Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies

Polysulfide nanoparticles inhibit fibroblast-to-myofibroblast transition via extracellular ROS scavenging and have potential anti-fibrotic properties

This paper is about the effects of reactive oxygen species (ROS) - and of their nanoparticle-mediated extracellular removal - in the TGF-β1-induced differentiation of fibroblasts (human dermal fibroblasts - HDFa) to more contractile myofibroblasts, and in the maintenance of this phenotype. Here, poly(propylene sulfide) (PPS) nanoparticles have been employed on 2D and 3D in vitro models, showing extremely low toxicity and undergoing negligible internalization, thereby ensuring an extracellular-only action. Firstly, PPS nanoparticles abrogated ROS-mediated downstream molecular events such as glutathione oxidation, NF-κB activation, and heme oxidase-1 (HMOX) overexpression. Secondly, PPS nanoparticles were also capable to inhibit, prevent and reverse the TGF-β1-induced upregulation of key biomechanical elements, such as ED-a fibronectin (EF-A FN) and alpha-smooth muscle actin (α-SMA), respectively markers of protomyofibroblastic and of myofibroblastic differentiation. We also confirmed that ROS alone are ineffective promoters of the myofibroblastic transition, although their presence contributes to its stabilization. Finally, the particles also countered TGF-β1-induced matrix- and tissue-level phenomena, e.g., the upregulation of collagen type 1, the development of aberrant collagen type 1/3 ratios and the contracture of HDFa 3D-seeded fibrin constructs. In short, experimental data at molecular, cellular and tissue levels show a significant potential in the use of PPS nanoparticles as anti-fibrotic agents.

Ellagic acid inhibits the formation of hypertrophic scars by suppressing TGF-β/Smad signaling pathway activity

Hypertrophic scar (HS) is a benign fibroproliferative skin disease, which lacks the ideal treatment and drugs. Ellagic acid (EA) is a natural polyphenol that prevents fibroblasts from proliferating and migrating. This study aimed to determine the role of EA in HS formation and its possible mechanism by in vitro experiments. HS fibroblasts (HSFs) and normal fibroblasts (NFs) were separated from HS tissue and normal skin tissue, respectively. HSFs were treated with 10 and 50 μM EA to assess their effect on HS formation. In particular, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and scratch assay were used to detect the viability and migration ability of HSFs. Quantitative reverse transcriptase real-time polymerase chain reaction was used to measure the mRNA expression level of basic fibroblast growth factor (bFGF), extracellular matrix (ECM)-related gene collagen-I (COL-I), and fibronectin 1 (FN1) in HSFs. Finally, Western blot was utilized to measure the expression level of TGF-β/Smad signaling pathway-related proteins in HSFs. The viability of HSFs was significantly increased compared with NFs. 10 and 50 μM EA treatment markedly inhibition the cell viability and migration of HSFs. EA treatment upregulated the bFGF expression level and downregulated the COL-I and FN1 expression level in HSFs. In addition, p-Smad2, p-Smad3, and transforming growth factor (TGF)-β1 expression levels as well as p-Smad2/Smad2 and p-Smad3/Smad3 ratios remarkably decreased in HSFs after EA treatment. EA inhibited the formation of HSs by suppressing the viability and migration of HSFs and ECM deposition as well as by preventing the activation of TGF-β/Smad signaling.

Biodegradable piezoelectric skin-wound scaffold

Electrical stimulation (ES) induces wound healing and skin regeneration. Combining ES with the tissue-engineering approach, which relies on biomaterials to construct a replacement tissue graft, could offer a self-stimulated scaffold to heal skin-wounds without using potentially toxic growth factors and exogenous cells. Unfortunately, current ES technologies are either ineffective (external stimulations) or unsafe (implanted electrical devices using toxic batteries). Hence, we propose a novel wound-healing strategy that integrates ES with tissue engineering techniques by utilizing a biodegradable self-charged piezoelectric PLLA (Poly (l-lactic acid)) nanofiber matrix. This unique, safe, and stable piezoelectric scaffold can be activated by an external ultrasound (US) to produce well-controlled surface-charges with different polarities, thus serving multiple functions to suppress bacterial growth (negative surface charge) and promote skin regeneration (positive surface charge) at the same time. We demonstrate that the scaffold activated by low intensity/low frequency US can facilitate the proliferation of fibroblast/epithelial cells, enhance expression of genes (collagen I, III, and fibronectin) typical for the wound healing process, and suppress the growth of S. aureus and P. aeruginosa bacteria in vitro simultaneously. This approach induces rapid skin regeneration in a critical-sized skin wound mouse model in vivo. The piezoelectric PLLA skin scaffold thus assumes the role of a multi-tasking, biodegradable, battery-free electrical stimulator which is important for skin-wound healing and bacterial infection prevention simultaneuosly.

Clinical utility of i-gel® and BlockBuster™ supraglottic devices for airway management in postburn injury contracture neck patients under general anesthesia: A randomized controlled trial

Background

Post burn injury contracture (PBC) neck patients pose a unique challenge for the anesthesiologists. The use of supraglottic device (SGDs) for managing such patients is being increasingly used. We compared i-gel® and LMA BlockBuster™ in PBC adult patients under general anesthesia (GA).

Methods

The study included 63 subjects with mild/moderate PBC neck of either sex with American Society of Anesthesiologists Physical Status I and II under GA. Patients with intraoral pathology, mouth opening <2.5 cm, and severe contracture were excluded. Patients were randomly assigned to i-gel® (I) and BlockBuster™ (B) groups. The primary objective of the study was the time for successful insertion. First attempt success rate, oropharyngeal leak pressures (OLP), and complications were also assessed.

Results

Mean insertion time was significantly less in Group I as compared to Group B (17.35 ± 1.43 vs. 21.32 ± 1.10 s; P < 0.001), OLP in Group B was significantly higher as compared to Group I (34.03 ± 1.33 vs. 25.23 ± 3.04 cm of H2O; P < 0.001). Group I was found to be statistically easier to insert as compared to Group B (P = 0.011) with reduced requirement of airway maneuvering to insert the device (P = 0.017). Groups were similar in terms of complications.

Conclusion

SGDs are attractive option for airway management in mild/moderate degree of PBC neck. i-gel® having shorter insertion time with easier insertion can be favorable at times of emergency while use of LMA BlockBuster™ can be preferred to reduce the risk of aspiration owing to higher OLP.

