Curcumin alleviates hypertrophic scarring by inhibiting fibroblast activation and regulating tissue inflammation

Wound treatment with curcumin prevents hypertrophic scarring and promotes remodeling by inhibiting fibroblast activation and regulating collagen deposition

More and more attention is paid to the prevention of hypertrophic scars (HS). This study aimed to investigate the mechanisms of topical curcumin application in alleviating HS secondary to wounds. Human dermal fibroblasts (HDFs) were cultured with transforming growth factor-β1 and varying concentrations of curcumin for 48 h. The proliferation activity, apoptosis and migration of HDFs were detected by CCK-8 assay, EdU assay, flow cytometry and wound healing assay, respectively. The expression of proteins implicated in fibroblast activation and collagen deposition was determined by Western blotting (WB). Curcumin (25 μmol/L, 28 days) was applied to rabbit ear wounds, and hypertrophic scarring was evaluated grossly and microscopically. We found that curcumin inhibited the proliferation and migration of HDFs and promoted cell apoptosis in a concentration-dependent manner. Curcumin at 10 and 25 μmol/L concentrations reduced the expression of Ki-67 and α-smooth muscle actin and increased cleaved caspase-3 expression and Bax/Bcl-2 ratio. Although the protein levels of collagen-I (COL-I), COL-III, matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were down-regulated, COL-III/COL-I and MMP-2/TIMP-1 ratios were maintained. Curcumin decreased the Manchester scar scale score, scar elevation index and collagen volume fraction of rabbit ear scars. Immunohistochemical results were generally consistent with the WB data. Unlike suppression of TIMP-1 in the entire region of the scar, curcumin reduced MMP-2 expression only in the edge part, which might be related to the alteration of cell polarity and orientation of fibroblasts. In conclusion, curcumin facilitates high-quality scars after wound healing by regulating fibroblast activation and collagen deposition.

LA-peptide Hydrogel-Regulation of macrophage and fibroblast fates and their crosstalk via attenuating TGF-β to promote scarless wound healing

The homeostasis of the wound microenvironment is fundamental for scarless wound healing, while the excessive accumulation of transforming growth factor-beta (TGF-β) in the wound microenvironment always leads to hypertrophic scars (HS) formation by regulating cell fates and crosstalk among various types of cells, such as macrophages and fibroblasts. This study reports that an injectable, self-assembling LA-peptide hydrogel has the potential to facilitate scarless cutaneous wound healing through dynamically adsorbing TGF-β within the wound environment. We found that the released LA peptides led to the suppression of both the PI3K/Akt and TGF-β/Smad2/3 pathways in macrophages and fibroblasts. As expected, the application of LA-peptide hydrogel alleviated the M2 type polarization of macrophages and inhibited fibroblasts activation by adsorbing TGF-β both in vitro and in vivo. Furthermore, designated concentrations of the LA-peptide hydrogel achieved controlled release of LA peptides, enabling dynamic regulation of TGF-β for maintaining microenvironment homeostasis during different phases of wound healing. This contributed to the inhibition of HS formation without delaying wound healing in both a mouse full-thickness skin wound model and a rabbit ear scar model. Overall, the LA-peptide hydrogel provides promising avenues for promoting scarless healing of wounds, exemplifying precision medicine-guided targeting of specific pathogenic molecules, such as TGF-β, and highlighting the significance of dynamic regulation of TGF-β homeostasis in wound microenvironment.

The role of macrophages in hypertrophic scarring: molecular to therapeutic insights

Hypertrophic Scar (HS) is a common fibrotic disease of the skin, usually caused by injury to the deep dermis due to trauma, burns, or surgical injury. The main feature of HS is the thickening and hardening of the skin, often accompanied by itching and pain, which seriously affects the patient's quality of life. Macrophages are involved in all stages of HS genesis through phenotypic changes. M1-type macrophages primarily function in the early inflammatory phase by secreting pro-inflammatory factors, while M2-type macrophages actively contribute to tissue repair and fibrosis. Despite advances in understanding HS pathogenesis, the precise mechanisms linking macrophage phenotypic changes to fibrosis remain incompletely elucidated. This review addresses these gaps by discussing the pathological mechanisms of HS formation, the phenotypic changes of macrophages at different stages of HS formation, and the pathways through which macrophages influence HS progression. Furthermore, emerging technologies for HS treatment and novel therapeutic strategies targeting macrophages are highlighted, offering potential avenues for improved prevention and treatment of HS.

