Keloids and scars: a review of keloids and scars, their pathogenesis, risk factors, and management

Chemotherapy affects the development of pathological scarring after general thoracic surgery in children

Globally, a great number of children have been suffering from physical dysfunction and psychological stress due to uncontrollable scar growth and a lack of effective modalities. Despite chemotherapy's established role as a primary treatment for pathological scarring in adults, its efficacy in preventing or minimizing scar formation in paediatric patients remains underexplored. This retrospective cohort study aimed to refine the relevant clinical evidence and investigate the effect of chemotherapy on pathological scars in children. In this single-centre retrospective cohort study, the data of children aged ≤18 years who underwent thoracic surgery at the Children's Hospital of Fudan University between 1 January 2018, and 31 December 2021 were assessed. The primary outcome was pathological scarring, and the secondary outcomes were subjective symptoms accompanying pathological scarring, such as pain and itching. To mitigate indication bias, analysis was performed by inverse probability weighting (IPTW) log-binomial regression models. The cohort comprised 102 children, among whom 36 received adjuvant chemotherapy perioperatively, while 66 did not. Under the IPTW model, a statistically significant difference in pathological scarring incidence was observed between the chemotherapy and non-chemotherapy groups (16.7% vs. 29.4%, p = 0.027). And the children received chemotherapy post-operatively had a lower relative risk of pathological scarring, compared with those received chemotherapy both before and after surgery (19.8% vs. 28.8%). Adjuvant chemotherapy treatment after surgery may reduce the incidence of post-operative pathological scarring in children.

A Single-Institution Review of the Use of Radiation in the Adjuvant and Definitive Management of Keloids

AIMS

Many individuals suffer from keloids that are refractory to standard treatment modalities, including surgical excision alone. Radiation therapy can be used to reduce the risk of recurrent keloids post-operatively, as well as be used as primary treatment for keloids not amenable to surgical resection. The purpose of this study was to review our institutional experience of radiation therapy for keloid management.

MATERIALS AND METHODS

A retrospective review of patients treated with radiation therapy for keloids between 2014 and 2020 at our institution was performed.

RESULTS

A total of 70 keloids in 41 patients were treated. For the 55 keloids treated with post-operative radiation therapy (16Gy delivered in 2 fractions), 82.5% (33/40) of evaluable lesions did not recur. Among the 15 keloids treated with definitive radiation therapy (24Gy delivered in 3 fractions), 78.6% (11/14) of evaluable keloids showed complete flattening, and 14.3% (2/14) had partial flattening. Both acute and late toxicities were mild, with only a single instance of grade 3 toxicity (dermatitis).

CONCLUSION

Our study confirms that radiation therapy has a role in reducing the risk of keloid recurrence post-operatively, and plays an important role in the definitive management of unresectable keloids.

VR23 and Bisdemethoxycurcumin Enhanced Nanofiber Niche with Durable Bidirectional Functions for Promoting Wound Repair and Inhibiting Scar Formation

Chronic wounds pose a significant clinical challenge worldwide, which is characterized by impaired tissue regeneration and excessive scar formation due to over-repair. Most studies have focused on developing wound repair materials that either facilitate the healing process or control hyperplastic scars caused by over-repair, respectively. However, there are limited reports on wound materials that can both promote wound healing and prevent scar hyperplasia at the same time. In this study, VR23-loaded dendritic mesoporous bioglass nanoparticles (dMBG) are synthesized and electrospun in poly(ester-curcumin-urethane)urea (PECUU) random composite nanofibers (PCVM) through the synergistic effects of physical adsorption, hydrogen bond, and electrospinning. The physicochemical characterization reveals that PCVM presented matched mechanical properties, suitable porosity, and wettability, and enabled sustained and temporal release of VR23 and BDC with the degradation of PCVM. In vitro experiments demonstrated that PCVM can modulate the functions and polarization of macrophages under an inflammatory environment, and possess effective anti-scarring potential and reliable cytocompatibility. Animal studies further confirmed that PCVM can efficiently promote re-epithelialization and angiogenesis and reduce excessive inflammation, thereby remarkably accelerating wound healing while preventing potential scarring. These findings suggest that the prepared PCVM holds promise as a bidirectional regulatory dressing for effectively promoting scar-free healing of chronic wounds.

Long Non-Coding RNA B3GALT5-AS1 Suppresses Keloid Progression by Regulating the β-Trcp1-Mediated Ubiquitination of HuR

Background

lncRNA β‑1,3‑galactosyltransferase 5‑AS1 (B3GALT5-AS1) plays a vital regulatory role in colon and gastric cancers. However, the biological functions and regulatory mechanisms of B3GALT5-AS1 in keloid progression remain unknown. This study aims to investigate the molecular mechanisms in the B3GALT5-AS1-regulated keloid proliferation and invasion.

Methods

Secondary mining of the lncRNA sequencing data from GSE158395 was conducted to screen differentially expressed lncRNAs between keloid and normal tissues. MTT, cell migration and invasion assays were performed to detect the effects of B3GALT5-AS1 on keloid fibroblasts (KFs) proliferation and metastasis. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were also determined to evaluate glycolysis in KFs. RNA pull-down and RNA-protein immunoprecipitation assays were used to confirm the interaction between B3GALT5-AS1 and Hu-Antigen R (HuR). Further ubiquitination and rescue experiments were performed to elucidate the regulatory relationship between B3GALT5-AS1 and HuR.

Results

B3GALT5-AS1 was significantly down-regulated in keloid tissues and fibroblasts. B3GALT5-AS1 overexpression significantly inhibited KFs proliferation, glycolysis, invasion, and migration and promoted cell apoptosis, whereas silencing B3GALT5-AS1 inhibited these effects. Moreover, B3GALT5-AS1 binds to HuRand reduces its stability through β-Transducin repeats-containing protein 1 (β-Trcp1)-mediated ubiquitination. Overexpression of HuR reversed the inhibition of B3GALT5-AS1 on cell proliferation, migration, and invasion in KFs, where glycolysis pathway was involved.

Conclusion

Our findings illustrate that B3GALT5-AS1 has great effect on inhibition of keloid formation, which provides a potential target for keloid therapy.

Differential Photosensitivity of Fibroblasts Obtained from Normal Skin and Hypertrophic Scar Tissues

It is unclear whether normal human skin tissue or abnormal scarring are photoreceptive. Therefore, this study investigated photosensitivity in normal skin tissue and hypertrophic scars. The expression of opsins, which are photoreceptor proteins, in normal dermal fibroblasts (NDFs) and hypertrophic scar fibroblasts (HSFs) was examined. After exposure to blue light (BL), changes in the expression levels of αSMA and clock-related genes, specifically PER2 and BMAL1, were examined in both fibroblast types. Opsins were expressed in both fibroblast types, with OPN3 exhibiting the highest expression levels. After peripheral circadian rhythm disruption, BL induced rhythm formation in NDFs. In contrast, although HSFs showed changes in clock-related gene expression levels, no distinct rhythm formation was observed. The expression level of αSMA was significantly higher in HSFs and decreased to the same level as that in NDFs upon BL exposure. When OPN3 knocked-down HSFs were exposed to BL, the reduction in αSMA expression was inhibited. This study showed that BL exposure directly triggers peripheral circadian synchronization in NDFs but not in HSFs. OPN3-mediated BL exposure inhibited HSFs. Although the current results did not elucidate the relationship between peripheral circadian rhythms and hypertrophic scars, they show that BL can be applied for the prevention and treatment of hypertrophic scars and keloids.

Influence of scar age, laser type and laser treatment intervals on paediatric burn scars: a systematic review and meta-analysis

Background

Laser therapy has emerged to play a valuable role in the treatment of paediatric burn scars; however, there is heterogeneity in the literature, particularly concerning optimal timing for initiation of laser therapy. This study aims to investigate the effect of factors such as scar age, type of laser and laser treatment interval on burn scar outcomes in children by meta-analysis of previous studies.

Methods

A literature search was conducted across seven databases in May 2022 to understand the effects of laser therapy on burn scar outcomes in paediatric patients by metanalysis of standardized mean difference (SMD) between pre- and post-laser intervention. Meta-analyses were performed using the Comprehensive Meta-Analysis software version 4.0. Fixed models were selected when there was no significant heterogeneity, and the random effects model was selected for analysis when significant heterogeneity was identified. For all analyses, a p-value < 0.05 was considered significant.

Results

Seven studies were included in the meta-analysis with a total of 467 patients. Laser therapy significantly improved Vancouver Scar Scale (VSS)/Total Patient and Observer Scar Assessment Scale (Total POSAS), vascularity, pliability, pigmentation and scar height of burn scars. Significant heterogeneity was found between the studies and thus subgroup analyses were performed. Early laser therapy (<12 months post-injury) significantly improved VSS/POSAS scores compared to latent therapy (>12 months post-injury) {SMD -1.97 [95% confidence interval (CI) = -3.08; -0.87], p < 0.001 vs -0.59 [95%CI = -1.10; -0.07], p = 0.03} as well as vascularity {SMD -3.95 [95%CI = -4.38; -3.53], p < 0.001 vs -0.48 [95%CI = -0.66; -0.30], p < 0.001}. Non-ablative laser was most effective, significantly reducing VSS/POSAS, vascularity, pliability and scar height outcomes compared to ablative, pulse dye laser and a combination of ablative and pulse dye laser. Shorter treatment intervals of <4 weeks significantly reduced VSS/POSAS and scar height outcomes compared to intervals of 4 to 6 weeks.