Silibinin Downregulates Types I and III Collagen Expression via Suppression of the mTOR Signaling Pathway

Keloid scars are fibro-proliferative conditions characterized by abnormal fibroblast proliferation and excessive extracellular matrix deposition. The mammalian target of the rapamycin (mTOR) pathway has emerged as a potential therapeutic target in keloid disease. Silibinin, a natural flavonoid isolated from the seeds and fruits of the milk thistle, is known to inhibit the mTOR signaling pathway in human cervical and hepatoma cancer cells. However, the mechanisms underlying this inhibitory effect are not fully understood. This in vitro study investigated the effects of silibinin on collagen expression in normal human dermal and keloid-derived fibroblasts. We evaluated the effects of silibinin on the expressions of collagen types I and III and assessed its effects on the suppression of the mTOR signaling pathway. Our findings confirmed elevated mTOR phosphorylation levels in keloid scars compared to normal tissue specimens. Silibinin treatment significantly reduced collagen I and III expressions in normal human dermal and keloid-derived fibroblasts. These effects were accompanied by the suppression of the mTOR signaling pathway. Our findings suggest the potential of silibinin as a promising therapeutic agent for preventing and treating keloid scars. Further studies are warranted to explore the clinical application of silibinin in scar management.

Therapeutic role of exosomes and conditioned medium in keloid and hypertrophic scar and possible mechanisms

Exosomes, ranging from 40 to 160 nm in diameter, are extracellular lipid bilayer microvesicles that regulate the body's physiological and pathological processes and are secreted by cells that contain proteins, nucleic acids, amino acids and other metabolites. Previous studies suggested that mesenchymal stem cell (MSC)-derived exosomes could either suppress or support keloid and hypertrophic scar progression. Although previous research has identified the potential value of MSC-exosomes in keloid and hypertrophic scar, a comprehensive analysis of different sources of MSC-exosome in keloid and hypertrophic scar is still lacking. This review mainly discusses different insights regarding the roles of MSC-exosomes in keloid and hypertrophic scar treatment and summarizes possible underlying mechanisms.

SMOOTH protocol: A pilot randomised prospective intra-patient single-blinded observational study for examining the mechanistic basis of ablative fractional carbon dioxide laser therapy in treating hypertrophic scarring

BACKGROUND

Burn injuries are the fourth most common type of trauma and are associated with substantial morbidity and mortality. The impact of burn injury is clinically significant as burn injuries often give rise to exuberant scarring. Hypertrophic scarring (HTS) is a particular concern as up to 70% of burns patients develop HTS. Laser therapy is used for treating HTS and has shown positive clinical outcomes, although the mechanisms remain unclear limiting approaches to improve its effectiveness. Emerging evidence has shown that fibroblasts and senescent cells are important modifiers of scarring. This study aims to investigate the cellular kinetics in HTS after laser therapy, with a focus on the association of scar reduction with the presence of senescent cells.

METHODS

We will conduct a multicentre, intra-patient, single-blinded, randomised controlled longitudinal pilot study with parallel assignments to achieve this objective. 60 participants will be recruited to receive 3 interventional ablative fractional CO2 laser treatments over a 12-month period. Each participant will have two scars randomly allocated to receive either laser treatment or standard care. Biopsies will be obtained from laser-treated, scarred-no treatment and non-scarred tissues for immune-histological staining to investigate the longitudinal kinetics of p16INK4A+-senescent cells and fibroblast subpopulations (CD90+/Thy1+ and αSMA+). Combined subjective scar assessments including Modified Vancouver Scar Scale, Patient and Observer Scar Assessment Scale and Brisbane Burn Scar Impact Profile; and objective assessment tools including 3D-Vectra-H1 photography, DermaScan® Cortex, Cutometer® and ColoriMeter®DSMIII will be used to evaluate clinical outcomes. These will then be used to investigate the association between senescent cells and scar reduction after laser therapy. This study will also collect blood samples to explore the systemic biomarkers associated with the response to laser therapy.

DISCUSSION

This study will provide an improved understanding of mechanisms potentially mediating scar reduction with laser treatment, which will enable better designs of laser treatment regimens for those living with HTS.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04736251.

The Dipeptide Gly-Pro (GP), Derived from Hibiscus sabdariffa, Exhibits Potent Antifibrotic Effects by Regulating the TGF-β1-ATF4-Serine/Glycine Biosynthesis Pathway

TGF-β1, a key fibrotic cytokine, enhances both the expression and translocation of the activating transcriptional factor 4 (ATF4) and activates the serine/glycine biosynthesis pathway, which is crucial for augmenting collagen production. Targeting the TGF-β1-ATF4-serine/glycine biosynthesis pathway might offer a promising therapeutic approach for fibrotic diseases. In this study, we aimed to identify a proline-containing dipeptide in Hibiscus sabdariffa plant cells that modulates collagen synthesis. We induced Hibiscus sabdariffa plant cells and screened for a proline-containing dipeptide that can suppress TGF-β1-induced collagen synthesis in fibroblasts. Analyses were conducted using LC-MS/MS, RT-qPCR, Western blot analysis, and immunocytochemistry. We identified Gly-Pro (GP) from the extract of Hibiscus sabdariffa plant cells as a dipeptide capable of suppressing TGF-β1-induced collagen production. GP inhibited the phosphorylation of Smad2/3 and reduced the expression of ATF4, which is upregulated by TGF-β1. Notably, GP also decreased the expression of enzymes involved in the serine/glycine biosynthesis and glucose metabolism pathways, such as PHGDH, PSAT1, PSPH, SHMT2, and SLC2A1. Our findings indicate that the peptide GP, derived from Hibiscus sabdariffa plant cells, exhibits potent anti-fibrotic effects, potentially through its regulation of the TGF-β1-ATF4-serine/glycine biosynthesis pathway.