Optimization of Metal-Based Nanoparticle Composite Formulations and Their Application in Wound Dressings

Metal-based nanoparticles (MNPs) have great potential for applications in wound healing and tissue engineering, and due to their unique structures, high bioactivities, and excellent designability characteristics, an increasing number of studies have been devoted to modifying these species to generate novel composites with desirable optical, electrical, and magnetic properties. However, few systematic and detailed reviews have been performed relating to the modification approaches available for MNPs and their resulting composites. In this review, a comprehensive summary is performed regarding the optimized modification formulations of MNPs for application in wound dressings, and the techniques used to prepare composite wound dressings are discussed. In addition, the safety profiles of the novel nanocomposite formulations and the limitations of the reported systems are evaluated. More importantly, a number of solution strategies are proposed to address these limitations. Overall, this review provides new ideas for the design of MNPs to facilitate their application in the field of skin tissue repair, and also looks into the future direction of MNPs in the biomedical field.

The Pathophysiology and Management of Pathologic Scarring-a Contemporary Review

Significance: Pathologic scarring occurs secondary to imbalances in the cellular mechanisms of wound healing and affects millions of people annually. This review article aims to provide a concise overview of the pathophysiology and management of pathologic scarring for clinicians and scientists alike. Recent Advances: Contemporary research in the field has identified aberrations in transforming growth factor-β/small mothers against decapentaplegic (TGF-β/SMAD) signaling pathways as key drivers of pathologic scar formation; indeed, this pathway is targeted by many treatment modalities and translational investigations currently underway. Although intralesional injection of corticosteroids has been the gold standard in the treatment of pathologic scarring, studies show greater treatment efficacy with the use of combination injections such as triamcinolone/5-fluorouracil and triamcinolone/botulinum toxin. Adjunctive therapies including ablative fractional carbon dioxide/erbium-doped yttrium aluminum garnet and non-ablative pulsed-dye lasers, microneedling, and carboxytherapy have shown encouraging results in small cohort studies. Translational investigations involving the use of nanogels, RNA interference, and small molecules targeting TGF-β/SMAD pathways are also currently underway and hold promise for the future. Critical Issues: The heterogeneous nature of hypertrophic scars and keloids poses significant challenges in formulating standardized treatment and assessment protocols, thereby limiting the conclusions that can be drawn. Future Directions: Rigorous clinical trials into the individual and synergistic effects of these therapies would be ideal before any definitive conclusions or evidence-based treatment recommendations can be made. Owing to the heterogeneity of the pathology and patient population, well-conducted cohort studies may be the next best option.

PAI-1 influences and curcumin destabilizes MMP-2, MMP-9 and basement membrane proteins during lung injury and fibrosis

One of the characteristic feature of idiopathic pulmonary fibrosis is an imbalanced fibrinolytic system. Plasminogen activator inhibitor-1 (PAI-1), an essential serine protease in the fibrinolytic system, has an anti-fibrotic tendency in some organs and a pro-fibrotic nature in others. Curcumin is reported to regulate the fibrinolytic system. In this study, we sought to determine how curcumin affected alterations in tissue remodelling mediated by PAI-1 in lung fibrosis. For in vitro studies, NIH3T3 fibroblasts were either exposed to TGF-β or overexpressed with PAI-1, and/or treated with curcumin. For in vivo studies, C57BL/6 mice were either instilled with bleomycin, overexpressed with PAI-1, and/or intervened with curcumin. Protein and gene expression studies were performed by western blotting and RT-PCR techniques, respectively. Curcumin intervention, in vitro and in vivo, could inhibit the the expression of collagen, fibronectin, MMP-2, and MMP-9, which was otherwise elevated by TGF-β or bleomycin. In conclusion, curcumin reduces pulmonary fibrosis by suppressing excessive basement membrane protein deposition and, likely, preventing the thickening of the alveolar septum.