Conclusions

Efficacy of laser therapy in the paediatric population is influenced by scar age, type of laser and interval between laser therapy application. The result of this study particularly challenges the currently accepted initiation time for laser treatment. Significant heterogeneity was observed within the studies, which suggests the need to explore other confounding factors influencing burn scar outcomes after laser therapy.

The efficacy of adipose-derived stem cells in burn injuries: a systematic review

BACKGROUND

Burn injuries can be associated with prolonged healing, infection, a substantial inflammatory response, extensive scarring, and eventually death. In recent decades, both the mortality rates and long-term survival of severe burn victims have improved significantly, and burn care research has increasingly focused on a better quality of life post-trauma. However, delayed healing, infection, pain and extensive scar formation remain a major challenge in the treatment of burns. ADSCs, a distinct type of mesenchymal stem cells, have been shown to improve the healing process. The aim of this review is to evaluate the efficacy of ADSCs in the treatment of burn injuries.

METHODS

A systematic review of the literature was conducted using the electronic databases PubMed, Web of Science and Embase. The basic research question was formulated with the PICO framework, whereby the usage of ADSCs in the treatment of burns in vivo was determined as the fundamental inclusion criterion. Additionally, pertinent journals focusing on burns and their treatment were screened manually for eligible studies. The review was registered in PROSPERO and reported according to the PRISMA statement.

RESULTS

Of the 599 publications screened, 21 were considered relevant to the key question and were included in the present review. The included studies were almost all conducted on rodents, with one exception, where pigs were investigated. 13 of the studies examined the treatment of full-thickness and eight of deep partial-thickness burn injuries. 57,1 percent of the relevant studies have demonstrated that ADSCs exhibit immunomodulatory effects during the inflammatory response. 16 studies have shown improved neovascularisation with the use of ADSCs. 14 studies report positive influences of ADSCs on granulation tissue formation, while 11 studies highlight their efficacy in promoting re-epithelialisation. 11 trials demonstrated an improvement in outcomes during the remodelling phase.

CONCLUSION

In conclusion, it appears that adipose-derived stem cells demonstrate remarkable efficacy in the field of regenerative medicine. However, the usage of ADSCs in the treatment of burns is still at an early experimental stage, and further investigations are required in order to examine the potential usage of ADSCs in future clinical burn care.

Ear Keloid as an Unusual Complication of Prolonged Mask Use during the COVID-19 Pandemic

The recent COVID-19 pandemic required many people to wear ear-loop face masks (ELFMs) for protracted periods, and ear injuries have been reported. Here, we report a rare case of a keloid on the right posterior ear that appeared to arise from prolonged ELFM use. A 76-year-old Japanese man presented with a 7.3 × 2.2 × 1.4-cm keloid running from the medial retroauricular sulcus to the posterior lobule. The lack of keloid history suggested the absence of genetic risk factors. The patient reported extensive mask-wearing habits that were augmented by the pandemic. The keloid developed from an ear injury. Although it healed well, it started thickening 2 months later. Because local mechanical forces (eg, pressure/friction) can promote keloid growth, the ELFM may have provoked the keloid. The patient disclosed a history of uncontrolled hypertension and diabetes mellitus, which associate with severe keloids. The whole keloid was removed via total excision, and the defect was closed primarily and subjected to 15Gy/2Fr radiotherapy. The patient was advised to use a different mask type. Twelve months later, the scar had healed without complications or recurrence and with good cosmetic outcomes. Thus, ELFMs can promote retroauricular keloid formation, possibly by imposing local pressure/friction. ELFMs may also raise local skin temperatures and humidity, thereby fostering infection, which can trigger keloids. Hypertension/diabetes may further elevate the risk of EFLM-induced keloid. Thus, an auricular keloid is an unusual complication of prolonged ELFM use. Combination therapy can have excellent outcomes. Patients with keloid risk factors should be advised to use face masks without ear loops.

Aloe vera peel-derived nanovesicles display anti-inflammatory properties and prevent myofibroblast differentiation

BACKGROUND

Aloe vera (AV) is a medicinal plant, most known for its beneficial effects on a variety of skin conditions. Its known active compounds include carbohydrates and flavonoids such as quercetin and kaempferol, among others. In the past decade, plant nanovesicles (NVs) have gained considerable interest as interkingdom communicators, presenting an opportunity for clinical standardization of natural products. In this study, we aimed to assess the potential of AVpNVs for the treatment of burn wounds.

METHODS

AVpNVs were isolated and characterized regarding vesicle yield (nanoparticle tracking analysis) and structure (transmission electron microscopy and atomic force microscopy), as well as their protein content with proteomics. We assessed key characteristics for treating burn wounds in vitro, such as the anti-inflammatory potential in LPS-stimulated macrophages and keratinocytes, and the effect of AVpNVs on myofibroblast differentiation and contraction.

KEY FINDINGS

AVpNVs presented a homogenous NV population, vesicular shape, and NV-associated protein markers. AVpNVs significantly decreased the secretion of pro-inflammatory cytokines TNFα, IL-1β, and IL-6. Furthermore, AVpNVs inhibited myofibroblast differentiation and significantly decreased their contractile potential in collagen matrices. Observed effects were linked to proteins identified in the isolates through proteomics analysis.

CONCLUSION

AVpNVs displayed characteristics as an inflammatory modulator, while simultaneously diminishing myofibroblast differentiation and contraction. Novel strategies for burn wound treatment seek to decrease scarring on a cellular and molecular level in the early stages of wound healing, which makes AVpNVs a promising candidate for future plant-vesicle-based treatments.

Cytologic, histopathologic, and immunohistochemical features of keloidal fibroma in a dog

A five-year-old male English Bulldog was presented with a firm, well-circumscribed, 1 cm in diameter cutaneous mass on the left flank. Fine-needle aspiration (FNA) biopsy samples were collected for cytologic analysis. Cytology revealed a highly cellular sample consisting of spindle cells, numerous bundles of thick, glassy eosinophilic material (hyalinized collagen), and inflammatory cells. Spindle cells showed moderate anisocytosis and anisokaryosis, had oval nuclei with coarsely stippled chromatin, 1-3 prominent round nucleoli, and moderate amounts of wispy cytoplasm. Cells were occasionally associated with an eosinophilic extracellular matrix. Binucleated and trinucleated spindle cells were often noted. Low numbers of macrophages, small lymphocytes, and individual well-granulated mast cells were also present. The lesion was excised and submitted for histopathologic examination, revealing a well-delineated, nonencapsulated mass composed of hyalinized collagen fibers separated by spindle-shaped mesenchymal cells in the deep dermis and subcutis. Mild anisocytosis and anisokaryosis and less than one mitosis per 10 × high power fields were present. Excision of the mass was complete. The findings were consistent with a keloidal fibroma, a rare benign variant of fibroma. Neoplastic cells showed positive immunoreactivity for vimentin, and a small-to-moderate number of tumor cells showed positive immunoreactivity for α-smooth muscle actin. This is the first cytologic description of a keloidal fibroma correlated with histopathologic findings and immunolabeling. In cases where keloidal neoplasia is suspected, and since moderate cellular atypia can be present on cytologic examination even in cases of keloidal fibroma, histopathologic examination is necessary to differentiate between keloidal fibroma and keloidal fibrosarcoma.

Centella triterpenes cream as a potential drug for the treatment of hypertrophic scar through inhibiting the phosphorylation of STAT3: A network pharmacology analysis and in vitro experiments

BACKGROUND

Hypertrophic scars (HS) often affect the normal function and appearance of the skin and bring adverse effects to the body and mind of patients, being a challenge in the fields of burns and plastic surgery as well as rehabilitation. Despite significant efficacy of centella triterpenes cream for treating HS clinically, its pharmacodynamics and molecular targets are still unclear. Therefore, the network pharmacology analysis combined with in vitro cell molecular biology experiments was used to explore the mechanism and targets of centella triterpenes cream treating HS in this study.

METHODS

First, target genes of asiaticoside (AC) were obtained from the databases including the Comparative Toxicogenomics Database, similarity ensemble approach, SwissTargetPrediction and TargetNet, and HS targets were acquired from the databases like Disgenet, GeneCards, and Online Mendelian Inheritance in Man. The common targets of AC-HS were obtained through plotting a Venn diagram. Subsequently, STRING 11.0 was employed for analyzing the protein-protein interaction (PPI) network of the common targets, and cytoscape 3.9.0 for analyzing the connectivity of PPI and plotting the network diagram of "drug-component-target". Additionally, a modified tissue culture method was applied to separate primary normal fibroblasts (NFs) in human skin and hypertrophic scar fibroblasts (HSFs). HSFs after 24-h AC treatment were subjected to MTT assay to detect cell viability, scratch assay to assess cell migration ability, and western blot to test the protein expression levels of STAT3, p-STAT3, transforming growth factor-β1 (TGF-β1), collagen I (COL 1), fibronectin 1 (FN1), and alpha-smooth muscle actin (α-SMA).

RESULTS

In network pharmacology analysis, 134 pharmacodynamic targets of AC and 2333 HS targets were obtained after retrieving the database, 50 AC-HS common targets were obtained by a Venn diagram, and a total of 178 edges and 13 core genes such as JUN and STAT3 were acquired by PPI analysis. In vitro experiments showed that the phosphorylation level of STAT3 (p-STAT3) was increased in HSFs. In addition to reducing p-STAT3 in HSFs, AC significantly inhibited the cell viability and migration of HSFs and downregulated the protein levels of TGF-β1, COL 1, FN 1, and α-SMA.