Defining a Unique Gene Expression Profile in Mature and Developing Keloids

Keloids are benign, fibroproliferative dermal tumors that typically form owing to abnormal wound healing. The current standard of care is generally ineffective and does not prevent recurrence. To characterize keloid scars and better understand the mechanism of their formation, we performed transcriptomic profiling of keloid biopsies from a total of 25 subjects of diverse racial and ethnic origins, 15 of whom provided a paired nonlesional sample, a longitudinal sample, or both. The transcriptomic signature of nonlesional skin biopsies from subjects with keloids resembled that of control skin at baseline but shifted to closely match that of keloid skin after dermal trauma. Peripheral keloid skin and rebiopsied surrounding normal skin both showed upregulation of epithelial-mesenchymal transition markers, extracellular matrix organization, and collagen genes. These keloid signatures strongly overlapped those from healthy wound healing studies, usually with greater perturbations, reinforcing our understanding of keloids as dysregulated and exuberant wound healing. In addition, 219 genes uniquely regulated in keloids but not in normal injured or uninjured skin were also identified. This study provides insights into mature and developing keloid signatures that can act as a basis for further validation and target identification in the search for transformative keloid treatments.

Osteopathic Approach for Keloids and Hypertrophic Scars

The skin is a complex organ, a system that influences and is influenced by the body system, with different skin layers always mechano-biologically active. In the presence of a lesion that damages the dermis, the skin undergoes sensory, morphological, and functional alterations. The subsequent adaptation is the formation of scar tissue, following distinct and overlapping biological phases. For reasons not yet fully elucidated, some healing processes lead to pathological scars, from which symptoms such as pain, itching, and functional limitations are derived. Currently, there is no gold standard treatment that fully meets the needs of different scars and can eliminate any symptoms that the patient suffers. One such treatment is manual medicine, which involves direct manual approaches to the site of injury. Reviewing the phases that allow the skin to be remodeled following an injury, this article reflects on the usefulness of resorting to these procedures, highlighting erroneous concepts on which the manual approach is based, compared to what the current literature highlights the cicatricial processes. Considering pathological scar adaptations, it would be better to follow a gentle manual approach.

Treatment of traumatic hypertrophic scars and keloids: a systematic review of randomized control trials

Exaggerated healing and remodeling after skin injury may cause hypertrophic and keloidal scars, which are associated with functional and quality of life impairment. There is limited guidance available regarding the relative effectiveness of therapies for hypertrophic scars and keloids. In this review, we aim to compare the effectiveness of treatments for hypertrophic scars and keloids. MEDLINE, Embase, Scopus, and the Cochrane Collaboration database were searched from inception to March 2019 for randomized control trials of treatments for hypertrophic and keloid scars that included 20 or more patients. Outcomes evaluated included the standardized mean reduction in scarring and adverse events. The type of scar and the demographic features were analyzed for their effect on clinical outcome. Based on 25 included clinical trials, intralesional injection (64.1% [95% CI 60.8-67.5%]) may be more effective than physical (29.9% [95% CI 28.9-30.9%]) or topical treatments (34% [95% CI 31.8-36.8%]). Combination of 5-fluorouracil and triamcinolone (9:1 dilution) appeared superior among intralesional treatments for keloids. Ablative laser and pulsed-dye laser were the most useful laser treatments. Regression modeling showed laser treatment response was linked to Fitzpatrick skin type (p = 0.002). Adverse events were uncommon for all treatments and mostly transient. Intralesional treatments for keloid and hypertrophic scars may be the most reliable treatment option to improve pathologic scars, while laser treatment may have specific benefits for Fitzpatrick skin types I-III over types IV-VI. Management of pathological scars is an area of critical need, where appropriate treatment can have a significant impact on quality of life.

Mesoporous Composite Bioactive Compound Delivery System for Wound-Healing Processes

Currently, the treatment of wounds is still a challenge for healthcare professionals due to high complication incidences and social impacts, and the development of biocompatible and efficient medicines remains a goal. In this regard, mesoporous materials loaded with bioactive compounds from natural extracts have a high potential for wound treatment due to their nontoxicity, high loading capacity and slow drug release. MCM-41-type mesoporous material was synthesized by using sodium trisilicate as a silica source at room temperature and normal pressure. The synthesized mesoporous silica was characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), N2 absorption-desorption (BET), Dynamic Light Scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR), revealing a high surface area (BET, 1244 m2/g); pore diameter of approx. 2 nm; and a homogenous, ordered and hexagonal geometry (TEM images). Qualitative monitoring of the desorption degree of the Salvia officinalis (SO) extract, rich in ursolic acid and oleanolic acid, and Calendula officinalis (CO) extract, rich in polyphenols and flavones, was performed via the continuous recording of the UV-VIS spectra at predetermined intervals. The active ingredients in the new composite MCM-41/sage and marigold (MCM-41/SO&CO) were quantified by using HPLC-DAD and LC-MS-MS techniques. The evaluation of the biological composites' activity on the wound site was performed on two cell lines, HS27 and HaCaT, naturally involved in tissue-regeneration processes. The experimental results revealed the ability to stimulate collagen biosynthesis, the enzymatic activity of the main metalloproteinases (MMP-2 and MMP-9) involved in tissue remodeling processes and the migration rate in the wound site, thus providing insights into the re-epithelializing properties of mesoporous composites.

An Open-Label, Uncontrolled, Single-Arm Clinical Trial of Tofacitinib, an Oral JAK1 and JAK3 Kinase Inhibitor, in Chinese Patients with Keloid

BACKGROUND

The keloid treatment is still a thorny and complicated clinical problem, especially in multiple keloids induced by wound, severe burn, ethnic background or cultural behaviors, or unexplained skin healing. Mainstream treatments have limited efficacy in treating multiple keloids. As no oral treatment with painlessness and convenience is available, oral treatment strategies should be formulated.

OBJECTIVES

This study aimed to investigate the efficacy and therapeutic mechanism of oral tofacitinib in keloid patients.

METHODS

We recruited the 7 patients with keloid scars and prescribed 5 mg of tofacitinib twice a day orally with a maximum follow-up of 12 weeks. The Patient and Observer Scar Assessment Scale (POSAS), the Vancouver scar scale (VSS), ANTERA 3D camera, and the DUB Skin Scanner 75 were used to assess the characteristics of the lesion. Immunohistochemistry was performed to evaluate collagen synthesis, proliferation, and relative molecular pathways. Moreover, the effects of tofacitinib were assessed on keloid fibroblast in vitro.