Advancements in Dermatological Applications of Curcumin: Clinical Efficacy and Mechanistic Insights in the Management of Skin Disorders

Curcumin, derived from Curcuma longa (turmeric), exhibits significant potential in dermatology, addressing conditions like atopic dermatitis, psoriasis, chronic wounds, skin cancer, and infections through its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. This review synthesizes evidence on curcumin's mechanisms, including modulation of immune responses and promotion of wound healing, showcasing its efficacy in reducing inflammation, cytokine levels, and enhancing skin barrier functions. Studies highlight curcumin's ability to selectively target tumor cells, suggesting a multifaceted approach to cancer therapy with minimal side effects. Despite promising therapeutic benefits, challenges remain in bioavailability, potency, and targeted delivery, underscoring the need for further research to optimize dosages, delivery methods, and assess long-term safety. The integration of curcumin into dermatological practice requires a balanced consideration of evidence-based efficacy and safety. Curcumin's comprehensive utility in dermatology, coupled with the necessity for advanced scientific exploration, emphasizes the importance of combining traditional knowledge with contemporary research to improve patient care in dermatology. This approach could significantly enhance outcomes for individuals with skin-related conditions, marking curcumin as a versatile and promising agent in the field.

Possible benefits of food supplementation or diet in scar management: A scoping review

Aim

The evidence regarding a potential role of food supplementation as an adjunct therapy in scar aftercare is limited. In this scoping review we aim to provide an overview of the possible beneficial role of supplementations in aftercare settings.

Method

After formulating the research question and accompanying key words, a comprehensive search for relevant publications was performed using PubMed and Web of Science. Two authors independently identified and checked each study against the inclusion criteria. All data was collected and summarized for further discussion.

Results

After screening, 11 studies were included in the qualitative synthesis. Four studies including human subjects showed a promising connection between scar improvement and supplementation of vitamin D, omega-3 fatty-acids or a Solanaceae-free diet and lower omega-6 fatty-acid intake. Most of the studies were performed on in-vitro models. Preliminary evidence confirmed the beneficial role of vitamin D. Curcumin- and quercetin-supplementation were linked to decreased fibroblast proliferation. Vitamin C enhanced collagen production in healthy as well as keloidal dermal fibroblasts. Chitin stimulated cell-proliferation in human fibroblasts and keratinocytes.

Conclusion

The findings suggest early potential benefits of additional food supplementation in scar management for scars but provide no clear evidence. To establish guidelines or gather more evidence on food supplementation, studies involving human subjects (in vivo) are essential. The intricacies associated with nutritional studies in vivo present multifaceted challenges. It should be emphasized that substantial additional evidence is required before aspects such as timing and dosage of supplementation could be addressed for clinical application.

Lay Summary

Aim: This scoping review looks at whether taking food supplements might help with scar care alongside standard scar management following burn injury. Little information is thought to be available on this subject. An up-to-date review of the literature was undertaken to assimilate the body of evidence and determine if a consensus could be drawn.Method: A specific research question was designed and search conducted in scientific databases like PubMed and Web of Science. Two of our team members carefully selected and reviewed each study to determine which studies met the inclusion or exclusion criteria. All studies that met the inclusion criteria were then reviewed and the information collated to enable conclusions to be drawn.Results: Eleven studies met the inclusion criteria and were used to formulate the conclusions drawn. Four studies showed that taking vitamin D, omega-3 fatty acids, a diet without certain vegetables (Solanaceae), and eating less omega-6 fatty acids might help improve scars. It is important to note that most studies (seven out of 11) were carried out in a laboratory and not with real people. These lab studies showed that vitamin D might be helpful. Supplements like curcumin and quercetin seemed to slow down the growth of skin cells like fibroblasts and keratinocytes. Vitamin C aided collagen synthesis, which is important for healthy skin, in both normal and keloid scar cells. Another substance, chitin, was also found to help skin cells and keratinocytes grow better.Conclusion: Our findings point to some early possible benefits of taking extra nutrient supplements for managing scars but do not provide clear evidence. More research is required to enable the development of supplement recommendation and guidelines to be produced. Future research should focus on human trials but do keep in mind that carrying out supplement studies with people is more complicated. The evidence provided by this scoping review is insufficient to recommend the intake of any supplements or the imposition of dietary restrictions for the purpose of managing scars.