CONCLUSION

STAT3 can be activated in HS. AC may exert its pharmacological effects of inhibiting TGF-β1 signal transduction and regulating extracellular matrix remodeling in HS by inhibiting STAT3 phosphorylation. However, the specific molecular mechanism of AC remains to be verified through further experiments.

Recurrence rates in the treatment of keloids and hypertrophic scars with intralesional triamcinolone combined with other intralesional agents

Hypertrophic scars (HTS) and keloids are pathologic scars that are products of a wound healing pathway error attributed to genetic and inflammatory causes (Leventhal et al., Arch Facial Plast Surg 8(6):362-368. https://doi.org/10.1001/archfaci.8.6.362 , 2006). Methods of pathologic scar treatment include intralesional agents, cryotherapy, surgical excision, pressure dressings, topical agents, laser resurfacing, radiotherapy, and other investigational therapies (Leventhal et al. 2006). The recurrence of pathologic scar is high across all treatment modalities, including the use of intralesional agents (Trisliana Perdanasari et al., Arch Plast Surg 41(6):620-629. https://doi.org/10.5999/aps.2014.41.6.620 , 2014). In the treatment of pathologic scar, combination approaches using intralesional agents, such as triamcinolone (TAC), 5-fluorouracil (5FU), verapamil (VER), bleomycin (BLM), and botulinum toxin (BTX), are superior therapies when compared to monotherapy (Yosipovitch et al., J Dermatol Treat 12(2):87-90. https://doi.org/10.1080/095466301317085363 , 2001; Yang et al., Front Med 8:691628. https://doi.org/10.3389/fmed.2021.691628 , 2021; Sun et al., Aesthetic Plast Surg 45(2):791-805. https://doi.org/10.1007/s00266-019-01570-8 , 2021). This review assesses recurrence and the reporting of recurrence in pathologic scar after treatment with intralesional triamcinolone (TAC) in combination with another intralesional agent. A literature review was conducted using research journals from PubMed using the following search terms: [(keloid) AND (triamcinolone) AND (combination) AND (intralesional)], as well as [(keloid) AND (triamcinolone) AND (combination)]. Articles were reviewed and included if the article analyzed  or compared intralesional agents for pathologic scar treatment within the last 10 years. The average follow-up period of included articles (n = 14) that utilized combination intralesional therapy (TAC-X) was approximately 11 months (range 1-24 months). Consistent recurrence rate reporting across studies was lacking. The combination agent with the highest recurrence rate was TAC-5FU (23.3%). The range of reported recurrence rates was 7.5-23.3%. Six studies using various intralesional combination regimens reported 0% recurrence over the follow-up period (TAC-5FU, TAC-BTX, TAC-BLM, TAC-CRY). Three studies did not report recurrence rates. While the efficacy of combination therapy is typically assessed via scar scales, the assessment of recurrence across studies of combination therapy is inconsistent and inadequate, with truncated follow-up periods. While scar recurrence can take place during 1-year post-treatment, long-term follow-up (18-24 months) is needed to characterize recurrence in the treatment of pathologic scar using various intralesional agents. Long-term follow-up periods allow patients to receive accurate prognostic information regarding recurrence after combination intralesional therapy. There are limitations to this review in that comparisons were made across studies with varying outcome variables, including scar size, injection concentration and interval, and follow-up period. Standardized follow-up periods and recurrence rate reporting are integral to furthering the understanding of these therapies and enhancing patient care.

Targeting the Angiotensin Pathway in the Treatment of Cutaneous Fibrosis: A Systematic Review

Acting on the renin-angiotensin-aldosterone system, angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) are mechanisms of some of the most prescribed medications in the world. In addition to their routine use for the treatment of hypertension, such agents have gained attention for their influence on the angiotensin receptor pathway in fibrotic skin disorders, including scars and keloids. To evaluate the current level of evidence supporting the use of these agents, a systematic review related to ACE-Is/ARBs and cutaneous scarring was conducted. We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from database inception through January 26, 2022. Two independent reviewers identified eligible studies for inclusion and extracted data. Data were insufficient for meta-analysis and are presented narratively. Of 461 citations identified, seven studies were included (199 patients). The studies included two randomized clinical trials, one comparative observation study, and four case reports. All the included studies reported statistically significant improvement in cutaneous scarring in patients using ACE-Is/ARBs compared with that in those treated with placebo/control using various outcome measures such as scar size and scar scales. However, much of the literature on this subject to date is limited by study design.

5-Aminolevulinic Acid Photodynamic Therapy Combined with Intralesional Triamcinolone and 5-Fluorouracil to Treat Acne Hypertrophic Scar

Background

Acne is a chronic inflammatory disease of the pilosebaceous unit. Improper treatment of acne can lead to skin lesions in some people. Acne hypertrophic scar is relatively rare, but it significantly affects the appearance and beauty, and usually has a great psychological and social impact on patients.

Objective

To evaluate the clinical efficacy and safety of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) combined with 5-fluorouracil (5-FU) injection and triamcinolone acetonide (TAC) solution in the treatment of acne hypertrophic scars.

Methods

This article included 13 outpatients with acne accompanied by acne hypertrophic scar who were treated from September 2018 to September 2022. All patients received ALA-PDT combined with intralesional injection of 5-FU and TAC. At first, patients received ALA-PDT once every two weeks. After the third ALA-PDT, 5-FU and TAC were mixed in a ratio of 3:7, and then immediately injected in the local scars. The effect was observed after 1 month. If the effect is not obvious, a further injection of 5-FU and TAC to the lesion is necessary. The patients were followed up for 6 months. The Vancouver Scars Scale (VSS) was used to evaluate the efficacy before and after treatment and photos of patients were collected.

Results

After ALA-PDT combined with intralesional 5-FU and TAC, all patients achieved good clinical efficacy. 23.08% of patients received one local injection and 76.92% received two local injections. After treatment, the scar lesions were reduced and flattened, and the scars became soft. The total score of VSS after treatment was significantly lower than before, and the difference was statistically significant (P<0.05). The main adverse reactions were pain, erythema, and pigmentation, which can subside within 3 weeks. There was no recurrence after 6 months of follow-up.

Conclusion

ALA-PDT combined with intralesional injection of 5-FU and TAC significantly affects acne hypertrophic scars, which is worthy of further in-depth and large-scale research.

20(R)-ginsenoside Rg3-loaded polyurethane/marine polysaccharide based nanofiber dressings improved burn wound healing potentials

The management of deep burn injuries is extremely challenging, ascribed to their delayed wound healing rate, susceptibility for bacterial infections, pain, and increased risk of hypertrophic scarring. In our current investigation, a series of composite nanofiber dressings (NFDs) based on polyurethane (PU) and marine polysaccharides (i.e., hydroxypropyl trimethyl ammonium chloride chitosan, HACC and sodium alginate, SA) were accomplished by electrospinning and freeze-drying protocols. The 20(R)-ginsenoside Rg3 (Rg3) was further loaded into these NFDs to inhibit the formation of excessive wound scars. The PU/HACC/SA/Rg3 dressings showed a sandwich-like structure. The Rg3 was encapsulated in the middle layers of these NFDs and slowly released over 30 days. The PU/HACC/SA and PU/HACC/SA/Rg3 composite dressings demonstrated superior wound healing potentials over other NFDs. These dressings also displayed favorable cytocompatibility with keratinocytes and fibroblasts and could dramatically accelerate epidermal wound closure rate following 21 days of the treatment of a deep burn wound animal model. Interestingly, the PU/HACC/SA/Rg3 obviously reduced the excessive scar formation, with a collagen type I/III ratio closer to the normal skin. Overall, this study represented PU/HACC/SA/Rg3 as a promising multifunctional wound dressing, which promoted the regeneration of burn skins and attenuated scar formation.

Influence of scar age, laser type and laser treatment intervals on adult burn scars: A systematic review and meta-analysis

AIM

The study aims to identify whether factors such as time to initiation of laser therapy following scar formation, type of laser used, laser treatment interval and presence of complications influence burn scar outcomes in adults, by meta-analysis of previous studies.

METHODS

A literature search was conducted in May 2022 in seven databases to select studies on the effects of laser therapy in adult hypertrophic burn scars. The study protocol was registered with PROSPERO (CRD42022347836).

RESULTS

Eleven studies were included in the meta-analysis, with a total of 491 patients. Laser therapy significantly improved overall VSS/POSAS, vascularity, pliability, pigmentation and scar height of burn scars. Vascularity improvement was greater when laser therapy was performed >12 months (-1.50 [95%CI = -2.58;-0.42], p = 0.01) compared to <12 months after injury (-0.39 [95%CI = -0.68; -0.10], p = 0.01), the same was true for scar height ((-1.36 [95%CI = -2.07; -0.66], p<0.001) vs (-0.56 [95%CI = -0.70; -0.42], p<0.001)). Pulse dye laser (-4.35 [95%CI = -6.83; -1.86], p<0.001) gave a greater reduction in VSS/POSAS scores compared to non-ablative (-1.52 [95%CI = -2.24; -0.83], p<0.001) and ablative lasers (-0.95 [95%CI = -1.31; -0.59], p<0.001).