RESULTS

After 12 weeks of oral tofacitinib, significant improvement in POSAS, VSS, and Dermatology Life Quality Index (DLQI) scores was observed (p < 0.05). The volume, lesion height, and dermis thickness of the keloid decreased (p < 0.05). Moreover, significant decreases in the expression of collagen I, Ki67, p-STAT 3, and p-SMAD2 were observed after 12 weeks of administration. In vitro experiments suggested that tofacitinib treatment inhibits fibroblast proliferation and collagen I synthesis via suppression of STAT3 and SMAD2 pathway.

CONCLUSION

Tofacitinib, a new candidate oral drug for keloid, could reduce keloid lesion volume by inhibiting collagen synthesis and inhibiting fibroblast proliferation, and alleviate itch and pain to obtain a better life quality.

Characterization of the skin keloid microenvironment

Keloids are a fibroproliferative skin disorder that develops in people of all ages. Keloids exhibit some cancer-like behaviors, with similar genetic and epigenetic modifications in the keloid microenvironment. The keloid microenvironment is composed of keratinocytes, fibroblasts, myofibroblasts, vascular endothelial cells, immune cells, stem cells and collagen fibers. Recent advances in the study of keloids have led to novel insights into cellular communication among components of the keloid microenvironment as well as potential therapeutic targets for treating keloids. In this review, we summarized the nature of genetic and epigenetic regulation in keloid-derived fibroblasts, epithelial-to-mesenchymal transition of keratinocytes, immune cell infiltration into keloids, the differentiation of keloid-derived stem cells, endothelial-to-mesenchymal transition of vascular endothelial cells, extracellular matrix synthesis and remodeling, and uncontrolled angiogenesis in keloids with the aim of identifying new targets for therapeutic benefit. Video Abstract.

Understanding Fibroblast Heterogeneity in Form and Function

Historically believed to be a homogeneous cell type that is often overlooked, fibroblasts are more and more understood to be heterogeneous in nature. Though the mechanisms behind how fibroblasts participate in homeostasis and pathology are just beginning to be understood, these cells are believed to be highly dynamic and play key roles in fibrosis and remodeling. Focusing primarily on fibroblasts within the skin and during wound healing, we describe the field's current understanding of fibroblast heterogeneity in form and function. From differences due to embryonic origins to anatomical variations, we explore the diverse contributions that fibroblasts have in fibrosis and plasticity. Following this, we describe molecular techniques used in the field to provide deeper insights into subpopulations of fibroblasts and their varied roles in complex processes such as wound healing. Limitations to current work are also discussed, with a focus on future directions that investigators are recommended to take in order to gain a deeper understanding of fibroblast biology and to develop potential targets for translational applications in a clinical setting.

A high-salt diet promotes hypertrophic scarring through TRPC3-mediated mitochondrial Ca2+ homeostasis dysfunction

Diet High in salt content have been associated with cardiovascular disease and chronic inflammation. We recently demonstrated that transient receptor potential canonical 3 (TRPC3) channels regulate myofibroblast transdifferentiation in hypertrophic scars. Here, we examined how high salt activation of TRPC3 participates in hypertrophic scarring during wound healing. In vitro, we confirmed that high salt increased the TRPC3 protein expression and the marker of myofibroblast alpha smooth muscle actin (α-SMA) in wild-type mice (WT) primary cultured dermal fibroblasts but not Trpc3-/- mice. Activation of TRPC3 by high salt elevated cytosolic Ca2+ influx and mitochondrial Ca2+ uptake in dermal fibroblasts in a TRPC3-dependent manner. High salt activation of TRPC3 enhanced mitochondrial respiratory dysfunction and excessive ROS production by inhibiting pyruvate dehydrogenase action, that activated ROS-triggered Ca2+ influx and the Rho kinase/MLC pathway in WT mice but not Trpc3-/- mice. In vivo, a persistent high-salt diet promoted myofibroblast transdifferentiation and collagen deposition in a TRPC3-dependent manner. Therefore, this study demonstrates that high salt enhances myofibroblast transdifferentiation and promotes hypertrophic scar formation through enhanced mitochondrial Ca2+ homeostasis, which activates the ROS-mediated pMLC/pMYPT1 pathway. TRPC3 deficiency antagonizes high salt diet-induced hypertrophic scarring. TRPC3 may be a novel target for hypertrophic scarring during wound healing.

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.

Instrumented assisted soft tissue mobilization vs extracorporeal shock wave therapy in treatment of myofascial pain syndrome

BACKGROUND

Active myofascial trigger points (TrPs) often occur in the upper region of the upper trapezius (UT) muscle. These TrPs can be a significant source of neck, shoulder, and upper back pain and headaches. These TrPs and their related pain and disability can adversely affect an individual’s everyday routine functioning, work-related productivity, and general quality of life.

AIM

To investigate the effects of instrument assisted soft tissue mobilization (IASTM) vs extracorporeal shock wave therapy (ESWT) on the TrPs of the UT muscle.

METHODS

A randomized, single-blind, comparative clinical study was conducted at the Medical Center of the Egyptian Railway Station in Cairo. Forty patients (28 females and 12 males), aged between 20-years-old and 40-years-old, with active myofascial TrPs in the UT muscle were randomly assigned to two equal groups (A and B). Group A received IASTM, while group B received ESWT. Each group was treated twice weekly for 2 weeks. Both groups received muscle energy technique for the UT muscle. Patients were evaluated twice (pre- and post-treatment) for pain intensity using the visual analogue scale and for pain pressure threshold (PPT) using a pressure algometer.

RESULTS

Comparing the pre- and post-treatment mean values for all variables for group A, there were significant differences in pain intensity for TrP1 and TrP2 (P = 0.0001) and PPT for TrP1 (P = 0.0002) and TrP2 (P = 0.0001). Also, for group B, there were significant differences between the pre- and post-treatment pain intensity for TrP1 and TrP2 and PPT for TrP1 and TrP2 (P = 0.0001). There were no significant differences between the two groups in the post-treatment mean values of pain intensity for TrP1 (P = 0.9) and TrP2 (P = 0.76) and PPT for TrP1 (P = 0.09) and for TrP2 (P = 0.91).

CONCLUSION

IASTM and ESWT are effective methods for improving pain and PPT in patients with UT muscle TrPs. There is no significant difference between either treatment method.

