDSCs), FAPs and ASCs were shown to remodel ECM, promote angiogenesis and respond to mechanical cues. Animal models revealed collective fibroblast migration as ECM patches, regulated by N-cadherin, Connexin43 and p120-catenin, while CD201+ progenitors directed scar formation. Clinical studies, though few, reported improved outcomes with subfascial PRP injections and adipofascial flaps. Fascia appears as an active mechanobiological hub and stem cell reservoir that may influence tissue repair and fibrosis, although current evidence, particularly from clinical studies, remains preliminary. Despite promising insights, evidence is limited by methodological heterogeneity, emphasizing the need for mechanistic human studies and well-powered clinical trials. 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

Spinal cord injury (SCI) poses a substantial physical, psychological and social burden. Although many therapies are currently available, it is still impossible to fully restore the lost organic functions of SCI patients. An important event in SCI physiopathology is the development of a neuron-repulsive fibrotic scar at the lesion site, a barrier that hampers neuronal growth and contributes to long-term functional impairment. This neuron-repulsive scar is present in severe spinal cord injuries in humans but is absent in some animals capable of natural regeneration. In humans and other mammals, various immune cells take part in the development and maturation of the glial scar, and cytokines and other molecular factors regulate the associated histologic changes. Pro-inflammatory cytokines and complement system proteins tend to be overexpressed early after SCI, but anti-inflammatory cytokines also participate in the remodelling of the injured tissue by regulating the excessively pro-inflammatory environment. This inflammatory regulation is not entirely successful in humans, and inflammation inhibitor drugs offer promising avenues for SCI treatment. Some non-specific immunosuppressor drugs have already been studied, but targeted modulation therapies may be more efficient and less prone to secondary effects. Continued experimental research and clinical trials are vital to advance findings and develop effective treatments, aiming to overcome the barriers to spinal cord regeneration and improve recovery for SCI patients. Full article

Background: Scar management remains a significant challenge in plastic and reconstructive surgery, particularly when addressing atrophic, retractile, or fibrotic scars. Autologous fat grafting and hybrid fractional laser therapy have independently shown efficacy in improving scar quality. This study aims to evaluate the synergistic effect of their combination on clinical and functional scar outcomes. Methods: A prospective, comparative study was conducted on patients with cutaneous scars of various etiologies. Participants were treated with either hybrid fractional laser therapy alone (CO₂ and 1570 nm Erbium-glass wavelengths) or a combined protocol of laser plus autologous lipofilling. Clinical outcomes were assessed at baseline and at 30, 60, and 90 days post-treatment using the Vancouver Scar Scale (VSS), patient satisfaction scores, and Visual Analog Scale (VAS) for pain and discomfort. Results: Patients receiving the combined treatment demonstrated significantly greater improvement in scar pigmentation, elasticity, pliability, and thickness compared to those treated with laser alone. Subjective symptoms, including pain and itching, were also more effectively alleviated. The volumetric and regenerative properties of adipose tissue, particularly its content of adipose-derived stem cells (ADSCs) and stromal vascular fraction (SVF), likely contributed to the enhanced outcomes observed. Conclusions: The combination of hybrid fractional laser therapy and autologous lipofilling offers a superior therapeutic strategy for scar remodeling compared to laser monotherapy. This integrated regenerative approach addresses both structural and biological aspects of scar tissue, making it a valuable protocol for personalized and effective scar management. Further randomized trials with larger sample sizes and histological validation are warranted to confirm these preliminary findings and refine therapeutic protocols. Full article

Fibrosis is a pathological process characterized by the excessive accumulation of extracellular matrix (ECM), particularly collagen, leading to tissue scarring, architectural distortion, and organ dysfunction. While fibrosis is a physiological component of wound healing, its persistence and dysregulation can drive chronic tissue damage and organ dysfunction. In autoimmune diseases, fibrosis arises from prolonged inflammation and immune system dysregulation, creating a vicious cycle that exacerbates tissue injury and promotes disease progression. This review provides a comprehensive overview of the fibrotic processes across a range of immune-mediated and autoimmune conditions, including systemic sclerosis (SSc), morphea, autoimmune hepatitis (AIH), systemic lupus erythematosus (SLE), Sjögren’s syndrome (SS), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA), Finally, we discuss current and emerging antifibrotic strategies aimed at interrupting pathological ECM remodeling and restoring tissue homeostasis. Full article

Keloids are characterized by excessive extracellular matrix (ECM) accumulation and persistent inflammation, leading to disfiguring scars and poor therapeutic outcomes. The α7 nicotinic acetylcholine receptor (α7nAChR) has emerged as a key modulator of inflammatory and fibrotic signaling. This study evaluated the antifibrotic effects of tropisetron, a clinically available α7nAChR agonist, in keloid fibroblasts (KFs) and a rat incisional scar model. In vitro, KFs exhibited reduced α7nAChR expression, which was restored by tropisetron in a dose-dependent manner. Tropisetron treatment significantly decreased KF viability, downregulated pro-fibrotic genes (COL1A1, COL3A1, α-SMA), and upregulated matrix metalloproteinases (MMP1 and MMP3). Additionally, it suppressed phosphorylation of Smad2/3 and reduced expression of NF-κB and TNF-α, indicating inhibition of both TGF-β and inflammatory pathways. In vivo, tropisetron-treated rats showed a ~40% reduction in scar area, improved collagen organization, and increased α7nAChR expression in scar tissue. Western blot analysis confirmed decreased levels of collagen I, p-Smad2/3, α-SMA, NF-κB, and TNF-α. These results indicate that tropisetron exerts dual antifibrotic and anti-inflammatory effects through α7nAChR-mediated signaling and enhanced ECM remodeling. This study provides the first evidence supporting α7nAChR activation as a promising therapeutic strategy for managing keloids and other fibrotic skin disorders. Full article