CONCLUSION

Efficacy of laser therapy is influenced by the time lapse after injury, the type of laser used and the interval between laser treatments. Significant heterogeneity was observed among studies, suggesting the need to explore other factors that may affect scar outcomes.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Treatment and Improvement of Healing after Surgical Intervention

The development of abnormal scars has a great impact on people's well-being, and improving scarring outcomes after surgery is a field that currently lacks consensus. This review aims to identify newly researched approaches to improving the quality of surgical scars. A systematic search of PubMed, Scopus, Web of Science, and ScienceDirect was conducted between 13 May 2023 and 17 May 2023, in accordance with the recommendations of the PRISMA Statement. Study selection and analysis of methodological quality were performed in parts, independently and blindly, based on eligibility criteria. The 21 prospective, comparative, and randomized studies reviewed included 1057 subjects and studied approaches such as topical applications of creams with herbal extracts and silicone gels, growth factors, negative pressure dressings, oligonucleotides, intralesional injection of compounds such as botulinum toxin, skin closure techniques such as suturing and tissue adhesive, and laser treatments. There are recent research techniques that generate good results and are really promising to improve the results of surgical scars; however, the available evidence is extremely limited in some cases, and it is necessary to deepen its analysis to obtain reliable action protocols in each type of surgery.

Assessment of the quality of the healing process in experimentally induced skin lesions treated with autologous platelet concentrate associated or unassociated with allogeneic mesenchymal stem cells: preliminary results in a large animal model

Regenerative medicine for the treatment of skin lesions is an innovative and rapidly developing field that aims to promote wound healing and restore the skin to its original condition before injury. Over the years, different topical treatments have been evaluated to improve skin wound healing and, among them, mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) have shown promising results for this purpose. This study sought to evaluate the quality of the healing process in experimentally induced full-thickness skin lesions treated with PRP associated or unassociated with MSCs in a sheep second intention wound healing model. After having surgically created full-thickness wounds on the back of three sheep, the wound healing process was assessed by performing clinical evaluations, histopathological examinations, and molecular analysis. Treated wounds showed a reduction of inflammation and contraction along with an increased re-epithelialization rate and better maturation of the granulation tissue compared to untreated lesions. In particular, the combined treatment regulated the expression of collagen types I and III resulting in a proper resolution of the granulation tissue contrary to what was observed in untreated wounds; moreover, it led to a better maturation and organization of skin adnexa and collagen fibers in the repaired skin compared to untreated and PRP-treated wounds. Overall, both treatments improved the wound healing process compared to untreated wounds. Wounds treated with PRP and MSCs showed a healing progression that qualitatively resembles a restitutio ad integrum of the repaired skin, showing features typical of a mature healthy dermis.

Spring-Powered Needle-Free Injection of Triamcinolone Acetonide and 5-Fluorouracil for Keloid Treatment

Introduction

Keloid is an abnormal fibroproliferative healing response characterized by excessive and invasive tissue growth beyond the wound boundaries. The conventional treatment involves injecting drugs such as triamcinolone acetonide (TA), 5-fluorouracil (5-FU), or their combination intralesionally. However, the pain associated with injections often leads to low patient compliance and treatment failure. The spring-powered needle-free injector (NFI) provides an affordable alternative option for drug delivery with reduced pain.

Case

This case report presents a 69-year-old female patient with a keloid treated using a spring-powered needle-free injector (NFI) for drug delivery. The keloid was assessed using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). The patient's pain level was measured using the Numeric Pain Rating Scale (NPRS). TA and 5-FU mixed with lidocaine were loaded into the NFI and injected at a dose of 0.1 mL/cm². The treatment was repeated twice a week. After four sessions, the keloid flattened by 0.5 cm, VSS score decreased from 11 to 10, and POSAS scores decreased from 49 to 43 (observer) and from 50 to 37 (patient). The NPRS during each procedure was 1, indicating minimal pain.

Discussion

The spring-powered NFI is a simple and cost-effective device that operates based on Hooke's law, producing a high-pressure fluid jet for effective skin penetration. The NFI demonstrated effectiveness in treating keloid lesions, resulting in visible improvement after four treatments.

Conclusion

The spring-powered NFI offers an affordable and painless alternative to keloid treatment.

Epidemiological and clinical features of hypertrophic scar and keloid in Chinese college students: A university-based cross-sectional survey

Background

Hypertrophic scar (HS) and keloid (KD) are common dermal fibroproliferative growth caused by pathological wound healing. HS's prevalence is currently undetermined in China. Though it primarily occurs in dark-skinned individuals, KD can develop in all races, and its prevalence among Chinese people is poorly documented.

Objective

To explore the present epidemiological status of them in Chinese college students.

Methods

We conducted a university-based cross-sectional study at one university in Fujian, China. A total of 1785 participants aged 16-34 years (mean age, 20.0 ± 2.0; 58.7% female) were enrolled and statistical analyses were performed.

Results

HS and KD were observed in 5.2% (95% confidence interval [CI]: 4.2-6.2) and 0.6% (95% CI: 0.3-1.0) of the population respectively. There was a significant difference by sex in HS (P < 0.05), but not in KD. The prevalence of HS and KD both showed a significant difference by age (P < 0.05), but not in ethnic and native place distribution. The occurrence of HS and KD were both concentrated in individuals 9-20 years old (HS: 77.2%; KD: 81.8%). They were mainly distributed in the upper limbs (52.1%; 64.3%), and the main cause was trauma (51.0%; 35.7%). In addition, male sex was a risk factor for HS (adjusted P < 0.001), and KD was associated with age ≥22 years and family history (adjusted P < 0.050).

Conclusion

HS and KD are common in Chinese college students, and more attention and research is warranted.

Nanoemulsions Based on Sunflower and Rosehip Oils: The Impact of Natural and Synthetic Stabilizers on Skin Penetration and an Ex Vivo Wound Healing Model

Vegetable oils offer excellent biological properties, but their high lipophilicity limits their bioavailability. This work aimed to develop nanoemulsions based on sunflower and rosehip oils and to evaluate their wound-healing activity. The influence of phospholipids of plant origin on nanoemulsions’ characteristics was investigated. A nanoemulsion prepared with a mixture of phospholipids and synthetic emulsifiers (Nano-1) was compared with another prepared only with phospholipids (Nano-2). The healing activity was evaluated in wounds induced in human organotypic skin explant culture (hOSEC) based on histological and immunohistochemical analysis. The hOSEC wound model was validated, showing that high nanoparticle concentration in the wound bed interferes with cell mobility and the ability to respond to the treatment. Nanoemulsions were 130 to 370 nm, with a concentration of 1013 particles/mL, and a low potential to induce inflammatory processes. Nano-2 was three times larger than Nano-1 but less cytotoxic and could target the oils to the epidermis. Nano-1 permeated intact skin to the dermis and showed a more prominent healing effect than Nano-2 in the hOSEC wound model. Changes in the lipid nanoemulsion stabilizers impacted the cutaneous and cellular penetration of the oils, cytotoxicity, and healing kinetics, resulting in versatile delivery systems.

Therapeutic and prophylactic effects of radiation therapy in the management of recurrent granulation tissue induced tracheal stenosis: a review on the role of Endobronchial brachytherapy and external beam radiation therapy

PURPOSE

Granulation tissue-induced tracheal stenosis (mainly secondary to intubation or lung transplantation) is one of the most common etiologies of benign airway obstructions. Recurrence rates after standard treatment options (surgical resection and/or endobronchial interventions) can inadvertently worsen the stricture through the stimulation of more granulation tissue generation (via increased fibroblast activity and roliferation). Low-dose radiotherapy could be a promising tool to prevent granulation tissue formation after surgery and/or endobronchial interventions regarding its established role in the treatment of keloids or hypertrophic scars, two benign diseases with similar a pathophysiology to tracheal stenosis. This study reviews case reports and small series that used endobronchial brachytherapy (EBBT) or external beam radiotherapy (EBRT) for the management of refractory granulation tissue-induced tracheal stenosis after surgery and/or endobronchial interventions.

METHODS AND MATERIALS

Case reports and series (published up to October 2022) that reported outcomes of patients with recurrent granulation tissue-induced tracheal stenosis (after surgery and/or endobronchial interventions) treated by EBBT or EBRT (in definitive or prophylactic settings) were eligible.

RESULTS

Sixteen studies (EBBT: nine studies including 69 patients, EBRT: seven studies including 32 patients) were reviewed. The pooled success rate across all studies was 74% and 97% for EBBT and EBRT, respectively.

CONCLUSIONS

Radiation therapy appears to be effective in the management of selected patients with recurrent/refractory tracheal stenosis. Response to this treatment is usually good, but further studies with a larger number of patients and long-term followup are necessary to determine the optimal technique, dose, and timing of radiation therapy, late complications, the durability of response, and criteria for patient selection.

Hypertrophic Scars of the Hand: The Role of Electrophotobiomodulation Theory as a Recent Line of Treatment

BACKGROUND

A more enduring strategy for the treatment of hypertrophic scars of the hand is still a challenge facing restorative dermatologists and plastic surgeons. Nonetheless, with the use of nonablative devices, intense pulsed light and different types of lasers have started to yield promising outcomes and are close to becoming an effective and dependable technique. The advances in radiofrequency energy have brought new life to optical-based frameworks. Radiofrequency current delivers an unadulterated heat effect according to the electrical response characteristics of each tissue. The purpose of this study was to assess the patient satisfaction, safety, and clinical efficacy of the use of electrophotobiomodulation (combined intense pulsed light and radiofrequency energy) in the treatment of postburn hypertrophic scars of the hand.

METHODS

This was a prospective clinical study that was performed on 56 patients who presented with postburn hypertrophic scars on the hands between March of 2013 and January of 2020.