Excess KLHL24 Impairs Skin Wound Healing through the Degradation of Vimentin

Start codon variants in ubiquitin ligase KLHL24 lead to a gain-of-function mutant KLHL24-ΔN28, which mediates the excessive degradation of keratin 15, desmin, and keratin 14, resulting in alopecia, cardiopathy, and epidermolysis bullosa syndrome. Patients with alopecia, cardiopathy, and epidermolysis bullosa syndrome normally present atrophic scars after wounds heal, which is rare in KRT14-related epidermolysis bullosa. The mechanisms underlying the formation of atrophic scars in epidermolysis bullosa of patients with alopecia, cardiopathy, and epidermolysis bullosa syndrome remain unclear. This study showed that KLHL24-ΔN28 impaired skin wound healing by excessively degrading vimentin. Heterozygous Klhl24c.3G>T knock-in mice displayed delayed wound healing and decreased wound collagen deposition. We identified vimentin as an unreported substrate of KLHL24. KLHL24-ΔN28 mediated the excessive degradation of vimentin, which failed to maintain efficient fibroblast proliferation and activation during wound healing. Furthermore, by mediating vimentin degradation, KLHL24 can hinder myofibroblast activation, which attenuated bleomycin-induced skin fibrosis. These findings showed the function of KLHL24 in regulating tissue remodeling, atrophic scarring, and fibrosis.

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.

Isotretinoin and timing of procedural interventions: Clinical implications and practical points

BACKGROUND

For decades, the notion that elective surgeries and cutaneous procedures should be postponed for 6-12 months in patients on, or recently administered with isotretinoin, has been widely accepted. However, some recent studies showed the need for a change in this regard.

METHOD

Here, we reviewed the existing data in this regard through searching on PubMed, Google Scholar, and Scopus. All of the relevant papers published in English, until October, 2022, which we could access to their full-texts, were included.

RESULTS

We found some recommendations made by plastic surgeons, dermatologists, ENT surgeons, ophthalmologists, orthopedic surgeons, and dentists regarding the correct timing of procedural interventions in patients on, or recently administered with isotretinoin and tried to summarize them to provide a practical guide for clinicians.

CONCLUSION

Physicians may discuss with patients regarding the known risk of abnormal wound healing in the setting of systemic isotretinoin treatment and suggest that, when possible, surgical procedures be postponed until the activity of the retinoids has time to subside. It is even more important regarding patients with darker skin phototypes to follow an even more strict guideline.

The Potential Role of Exosomes in Aesthetic Plastic Surgery: A Review of Current Literature

Despite an increasing surge of exosome use throughout the aesthetic arena, a paucity of published exosome-based literature exists. Exosomes are membrane-bound extracellular vesicles derived from various cell types, exerting effects via intercellular communication and regulation of several signaling pathways. The purpose of this review was to summarize published articles elucidating mechanisms and potential applications, report available products and clinical techniques, and prompt further investigation of this emerging treatment within the plastic surgery community.

Methods

A literature review was performed using PubMed with keywords exosomes, secretomes, extracellular vesicles, plastic surgery, skin rejuvenation, scar revision, hair growth, body contouring, and breast augmentation. Publications from 2010 to 2021 were analyzed for relevance and level of evidence. A Google search identified exosome distributors, where manufacturing/procurement details, price, efficacy, and clinical indications for use were obtained by direct contact and summarized in table format.

Results

Exosomes are currently derived from bone marrow, placental, adipose, and umbilical cord tissue. Laboratory-based exosome studies demonstrate enhanced outcomes in skin rejuvenation, scar revision, hair restoration, and fat graft survival on the macro and micro levels. Clinical studies are limited to anecdotal results. Prices vary considerably from $60 to nearly $5000 based on company, source tissue, and exosome concentration. No exosome-based products are currently Food and Drug Administration-approved.

Conclusions

Administered alone or as an adjunct, current reports show promise in several areas of aesthetic plastic surgery. However, ongoing investigation is warranted to further delineate concentration, application, safety profile, and overall outcome efficacy.

Safety and efficacy of autologous skin tissue cells grafting for facial sunken or flat scars

Importance

It is necessary to determine whether safety and efficacy of autologous skin tissue cells grafting for facial sunken or flat scars.

Objective

To identify autologous skin tissue cells grafting can reduce facial sunken or flat scars.

Design setting and participants

In this retrospective cross-sectional study, a total of 128 patients with scar (exclude pathological scar patients), who were receiving autologous skin tissue cells grafting therapy from January 1, 2016, to December 31, 2019.

Interventions

Autologous skin tissue cells grafting.

Main outcomes and measures

Changes in scar severity, color changes in the scar area, infection rate and patient satisfaction.

Results

A total of 128 patients with scar (89 females [69.5%]; mean [SD] age, 30.6 [13.12] years) received autologous skin tissue cells grafting therapy. SCAR (Scar Cosmesis Assessment and Rating), with scores ranging from 0 (best possible scar) to 15 (worst possible scar). After treatment 12 months, the mean [SD] of SCAR score went down from 9.85 [1.33] to 2.67 [1.21]. No infection was observed during treatment or recovery, and the main drawback after autologous skin tissue cells grafting is that the color recovery time is longer. The patient satisfaction 6 months after treatment was 85.2%, furthermore 12 months after treatment patient satisfaction was 94.7%.

Conclusions and relevance

In this study, autologous skin tissue cells grafting was safe and effective to treat facial scars. Therefore, autologous skin tissue cells grafting may be recommended as a reliable treatment for facial scar.

Bilateral Keloid Formation after Otoplasty in the Presence of Prolonged Mask Wearing

Prominent ears are the most frequently observed congenital deformity of the head and neck. Various techniques have been proposed for their aesthetic correction. Typically, surgical treatment for protruding ears involves a combination of suture, cutting, and scoring techniques. Herein, we present the clinical case of an 11-year-old child who developed bilateral keloid formations 12 months after otoplasty. Keloids and hypertrophic scars can result from extensive retroauricular skin excisions that do not allow for tension-free wound closure. In addition, skin tension and friction on immature surgical scars are common risk factors for keloid formation. To comply with school guidelines aimed at reducing the transmission of SARS-CoV-2, the patient has consistently worn FFP2 masks with ear loops positioned behind the concha. Although masks play a critical role in preventing the spread of infectious diseases, they can lead to friction in the postauricular area. In light of the presented case, it is important to examine potential cofactors that may contribute to keloid formation after otoplasty, as well as suggest a strategy to safeguard the retroauricular scar.