RESULTS

The clinical appraisal showed excellent results in 33 patients (58.9%), good results in 18 patients (32.2%), fair results in five patients (8.9%), and no poor results.

CONCLUSION

The use of radiofrequency energy combined with intense pulsed light was effective for the treatment of hand scars on people with various skin tones.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Silicone gel sheeting for treating keloid scars

BACKGROUND

Keloid scarring is one of the most common types of pathological scarring. Keloid scars that fail to heal can affect a person's physical and psychological function by causing pain, pruritus, contractures, and cosmetic disfigurement. Silicone gel sheeting (SGS) is made from medical-grade silicone reinforced with a silicone membrane backing and is one of the most commonly used treatments for keloid scars. However, there is no up-to-date systematic review assessing the effectiveness of SGS for keloid scars. A clear and rigorous review of current evidence is required to guide clinicians, healthcare managers and people with keloid scarring.

OBJECTIVES

To assess the effectiveness of silicone gel sheeting for the treatment of keloid scars compared with standard care or other therapies.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was December 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that recruited people with any keloid scars and assessed the effectiveness of SGS.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment, data extraction and GRADE assessment of the certainty of evidence. We resolved initial disagreements by discussion, or by consulting a third review author when necessary.

MAIN RESULTS

Two studies met the inclusion criteria. Study sample sizes were 16 and 20 participants. The trials were clinically heterogeneous with differences in causes for scarring (e.g. surgery, infected wounds, and trauma), site (e.g. chest and back), and ages of scars. The duration of follow-up was three and four and a half months. The included studies reported three comparisons; SGS compared with no treatment, SGS compared with non-silicone gel sheeting (a dressing similar to SGS but which does not contain silicone), and SGS compared with intralesional injections of triamcinolone acetonide. One trial had a split-body design and one trial had an unclear design (resulting in a mix of paired and clustered data). The included studies reported limited outcome data for the primary review outcome of scar severity measured by health professionals and no data were reported for severity of scar measured by patients or adverse events. For secondary outcomes some data on pain were reported, but health-related quality of life and cost-effectiveness were not reported. Both trials had suboptimal outcome reporting, thus many domains in the risk of bias were assessed as unclear. All evidence was rated as being very low-certainty, mainly due to risk of bias, indirectness, and imprecision.  SGS compared with no treatment Two studies with 33 participants (76 scars) reported the severity of scar assessed by health professionals, and we are uncertain about the effect of SGS on scar severity compared with no treatment (very low-certainty evidence, downgraded once for risk of bias, once for inconsistency, once for indirectness, and once for imprecision). We are uncertain about the effect of SGS on pain compared with no treatment (21 participants with 40 scars; very low-certainty evidence, downgraded once for risk of bias, once for inconsistency, once for indirectness, and once for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness. SGS compared with non-SGS One study with 16 participants (25 scars) was included in this comparison. We are uncertain about the effect of SGS on scar severity assessed by health professionals compared with non-SGS (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). We are also uncertain about the effect of SGS on pain compared with non-SGS (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness. SGS compared with intralesional injections of triamcinolone acetonide One study with 17 participants (51 scars) reported scar severity assessed by health professionals, and we are uncertain about the effect of SGS on scar severity compared with intralesional injections of triamcinolone acetonide (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). This study also reported pain assessed by health professionals among 5 participants (15 scars) and we are uncertain about the effect of SGS on pain compared with intralesional injections of triamcinolone acetonide (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and twice for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness.

AUTHORS' CONCLUSIONS

There is currently a lack of RCT evidence about the clinical effectiveness of SGS in the treatment of keloid scars. From the two studies identified, there is insufficient evidence to demonstrate whether the use of SGS compared with no treatment, non-SGS, or intralesional injections of triamcinolone acetonide makes any difference in the treatment of keloid scars. Evidence from the included studies is of very low certainty, mainly driven by the risk of bias, indirectness, and imprecision due to small sample size. Further well-designed studies that have good reporting methodologies and address important clinical, quality of life and economic outcomes are required to reduce uncertainty around decision-making in the use of SGS to treat keloid scars.

Impact of internal mammary artery perforator propeller flaps combined with radiotherapy in the treatment of large chest keloids: Our experience

Background

Keloids are benign skin hyperplasias but have a tumor-like appearance. Clinical management of keloids remains challenging.

Aims

We retrospectively evaluated the safety and efficacy of internal mammary artery perforator propeller flaps combined with timely radiotherapy in the treatment of large chest keloids.

Methods

From June 2017 to May 2020, 25 patients with large chest keloids (average size 4.82 cm ± 2.53 cm × 9.04 cm ± 4.86 cm) who received both radiotherapy and internal mammary artery perforator flaps transplantation in our department were included. After surgical removal of the keloids, various propeller flaps based on the unilateral internal mammary artery were designed and applied to repair the defects. Timely and full-dose radiotherapy was performed for these patients after the operation.

Results

After keloid resection, the dimensions of the defect area were 3 cm-15 cm × 4 cm-25 cm, and the sizes of the flaps were 3 cm-16 cm × 4 cm-27 cm. For all 25 patients, the flaps survived, and the incisions healed in one stage. During the follow-up (median 18 months), no local recurrence was observed, and the itching and pain symptoms in the scar area were significantly relieved. Both physicians and patients were satisfied with the results.

Conclusions

The application of internal mammary artery perforator propeller flaps combined with radiotherapy in the treatment of chest keloids can effectively reduce the recurrence of keloids and relieve the related symptoms. It also has advantages including minimized donor site damage, short operation time and speedy postoperative recovery, suggesting its great clinical value.

Lesion Site Is the Key Prognostic Factor for Keloid Patients Receiving Surgery With Adjuvant Radiotherapy

BACKGROUND

Keloid is a benign tumor with high recurrence rate; accordingly, complete surgical excision with adjuvant radiotherapy is one of the most effective treatments. This study reviewed outcomes of keloid patients receiving surgery and adjuvant radiotherapy in Kaohsiung Medical University Hospital.

MATERIALS AND METHODS

All patients received radiation dose with 15 Gy, with their first radiotherapy within 24 hours after surgical excision. The end points were recurrence rate and local recurrence-free interval (LRFI), defined clinically as palpable gross tumor over the treatment site and duration from the last day of radiotherapy to disease recurrence.

RESULTS

From May 2017 to July 2020, 32 patients with 40 keloid lesions were included. The mean age for these patients was 37.6 years, and the median follow-up time was 15.3 months. The overall recurrence rate was 52.5%, and the median LRFI was 9.7 months. Recurrence rates for males and females were 46.7% and 56% ( P = 0.567), respectively; for head and ear, chest, shoulder and upper extremities, and abdomen and back were 12.5%, 61.5%, 63.6%, and 62.5% ( P = 0.093); for lesions over 20 cm 2 and below 20 cm 2 were 62.5% and 50% ( P = 0.527); and for megavoltage electron beam and kilovoltage photon beam were 56.7% and 40% ( P = 0.361), respectively. Patients were further classified into 2 groups by lesion sites, which showed lower recurrence rate ( P = 0.011) and longer LRFI ( P = 0.028) with lesions over the head and ear than other sites.

CONCLUSIONS

We found that lesion site might be a prognostic factor for keloid recurrence. Adjuvant radiation dose escalation for high-recurrence risk areas (other than the head and ear) might be required.

Effect of hydrogen intervention on refractory wounds after radiotherapy: A case report

BACKGROUND

Patients with keloids who receive radiotherapy (RT) after surgery can develop refractory wounds that cannot be healed by the patient's own repair system. Such chronic wounds are uneven and complex due to persistent abscess and ulceration. Without external intervention, they can easily result in local tissue necrosis or, in severe cases, large area tissue resection, amputation, and even death.

CASE SUMMARY

This article describes the use of hydrogen to treat a 42-year-old female patient with a chronic wound on her left shoulder. The patient had a skin graft that involved implanting a dilator under the skin of her left shoulder, and then transferring excess skin from her shoulder onto scar tissue on her chest. The skin grafting was followed by two rounds of RT, after which the shoulder wound had difficulty healing. For six months, the patient was treated with 2 h of hydrogen inhalation (HI) therapy per day, in addition to application of sterile gauze on the wound and periodic debridement. We also performed one deep, large, sharp debridement to enlarge the wound area. The wound healed completely within 6 mo of beginning the HI treatment.

CONCLUSION

After HI therapy, the patient showed superior progress in reepithelialization and wound repair, with eventual wound closure in 6 mo, in comparison with the previous failures of hyperbaric oxygen and recombinant bovine basic fibroblast growth factor therapies. Our work showed that HI therapy could be a new strategy for wound healing that is cleaner, more convenient, and less expensive than other therapies, as well as easily accessible for further application in clinical wound care.