Exploring the Potential of Ultrasound Therapy to Reduce Skin Scars: An In Vitro Study Using a Multi-Well Device Based on Printable Piezoelectric Transducers

Excessive skin scarring affects over 100 million patients worldwide, with effects ranging from cosmetic to systemic problems, and an effective treatment is yet to be found. Ultrasound-based therapies have been used to treat a variety of skin disorders, but the exact mechanisms behind the observed effects are still unclear. The aim of this work was to demonstrate the potential of ultrasound for the treatment of abnormal scarring by developing a multi-well device based on printable piezoelectric material (PiezoPaint™). First, compatibility with cell cultures was evaluated using measurements of heat shock response and cell viability. Second, the multi-well device was used to treat human fibroblasts with ultrasound and quantify their proliferation, focal adhesions, and extracellular matrix (ECM) production. Ultrasound caused a significant reduction in fibroblast growth and ECM deposition without changes in cell viability or adhesion. The data suggest that these effects were mediated by nonthermal mechanisms. Interestingly, the overall results suggest that ultrasound treatment would a be beneficial therapy for scar reduction. In addition, it is expected that this device will be a useful tool for mapping the effects of ultrasound treatment on cultured cells.

Immune cells and associated molecular markers in dermal fibrosis with focus on raised cutaneous scars

Raised dermal scars including hypertrophic, and keloid scars as well as scalp-associated fibrosing Folliculitis Keloidalis Nuchae (FKN) are a group of fibrotic raised dermal lesions that mostly occur following cutaneous injury. They are characterized by increased extracellular matrix (ECM) deposition, primarily excessive collagen type 1 production by hyperproliferative fibroblasts. The extent of ECM deposition is thought to be proportional to the severity of local skin inflammation leading to excessive fibrosis of the dermis. Due to a lack of suitable study models, therapy for raised dermal scars remains ill-defined. Immune cells and their associated markers have been strongly associated with dermal fibrosis. Therefore, modulation of the immune system and use of anti-inflammatory cytokines are of potential interest in the management of dermal fibrosis. In this review, we will discuss the importance of immune factors in the pathogenesis of raised dermal scarring. The aim here is to provide an up-to-date comprehensive review of the literature, from PubMed, Scopus, and other relevant search engines in order to describe the known immunological factors associated with raised dermal scarring. The importance of immune cells including mast cells, macrophages, lymphocytes, and relevant molecules such as cytokines, chemokines, and growth factors, antibodies, transcription factors, and other immune-associated molecules as well as tissue lymphoid aggregates identified within raised dermal scars will be presented. A growing body of evidence points to a shift from proinflammatory Th1 response to regulatory/anti-inflammatory Th2 response being associated with the development of fibrogenesis in raised dermal scarring. In summary, a better understanding of immune cells and associated molecular markers in dermal fibrosis will likely enable future development of potential immune-modulated therapeutic, diagnostic, and theranostic targets in raised dermal scarring.

Surgical Core Excision With Tongue Flap Closure in Combination With Electron Beam Radiotherapy in the Treatment of Ear Keloids

BACKGROUND

Ear keloids are disfiguring disorders resistant to various treatments.

OBJECTIVE

The authors aimed to assess the efficacy of surgical treatment of ear keloids in a Chinese population using a tongue flap with electron beam radiotherapy.

METHODS

The authors conducted a retrospective analysis of 41 patients treated at the Affiliated Hospital of Nantong University between January 2018 and May 2021. Core excision with a tongue flap was performed, followed by 3 days of electron beam radiotherapy and 3 to 6 months of pressure clip application. The Vancouver Scar Scale (VSS) and the Visual Analog Scale (VAS) were used to assess the results.

RESULTS

The mean age of the patients was 28.10 years (9-61 years). Postoperative follow-up ranged from 5 to 32 months (mean:12.07). The patients underwent 3 days of postoperative radiotherapy followed by pressure clips for 2 to 6 months. Thirty-seven patients had no recurrence, whereas 4 had a mild recurrence (<3 mm in height) with redness and itchiness. The VSS and VASscores significantly decreased. (p < .05).

CONCLUSION

Excision with a tongue flap and radiotherapy can be used as the primary treatment for ear keloids considering the good outcome and long-term management.

Current Research of Botulinum Toxin Type A in Prevention and Treatment on Pathological Scars

BACKGROUND

Dermatologists have been looking for ways to improve wound healing and postoperative scar appearance. The safety and efficacy of botulinum toxin type A (BTXA) in the prevention and treatment on pathological scars have become the current research hotspot since it was approved by the US FDA in medical cosmetology in 2002.

PURPOSE

This article aims to provide an overview of the clinical research, limitations, and application prospects of BTXA in the prevention and treatment of traumatic or postoperative pathological scars, which can provide a reference and better understanding of relevant studies.

METHODS

The current research progress was summarized and discussed, with new problems and research ideas being proposed ranging from the molecular mechanism of BTXA in preventing and treating pathological scars to its clinical application via investigation and reference research.

RESULTS

BTXA is effective in relieving itching and pain associated with pathological scars, limiting scar hyperplasia along with preventing scar contracture, but the specific mechanism is still not clear.

CONCLUSION

Most of the clinicians have confirmed the clinical effectiveness of BTXA in the prevention and treatment of pathological scars, yet its mode of action and combination therapy need more research.

Global research status of pathological scar reported over the period 2001-2021: A 20-year bibliometric analysis

Pathological scar is a classic problem in plastic and reconstructive surgery. Although the researches on pathological scar have been conducted for decades, the way to go to address this thorny problem still remains challenging. To the best of our knowledge, few bibliometric analysis concerning pathological scar have been reported. In this study, we set out to employ bibliometric and visual analysis to offer research status and trends of pathological scar over the period 2001-2021. All publications covering pathological scar during 2001-2021 were retrieved and extracted from the Web of Science database. We applied VOSviewer software to evaluate the keywords and research hotpots, and the online tool (http://bibliometric.com/) was used to carried out the publication trends analysis. A total of 2221 pathological scar-related articles were identified over the period 2001-2021. China is the country which had the largest volume of publications (819, 36.87%), followed by the United States (416, 18.73%), Japan (144, 6.48%), Korea (142, 6.39%), and England (118, 5.31%). Among the institutions and journals, Shanghai Jiao Tong University (167) and Wound Repair and Regeneration (85) accounted for the most papers related to pathological scar, respectively. Professor Bayat A, who had the most citation frequency (2303), made great contribution in pathological scar field. "Fibroblast", "expression", and "proliferation" were identified as the pathological scar research hotspot through analysis of the keywords. In terms of publication, China ranked first all over the world, but the numbers of publication are inconsistent with the citation frequency, ranking first and second, respectively. Shanghai Jiao Tong University and journal Wound Repair and Regeneration stand for the highest level of research in this field to a certain extent. In the early stage, the research focus was mainly on the prevention, treatment, and risk factors for recurrence of pathological scar from cases. In the later stage, the research focus was on the comprehensive management, in which the mechanism research was in-depth to the molecular and gene level.

The Clinical Efficacy of Punch Excision Combined With Intralesional Steroid Injection for Keloid Treatment

BACKGROUND

Conservative and nonconservative treatments are available for keloids. However, few studies have explored the effectiveness of punch excision in keloid treatment.

OBJECTIVE

This study aimed to investigate the efficacy and safety of punch excision combined with intralesional steroid injection for keloid treatment.

METHODS

In this prospective, randomized, controlled trial, 81 patients were randomly divided into 2 groups. The patients in the treatment group were initially treated with punch excision combined with intralesional steroid injection, followed by injection treatment alone. The patients in the control group received intralesional steroid injection alone. The keloid thickness before and after the punch excision was evaluated; the keloid scores at different time points and the number of injection treatments required in both groups were compared, and adverse reactions were observed.

RESULTS

The mean thickness after punch excision was lower (p < .05), injection treatments were fewer (p < .05), keloid scores were significantly lower (p < .05), and incidence rate of long-term adverse effects was lower in the treatment group than in the control group (p < .05).

CONCLUSION

The combination of punch excision and intralesional steroid injection has a notable therapeutic effect on keloids, shortening the treatment course without evident adverse reactions.

Mapping variation of extracellular matrix in human keloid scar by label-free multiphoton imaging and machine learning

Significance

Rapid diagnosis and analysis of human keloid scar tissues in an automated manner are essential for understanding pathogenesis and formulating treatment solutions.

Aim

Our aim is to resolve the features of the extracellular matrix in human keloid scar tissues automatically for accurate diagnosis with the aid of machine learning.

Approach

Multiphoton microscopy was utilized to acquire images of collagen and elastin fibers. Morphological features, histogram, and gray-level co-occurrence matrix-based texture features were obtained to produce a total of 28 features. The minimum redundancy maximum relevancy feature selection approach was implemented to rank these features and establish feature subsets, each of which was employed to build a machine learning model through the tree-based pipeline optimization tool (TPOT).

Results

The feature importance ranking was obtained, and 28 feature subsets were acquired by incremental feature selection. The subset with the top 23 features was identified as the most accurate. Then stochastic gradient descent classifier optimized by the TPOT was generated with an accuracy of 96.15% in classifying normal, scar, and adjacent tissues. The area under curve of the classification results (scar versus normal and adjacent, normal versus scar and adjacent, and adjacent versus normal and scar) was 1.0, 1.0, and 0.99, respectively.

Conclusions

The proposed approach has great potential for future dermatological clinical diagnosis and analysis and holds promise for the development of computer-aided systems to assist dermatologists in diagnosis and 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.

Recent advances in decellularized biomaterials for wound healing

The skin is one of the most essential organs in the human body, interacting with the external environment and shielding the body from diseases and excessive water loss. Thus, the loss of the integrity of large portions of the skin due to injury and illness may lead to significant disabilities and even death. Decellularized biomaterials derived from the extracellular matrix of tissues and organs are natural biomaterials with large quantities of bioactive macromolecules and peptides, which possess excellent physical structures and sophisticated biomolecules, and thus, promote wound healing and skin regeneration. Here, we highlighted the applications of decellularized materials in wound repair. First, the wound-healing process was reviewed. Second, we elucidated the mechanisms of several extracellular matrix constitutes in facilitating wound healing. Third, the major categories of decellularized materials in the treatment of cutaneous wounds in numerous preclinical models and over decades of clinical practice were elaborated. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues for research on decellularized biomaterials-based wound treatment.

The Secretome of Irradiated Peripheral Mononuclear Cells Attenuates Hypertrophic Skin Scarring

Hypertrophic scars can cause pain, movement restrictions, and reduction in the quality of life. Despite numerous options to treat hypertrophic scarring, efficient therapies are still scarce, and cellular mechanisms are not well understood. Factors secreted by peripheral blood mononuclear cells (PBMCsec) have been previously described for their beneficial effects on tissue regeneration. In this study, we investigated the effects of PBMCsec on skin scarring in mouse models and human scar explant cultures at single-cell resolution (scRNAseq). Mouse wounds and scars, and human mature scars were treated with PBMCsec intradermally and topically. The topical and intradermal application of PBMCsec regulated the expression of various genes involved in pro-fibrotic processes and tissue remodeling. We identified elastin as a common linchpin of anti-fibrotic action in both mouse and human scars. In vitro, we found that PBMCsec prevents TGFβ-mediated myofibroblast differentiation and attenuates abundant elastin expression with non-canonical signaling inhibition. Furthermore, the TGFβ-induced breakdown of elastic fibers was strongly inhibited by the addition of PBMCsec. In conclusion, we conducted an extensive study with multiple experimental approaches and ample scRNAseq data demonstrating the anti-fibrotic effect of PBMCsec on cutaneous scars in mouse and human experimental settings. These findings point at PBMCsec as a novel therapeutic option to treat skin scarring.