Single-Cell RNA-Sequencing Reveals the Cellular and Genetic Heterogeneity of Skin Scar to Verify the Therapeutic Effects and Mechanism of Action of Dispel-Scar Ointment in Hypertrophic Scar Inhibition

Hypertrophic scarring (HS), caused by excessive fibrosis of injured skin, imposes a psychological burden and creates a source of distress that impairs the quality of life of affected individuals. However, the gold standard for HS treatment has not yet been determined due to the complicated and difficult nature of the routines and procedures involved. Previous studies have indicated that the topical application of certain active components found in traditional Chinese medicines shows potential as a therapeutic alternative for scars. Here, single-cell RNA-sequencing was performed to determine cellular heterogeneity and identify marker genes and mechanisms associated with HS. It was found that fibroblasts comprise the largest proportion of HS cell types. The marker genes that were highly expressed in fibroblasts were extracellular matrix (ECM)-related, whereas ECM-receptor interactions and the transforming growth factor (TGF)-β signalling pathway were also found to be active. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, which was applied to identify the molecular compounds of Dispel-Scar Ointment (DSO), revealed 74 effective chemical components belonging to 14 types of constituents, such as flavonoids, tanshinones, salvianolic acids, glycosides, and phthalides. Furthermore, in vivo studies using rat scar models showed that the topical application of Salvia miltiorrhiza, Ligusticum chuanxiong, peach kernel, safflower, and motherwort exerted beneficial effects on fibroblasts. DSO promoted scar maturation and reduced scar areas, its efficacy being similar to that of topically applied silicone. Functional studies using immunofluorescence staining, western blotting, and quantitative real-time polymerase chain reaction demonstrated that DSO may target the TGF-β/Smad pathway to inhibit collagen synthesis and promote ECM remodelling. However, further in vitro mechanistic research and single-drug prescription studies may be required to identify the specific effective compound or active ingredient of DSO, which would provide more substantial evidence regarding the potential therapeutic value of traditional herbs in HS.

Nuclear medicine in the management of superficial skin abnormalities and institutional experience

Keloid, hypertrophic scars and basal cell carcinoma (BCC) falls under the category of non-melanoma skin cancer. Intralesional steroids, external beam radiation therapy, 5-Fluorouracil, cryotherapy, laser, etc are the available treatment options. However, recurrence has been reported with each type of treatment mode. In the present article, various treatment modes have been discussed and institutional experience of Rhenium-188 skin patches for the treatment of keloids and BCC has been discussed.

The Polygenic Map of Keloid Fibroblasts Reveals Fibrosis-Associated Gene Alterations in Inflammation and Immune Responses

Due to many inconsistencies in differentially expressed genes (DEGs) related to genomic expression changes during keloid formation and a lack of satisfactory prevention and treatment methods for this disease, the critical biomarkers related to inflammation and the immune response affecting keloid formation should be systematically clarified. Normal skin/keloid scar tissue-derived fibroblast genome expression data sets were obtained from the Gene Expression Omnibus (GEO) and ArrayExpress databases. Hub genes have a high degree of connectivity and gene function aggregation in the integration network. The hub DEGs were screened by gene-related protein–protein interactions (PPIs), and their biological processes and signaling pathways were annotated to identify critical biomarkers. Finally, eighty-one hub DEGs were selected for further analysis, and some noteworthy signaling pathways and genes were found to be closely related to keloid fibrosis. For example, IL17RA is involved in IL-17 signal transduction, TIMP2 and MMP14 activate extracellular matrix metalloproteinases, and TNC, ITGB2, and ITGA4 interact with cell surface integrins. Furthermore, changes in local immune cell activity in keloid tissue were detected by DEG expression, immune cell infiltration, and mass CyTOF analyses. The results showed that CD4+ T cells, CD8+ T cells and NK cells were abnormal in keloid tissue compared with normal skin tissue. These findings not only support the key roles of fibrosis-related pathways, immune cells and critical genes in the pathogenesis of keloids but also expand our understanding of targets that may be useful for the treatment of fibrotic diseases.

Dermal Fibroblast Heterogeneity and Its Contribution to the Skin Repair and Regeneration

Significance: Dermal fibroblasts are the major cell type in the skin's dermal layer. These cells originate from distinct locations of the embryo and reside in unique niches in the dermis. Different dermal fibroblasts exhibit distinct roles in skin development, homeostasis, and wound healing. Therefore, these cells are becoming attractive candidates for cell-based therapies in wound healing. Recent Advances: Human skin dermis comprises multiple fibroblast subtypes, including papillary, reticular, and hair follicle-associated fibroblasts, and myofibroblasts after wounding. Recent studies reveal that these cells play distinct roles in wound healing and contribute to diverse healing outcomes, including nonhealing chronic wound or excessive scar formation, such as hypertrophic scars (HTS) and keloids, with papillary fibroblasts having antiscarring and reticular fibroblast scar-forming properties. Critical Issues: The identities and functions of dermal fibroblast subpopulations in many respects remain unknown. In this review, we summarize the current understanding of dermal fibroblast heterogeneity, including their defined cell markers and dermal niches, dynamic changes, and contributions to skin wound healing, with the emphasis on scarless healing, healing with excessive scars (HTS and keloids), chronic wounds, and the potential application of this heterogeneity for developing cell-based therapies that allow wounds to heal faster with less scarring. Future Directions: Heterogeneous dermal fibroblast populations and their functions are poorly characterized. Refining and advancing our understanding of dermal fibroblast heterogeneity and their participation in skin homeostasis and wound healing may create potential therapeutic applications for nonhealing chronic wounds or wounds that heal with excessive scarring.

OMICS Approaches Evaluating Keloid and Hypertrophic Scars

Abnormal scar formation during wound healing can result in keloid and hypertrophic scars, which is a major global health challenge. Such abnormal scars can cause significant physiological pain and psychological distress and become a financial burden. Due to the biological complexity of scar formation, the pathogenesis of such scars and how to prevent them from forming remains elusive. In this review paper, we delve into the world of "omics" approaches to study abnormal scars and provide examples of genomics, transcriptomics, proteomics, epigenomics, and metabolomics. The benefits of "omics" approaches are that they allow for high-throughput studies and the analysis of 100s to 1000s of genes and proteins with the accumulation of large quantities of data. Currently in the field, there is a lack of "omics" review articles describing pathological scars. In this review, we summarize genome-wide linkage analysis, genome-wide association studies, and microarray data to name a few omics technologies. Such data can provide novel insights into different molecular pathways and identify novel factors which may not be captured through small-scale laboratory techniques.

Single-port transaxillary robotic thyroidectomy (START): 200-cases with two-step retraction method

Background

This study aims to report the results of a pioneering clinical study using the single-port transaxillary robotic thyroidectomy (START) for 200 patients with thyroid tumor and to introduce our novel two-step retraction method.

Methods

START was performed on consecutive 200 patients using the da Vinci Single-Port (SP) robot system from January 2019 to September 2020 at the Yonsei University Health System, Seoul, Korea. The novel two-step retraction technique, in which a 3.5 cm long incision is made along the natural skin crease, was used for the latter 164 patients. The surgical outcome and invasiveness of the SP two-step retraction method were analyzed.

Results

Among the 200 cases who underwent START, 198 were female and 2 were male, with a mean age of 34.7 (range: 13–58 years). Thyroid lobectomy was performed for 177 patients and total thyroidectomy was performed for 23 patients. Ten patients had benign thyroid nodules, whereas the other 190 had thyroid malignancy. The mean body mass index (BMI) was 22.2 ± 3.7 kg/m² (range: 15.9–37.0 kg/m²). All of the operations were performed successfully without any open conversions, and patients were discharged on postoperative day 3 or 4 without significant complication. The mean operative time for thyroid lobectomy with the two-step retraction method was 116.69 ± 23.23 min, which was similar to that in the conventional robotic skin flap method (115.33 ± 17.29 min). We could minimize the extent of the robotic skin flap dissection with the two-step retraction method.

Conclusions

START is a practical surgical method. By employing the new two-step retraction method, we can maximize the cosmetic and functional benefits for patients and reduce the workload fatigue of surgeons by increasing robotic dependency.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08837-9.

A Scoping Review of the Methodology Used in Studies of Genetic Influences on the Development of Keloid or Hypertrophic Scarring in Adults and Children After Acute Wounding

Significance: Keloid and hypertrophic scarring are common following acute wounds. However, the variability in scarring outcomes between individuals and in particular, the association between genetic factors and scarring, is not well understood. This scoping review aims to summarize the methodology used in studies of genetic influences on the development of keloid or hypertrophic scarring in adults and children after acute wounding. The objectives were to determine the study designs used, the characteristics of participants included, the tools used to assess scarring and the length of follow-up after wounding.

Recent Advances: The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Excerpta Medica Database (EMBASE), Web of Science, Biosciences Information Service (BIOSIS), Prospective Register of Systematic Reviews (PROSPERO), The Human Genetic Epidemiology (HuGE) Navigator (database of genetic association studies), and the genome-wide association study Catalog were searched from January 2008 to April 2020. Cohort studies and case–control studies that examined the association between one or more genetic variations and the development of keloid or hypertrophic scarring were eligible for inclusion. A narrative synthesis that grouped studies by wound type was conducted.

Critical Issues: Nine studies met the inclusion criteria (five in burns, four surgical wounds, and none in other types of acute wounds). Seven assessed hypertrophic scarring, one keloid scarring, and one both scar types. Seven studies used a prospective cohort design. All studies used subjective methods (clinician or patient observation) to assess scarring. There was considerable variation in how scar scales were operationalized.

Future Directions: This review identified a small body of evidence on genetic susceptibility to scarring after acute wounding. Further studies are needed, and in a wide range of populations, including patients with wounds caused by trauma.

Silicone gel sheeting for treating hypertrophic scars

BACKGROUND

Each year, in high-income countries alone, approximately 100 million people develop scars. Excessive scarring can cause pruritus, pain, contractures, and cosmetic disfigurement, and can dramatically affect people's quality of life, both physically and psychologically. Hypertrophic scars are visible and elevated scars that do not spread into surrounding tissues and that often regress spontaneously. Silicone gel sheeting (SGS) is made from medical-grade silicone reinforced with a silicone membrane backing and is one of the most commonly used treatments for hypertrophic scars.

OBJECTIVES

To assess the effects of silicone gel sheeting for the treatment of hypertrophic scars in any care setting.

SEARCH METHODS

In April 2021 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled people with any hypertrophic scars and assessed the use of SGS.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, data extraction and GRADE assessment of the certainty of evidence. We resolved initial disagreements by discussion, or by consulting a third review author when necessary.

MAIN RESULTS

Thirteen studies met the inclusion criteria. Study sample sizes ranged from 10 to 60 participants. The trials were clinically heterogeneous with differences in duration of follow-up, and scar site. We report 10 comparisons, SGS compared with no SGS treatment and SGS compared with the following treatments: pressure garments; silicone gel; topical onion extract; polyurethane; propylene glycol and hydroxyethyl cellulose sheeting; Kenalog injection; flashlamp-pumped pulsed-dye laser; intense pulsed light  and Gecko Nanoplast (a silicone gel bandage). Six trials had a split-site design and three trials had an unclear design (resulting in a mix of paired and clustered data). Included studies reported limited outcome data for the primary review outcomes of severity of scarring measured by health professionals and adverse events (limited data reported by some included studies, but further analyses of these data was not possible) and no data were reported for severity of scarring reported by patients. For secondary outcomes some pain data were reported, but health-related quality of life and cost effectiveness were not reported. Many trials had poorly-reported methodology, meaning the risk of bias was unclear. We rated all evidence as being either of low or very low certainty, often because of imprecision resulting from few participants, low event rates, or both, all in single studies. SGS compared with no SGS Seven studies with 177 participants compared SGS with no SGS for hypertrophic scars. Two studies with 31 participants (32 scars) reported severity of scarring assessed by health professionals, and it is uncertain whether there is a difference in severity of scarring between the two groups (mean difference (MD) -1.83, 95% confidence interval (CI) -3.77 to 0.12; very low-certainty evidence, downgraded once for risk of bias, and twice for serious imprecision). One study with 34 participants suggests SGS may result in a slight reduction in pain level compared with no SGS treatment (MD -1.26, 95% CI -2.26 to -0.26; low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with pressure garments One study with 54 participants was included in this comparison. The study reported that SGS may reduce pain levels compared with pressure garments (MD -1.90, 95% CI -2.99 to -0.81;  low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with silicone gel One study with 32 participants was included in this comparison. It is unclear if SGS impacts on severity of scarring assessed by health professionals compared with silicone gel (MD 0.40, 95% CI -0.88 to 1.68; very low-certainty evidence, downgraded once for risk of bias, twice for imprecision). SGS compared with topical onion extract One trial (32 participants) was included in this comparison. SGS may slightly reduce severity of scarring compared with topical onion extract (MD -1.30, 95% CI -2.58 to -0.02; low-certainty evidence, downgraded once for risk of bias, and once for imprecision). SGS compared with polyurethane One study with 60 participants was included in this comparison. It is unclear if SGS impacts on the severity of scarring assessed by health professionals compared with polyurethane (MD 0.50, 95% CI -2.96 to 3.96; very low-certainty evidence, downgraded once for risk of bias, and twice for imprecision). SGS compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting One study with 38 participants was included in this comparison. It is uncertain if SGS reduces pain compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting (MD -0.12, 95% CI -0.18 to -0.06). This is very low-certainty evidence, downgraded once for risk of bias, once for imprecision and once for indirectness. SGS compared with Gecko Nanoplast One study with 60 participants was included in this comparison. It is unclear if SGS impacts on pain compared with Gecko Nanoplast (MD 0.70, 95% CI  -0.28 to 1.68; very low-certainty evidence, downgraded once for risk of bias and twice for imprecision. There was a lack of reportable data from the other three comparisons of SGS with Kenalog injection, flashlamp-pumped pulsed-dye laser or intense pulsed light.

AUTHORS' CONCLUSIONS

There is currently limited rigorous RCT evidence available about the clinical effectiveness of SGS in the treatment of hypertrophic scars. None of the included studies provided evidence on severity of scarring validated by participants, health-related quality of life, or cost effectiveness. Reporting was poor, to the extent that we are not confident that most trials are free from risk of bias. The limitations in current RCT evidence suggest that further trials are required to reduce uncertainty around decision-making in the use of SGS to treat hypertrophic scars.

The effects of kiwifruit dressing on hypertrophic scars in a rabbit ear model

AIMS

Hypertrophic scars show abnormal responses during healing. These scars, associated with dysregulated growth and excessive collagen formation, can have both functional and cosmetic consequences for patients. The present study evaluated the effects of kiwifruit on hypertrophic scars in a rabbit ear model.

METHODS

This study included 13 New Zealand albino rabbits with full thickness wounds down to the cartilage (four wounds per ear; total: 104 scars). Sixteen days after initial wound formation, one ear of each rabbit was treated with daily kiwifruit dressing, while the other ear (control group) was dressed after normal saline irrigation for 10 days. Harvested skin samples were examined for histopathological, morphometric and immunohistochemical results.

RESULTS

In comparison with the control group, early kiwifruit dressing significantly reduced the scar elevation index, fibroblast count and dermal collagen organisation. The ratio of collagen type III to total collagen immunoreactivity, inflammation and dermal capillary count increased significantly in the treated group, compared to the untreated controls.

CONCLUSION

Based on the findings, early kiwifruit dressing improved the histological features of cutaneous wounds in rabbits. Therefore, this approach may be effective in clinical practice.

Efficacy and safety of laser combination therapy and laser alone therapy for keloid: a systematic review and meta-analysis

To evaluate the efficacy and safety of laser alone therapy and laser combination therapy (mainly combined with other kinds of laser or steroids) for keloid.PubMed, Embase and Web of Science were searched for relevant articles from inception to June 2020. Comprehensive Meta-Analysis software 2.0 (CMA) was used to perform the meta-analysis.A total of 29 articles were included in this meta-analysis. During the mean follow-up of 14 (1-84) months, the overall improvement rates of baseline Vancouver scar scale (VSS) score and itch were 0.454 (95%CI 0.351-0.561, I² = 0) and 0.786 (95%CI 0.613-0.895, I² = 0) in the laser combination therapy group. The improvement rates of scar height and flexibility in the laser combination therapy group were 0.629 (95%CI 0.519-0.727, I² = 52.089) and 0.784 (95%CI 0.251-0.975, I² = 89.420). The average improvement rate of the scar score in laser combination therapy was 0.338 (0.201-0.510); however, there were insufficient data for laser alone therapy comparison. The laser combination therapy had a greater pain improvement rate, 0.580 (0.389-0.750) versus 0.420 (0.224-0.645), compared to laser alone therapy, and a greater degree of good or excellent (> 50%) improvement in the overall scar, 0.636 (95%CI 0.347-0.852) versus 0.149 (95%CI 0.032-0.482), with laser alone therapy. Moreover, a lower regrowth rate of 0.187 (0.129-0.263) versus 0.249 (0.060-0.631), a lower post-treatment pigmentation rate of 0.125 (0.091-0.169) versus 0.135 (0.058-0.282), and a lower infection rate of 0.047 (0.009-0.209) versus 0.076 (0.012-0.351) were observed in the laser combination therapy compared with those rates in the laser alone therapy.The overall effect of laser combination therapy was better than that of laser alone therapy, and the incidence of adverse reactions was lower in laser combination therapy than in laser alone therapy.

Treatment of keloids and hypertrophic scars. Position statement of the Brazilian expert group GREMCIQ

Keloids (K) and hypertrophic scars (HS) are abnormal responses to wound healing that occur as the result of dermal inflammation. Despite the advances on their treatment, many patients still suffer from the negative effects of excessive scarring; its approach is impaired by the lack of objective data on different treatments and the large genetic variability among patients and the difficulties in producing multicentre studies. Their incidence among the Brazilian population is high, as the result of an admixture of Amerindians, Europeans and Africans ancestral roots. With the aim of producing multicentre studies on K and HS, a panel of senior Brazilian dermatologists focused on their treatment was invited to contribute with the K and HS Treatment Brazilian Guidelines. In the first part of this study, different treatment modalities for keloids and HS are fully reviewed by the panel. The second part of the study presents a consensus recommendation of treatment for different types of lesions. More than a literature review, this article aims to show the pitfalls and pearls of each therapeutic option, as well as a therapeutic approach by the Panel of Experts on keloids and Scars on a highly mixed population, providing simple guidelines.

Targeting cannabinoid receptor 2 (CB2) limits collagen production-An in vitro study in a primary culture of human fibroblasts

Previous studies showed that cannabinoid 2 (CB2) receptor is involved in skin inflammation, fibrogenesis and re-epithelialization in mice, indicating that this receptor may be implicated in wound healing. Thus, topical use of cannabinoids may have a role in local fibrotic and wound healing diseases such as scars or keloids. We investigate the effect of the CB2 selective receptor agonist (6aR,10aR)-3-(1,1-Dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran (JWH133) and the CB2 selective receptor antagonist (6-Iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl)(4-methoxyphenyl)-methanone (AM630), on primary cultures of human fibroblasts. Primary cultures of adult human fibroblasts were obtained from abdominal human skin samples. Fibroblasts pretreated with JWH133 and/or AM630 were stimulated with TGF-β (10 ng/ml). Fibroblast activation into myofibroblasts was quantified by the expression of alpha-smooth muscle actin (α-SMA) using Immunocytochemistry and Western Blot assays. Collagen content was quantified with the Sirius red staining assay. Upon human fibroblasts stimulation with TGF-β, a significant increase on α-SMA and CB2 receptor expression was observed. In these cells, JWH133 decreased α-SMA expression and collagen content. However, this effect was not observed in resting human fibroblasts. AM630 decreased α-SMA expression and collagen content in both resting and activated fibroblasts. This effect was time- and concentration-dependent with an IC₅₀ value of 11 μM. The CB2 receptor appears to be involved in fibroblast repair during skin wound healing in humans, as TGF-β increases CB2 receptor expression and JWH133 produces an anti-fibrotic effect in human fibroblasts. AM630 also showed an anti-fibrotic effect hypothesizing that other cannabinoid receptors, such as TRPV, may be involved in this response.

Exosomale microRNA-21 Promotes Keloid Fibroblast Proliferation and Collagen Production by inhibiting Smad7

In keloid fibroblasts, microRNA-21 (miR-21) enhances activation of the TGF-β-Smad-signaling pathway by downregulating Smad7 expression, thereby promoting keloid fibroblast proliferation and collagen production. However, it is unclear whether miR-21 performs the above-mentioned functions through exosomal transport. Here, we extracted exosomes from the culture supernatants of keloid and normal skin fibroblasts, and observed that exosomes from both cell types secreted exosomes; however, keloid fibroblasts secreted significantly more exosomal miR-21 than normal skin fibroblasts (P < 0.001). Interestingly, we also observed that exosomal miR-21 could enter target keloid fibroblasts. In addition, inhibiting exosomal miR-21 upregulated Smad7 protein expression and reduced Smad2 and Smad3 protein levels in target keloid fibroblasts. Furthermore, inhibiting exosomal miR-21 downregulated collagen I and collagen III expression in target keloid fibroblasts, increased the proportion of apoptotic cells, and reduced cell proliferation. Taken together, these results show that exosomal miR-21 promoted proliferation and collagen production in keloid fibroblasts by inhibiting Smad7. Thus, we identified regulatory roles for miR-21 in promoting keloid fibroblast proliferation and participating in keloid formation and development. These findings imply that miR-21 may serve as a novel target for controlling the development of keloids.

Wound Healing Activity of Opuntia ficus-indica Fixed Oil Formulated in a Self-Nanoemulsifying Formulation

INTRODUCTION

Delayed wound healing represents a common health hazard. Traditional herbal products have been often utilized to promote wound contraction. The current study aimed at assessing the wound healing activity of Opuntia ficus-indica seed oil (OFI) and its self-nanoemulsifying drug delivery system (OFI-SNEDDS) formula in a rat model of full-thickness skin excision.

METHODS

Based on droplet size, an optimized OFI-SNEDDS formula was prepared and used for subsequent evaluation. Wound healing activity of OFI and OFI-SNEDDS was studied in vivo.

RESULTS

The optimized OFI-SNEDDS formula droplet size was 50.02 nm. The formula exhibited superior healing activities as compared to regular OFI seed oil-treated rats at day 14 of wounding. This effect was further confirmed by histopathological examinations of H&E and Masson's Trichrome-stained skin sections. Moreover, OFI-SNEDDS showed the highest antioxidant and anti-inflammatory activities as compared to OFI seed oil-treated animals. Both OFI and OFI-SNEDDS significantly enhanced hydroxyproline skin content and upregulated Col1A1 mRNA expression, accompanied by enhanced expression of transforming factor-beta (TGF-β). Further, OFI-SNEDDS improved angiogenesis as evidenced by increased expression of vascular endothelial growth factor (VEGF).

CONCLUSION

OFI possesses wound healing properties that are enhanced by self-emulsification of the oil into nano-droplets. The observed activity can be attributed, at least partly, to its anti-inflammatory, pro-collagen and angiogenic properties.

Triple treatment in ear keloids: Comparison of post-excisional intralesional steroid and platelet-rich plasma treatment

PURPOSE

Ear keloids lead to psychological problems in the patient by causing complaints, such as itching and swelling. It is highly resistant to treatment, and recurrences are frequent. In the present study, the purpose was to investigate the treatment success of the intralesional steroid and PRP combination in addition to surgical excision in ear keloids. The 5-year recurrence rates and adverse effects of both treatments were also compared in this respect.

MATERIALS AND METHODS

In this study, 60 patients between the ages of 16 and 65 who were followed up between 2015 and 2020 due to ear keloids were evaluated retrospectively. Patients were divided into 3 different groups (n = 20) as (A-B-C). There were patients who had only intralesional steroid injections due to ear keloids in Group A, patients who had intraoperative/postoperative steroid injections combined with surgical excision were in Group B, and patients who had intraoperative/postoperative steroid+intraoperative Platelet-Rich Plasma (PRP) injections combined with surgical excision were in Group C.

RESULTS

It was found that the 5-year recurrence rate was the lowest in Group C (Surgical Excision+PRP + TAC). The 5-year recurrence rate of Group C was significantly lower when compared with other groups (p < 0.05). When the 5-year recurrence rate of Group A (TAC) and B (Surgical Excision+TAC) was compared, the recurrence rate of Group B was significantly lower (p < 0.05). When the adverse effects were compared, no significant differences were detected between two Groups (A-B) in terms of Skin Atrophy and Telangiectasia. Significant differences were detected between patients in Group C and other groups (p < 0.05). No significant differences were detected between Group B and C (p = 0.832).

CONCLUSION

The combination of surgical excision with Intralesional TAC and PRP treatment in patients with ear keloids should be considered as a highly successful multimodal treatment in terms of low recurrence and adverse effects.

A Prototype Skin Substitute, Made of Recycled Marine Collagen, Improves the Skin Regeneration of Sheep

Simple Summary

Marine ecosystems are a huge source of unexplored “blue” materials for different applications. The edible part of sea urchin is limited, and the vast majority of the product ends up as waste. Our studies intend to fully recycle wastes from the food industry and reconvert them in high added-value products, as innovative biocompatible skin substitutes for tissue regeneration. The aim of the present work is to apply the pioneering skin substitute in in vivo experimental wounds to test its regenerative potential and compare it, in a future study, to the available commercial membranes produced with collagen of bovine, porcine, and equine origin. Results are encouraging since the skin substitute made with marine collagen reduced inflammation, promoted the deposition of granulation tissue, and enhanced a proper re-epithelialization with the adequate development of skin appendages. In summary, our findings might be of great interest for processing industries and biotech companies which transform waste materials in high-valuable and innovative products for Veterinary advanced applications.

Abstract

Skin wound healing is a complex and dynamic process that aims to restore lesioned tissues. Collagen-based skin substitutes are a promising treatment to promote wound healing by mimicking the native skin structure. Recently, collagen from marine organisms has gained interest as a source for producing biomaterials for skin regenerative strategies. This preliminary study aimed to describe the application of a collagen-based skin-like scaffold (CBSS), manufactured with collagen extracted from sea urchin food waste, to treat experimental skin wounds in a large animal. The wound-healing process was assessed over different time points by the means of clinical, histopathological, and molecular analysis. The CBSS treatment improved wound re-epithelialization along with cell proliferation, gene expression of growth factors (VEGF-A), and development of skin adnexa throughout the healing process. Furthermore, it regulated the gene expression of collagen type I and III, thus enhancing the maturation of the granulation tissue into a mature dermis without any signs of scarring as observed in untreated wounds. The observed results (reduced inflammation, better re-epithelialization, proper development of mature dermis and skin adnexa) suggest that sea urchin-derived CBSS is a promising biomaterial for skin wound healing in a “blue biotechnologies” perspective for animals of Veterinary interest.

Could cold plasma act synergistically with allogeneic mesenchymal stem cells to improve wound skin regeneration in a large size animal model?

Skin wound healing may sometimes lead to open sores that persist for long periods and expensive hospitalization is needed. Among different kinds of therapeutic innovative approaches, mesenchymal stem cells (MSCs) and low-temperature atmospheric pressure cold plasma (ionized gas) have been recently tested to improve this regenerative process. To optimize wound healing the present study intended to combine, for the first time, these two novel approaches in a large size animal wound healing model with the aim of assessing the putative dual beneficial effects. Based on clinical, histopathological, and molecular results a synergistic action in a second intention healing wound in sheep has been observed. Experimental wounds treated with cold plasma and MSCs showed a slower but more effective healing compared to the single treatment, as observed in previous studies. The combined treatment improved the correct development of skin appendages and structural proteins of the dermis showing the potential of the dual combination as a safe and effective tool for skin regeneration in the veterinary clinical field.

Molecular Changes Underlying Hypertrophic Scarring Following Burns Involve Specific Deregulations at All Wound Healing Stages (Inflammation, Proliferation and Maturation)

Excessive connective tissue accumulation, a hallmark of hypertrophic scaring, results in progressive deterioration of the structure and function of organs. It can also be seen during tumor growth and other fibroproliferative disorders. These processes result from a wide spectrum of cross-talks between mesenchymal, epithelial and inflammatory/immune cells that have not yet been fully understood. In the present review, we aimed to describe the molecular features of fibroblasts and their interactions with immune and epithelial cells and extracellular matrix. We also compared different types of fibroblasts and their roles in skin repair and regeneration following burn injury. In summary, here we briefly review molecular changes underlying hypertrophic scarring following burns throughout all basic wound healing stages, i.e. during inflammation, proliferation and maturation.