Effect of Hypertrophic Scar Fibroblast-Derived Exosomes on Keratinocytes of Normal Human Skin

Epidermal keratinocytes are highly activated, hyper-proliferated, and abnormally differentiated in the post-burn hypertrophic scar (HTS); however, the effects of scar fibroblasts (SFs) on keratinocytes through cell-cell interaction in HTS remain unknown. Here, we investigated the effects of HTSF-derived exosomes on the proliferation and differentiation of normal human keratinocytes (NHKs) compared with normal fibroblasts (NFs) and their possible mechanism to provide a reference for clinical intervention of HTS. Fibroblasts were isolated and cultured from HTS and normal skin. Both HTSF-exosomes and NF-exosomes were extracted via a column-based method from the cell culture supernatant. NHKs were treated for 24 or 48 h with 100 μg/mL of cell-derived exosomes. The expression of proliferation markers (Ki-67 and keratin 14), activation markers (keratins 6, 16, and 17), differentiation markers (keratins 1 and 10), apoptosis factors (Bax, Bcl2, caspase 14, and ASK1), proliferation/differentiation regulators (p21 and p27), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, and vimentin) was investigated. Compared with NF-exosomes, HTSF-exosomes altered the molecular pattern of proliferation, activation, differentiation, and apoptosis, proliferation/differentiation regulators of NHKs, and EMT markers differently. In conclusion, our findings indicate that HTSF-derived exosomes may play a role in the epidermal pathological development of HTS.

Can we suppress excessive post-surgical scar formation: A case report

BACKGROUND

Hypertrophic scars (HSs) formation is a complication that occurs after wounds heal with secondary intention and sometimes after clean surgical incisions. Many treatments are in vogue now with varying successes. Although the mechanism or mechanisms that cause a HS to form are not clearly understood, one thing that is clear is that once scar tissue matures, any intervention will not be successful. In this paper, we report on a case where a patient who was known to develop HS was treated with a new combination of ingredients (Phyto-chemicals + Silicone JUMI) to suppress HS formation.

CASE SUMMARY

A 68-year-old female of African descent presented a severe HS post total knee replacement (TKR), which the patient describes as itchy and painful. Due to complications caused by the scar, she was apprehensive about undergoing TKR on her other knee. However, after the TKR of the contralateral side post-removal of skin clips, JUMI anti-scar cream (JASC) was used to suppress excessive scar formation.

CONCLUSION

JASC appears potent and efficacious at suppressing excessive scar formation. We believe that this warrants further studies on larger patient groups and on different surgical sites.

A review on the synthesis and development of alginate hydrogels for wound therapy

Convenient and low-cost dressings can reduce the difficulty of wound treatment. Alginate gel dressings have the advantages of low cost and safe usage, and they have obvious potential for development in biomedical materials. Alginate gel dressings are currently a research area of great interest owing to their versatility, intelligent, and their application attempts in treating complex wounds. We present a detailed summary of the preparation of alginate hydrogels and a study of their performance improvement. Herein, we summarize the various applications of alginate hydrogels. The research focuses in this area mainly include designing multifunctional dressings for the treatment of various wounds and fabricating specialized dressings to assist physicians in the treatment of complex wounds (TOC). This review gives an outlook for future directions in the field of alginate hydrogel dressings. We hope to attract more research interest and studies in alginate hydrogel dressings, thus contributing to the creation of low-cost and highly effective wound treatment materials.

Engineered multi-functional, pro-angiogenic collagen-based scaffolds loaded with endothelial cells promote large deep burn wound healing

The lack of vascularization associated with deep burns delays the construction of wound beds, increases the risks of infection, and leads to the formation of hypertrophic scars or disfigurement. To address this challenge, we have fabricated a multi-functional pro-angiogenic molecule by grafting integrin αvβ3 ligand LXW7 and collagen-binding peptide (SILY) to a dermatan sulfate (DS) glycosaminoglycan backbone, named LXW7-DS-SILY (LDS), and further employed this to functionalize collagen-based Integra scaffolds. Using a large deep burn wound model in C57/BLK6 mice (8-10 weeks old, 26-32g, n = 39), we demonstrated that LDS-modified collagen-based Integra scaffolds loaded with endothelial cells (ECs) accelerate wound healing rate, re-epithelialization, vascularization, and collagen deposition. Specifically, a 2 cm × 3 cm full-thickness skin burn wound was created 48 h after the burn, and then wounds were treated with four groups of different dressing scaffolds, including Integra + ECs, Integra + LDS, and Integra + LDS + ECs with Integra-only as the control. Digital photos were taken for wound healing measurement on post-treatment days 1, 7, 14, 21, 28, and 35. Post-treatment photos revealed that treatment with the Intgera + LDS + ECs scaffold exhibited a higher wound healing rate in the proliferation phase. Histology results showed significantly increased re-epithelialization, increased collagen deposition, increased thin and mixed collagen fiber content, increased angiogenesis, and shorter wound length within the Integra + LDS + ECs group at Day 35. On Day 14, the Integra + LDS + ECs group showed the same trend. The relative proportions of collagen changed from Day 14 to Day 35 in the Integra + LDS + ECs and Integra + ECs groups demonstrated decreased thick collagen fiber deposition and greater thin and mixed collagen fiber deposition. LDS-modified Integra scaffolds represent a promising novel treatment to accelerate deep burn wound healing, thereby potentially reducing the morbidity associated with open burn wounds. These scaffolds can also potentially reduce the need for autografting and morbidity in patients with already limited areas of harvestable skin.

Long Non-Coding RNA uc003jox.1 Promotes Keloid Fibroblast Proliferation and Invasion Through Activating the PI3K/AKT Signaling Pathway

The pathogenesis of keloids is complex and unclear, and the treatment of this condition remains challenging. The long non-coding RNA uc003jox.1 is highly expressed in keloid tissues compared with in normal skin tissues. We assessed the role of uc003jox.1 in keloid fibroblasts and its underlying mechanism, focusing on the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway. Keloid fibroblasts were transfected with a small interfering RNA targeting uc003jox.1. Colony formation, transwell, and flow cytometry assays were conducted to evaluate the proliferation, invasion, and apoptosis of keloid fibroblasts, respectively. The interaction between uc003jox.1 and the PI3K/AKT pathway was explored by using polymerase chain reaction and western blotting. Knockdown of uc003jox.1 markedly suppressed keloid fibroblast proliferation, clone-forming activity, and invasion, as well as promoted apoptosis. Silencing of uc003jox.1 decreased the phosphorylation levels of PI3K, AKT, and mammalian target of rapamycin and increased both the mRNA and protein expression levels of phosphatase and tensin homolog. Our in vitro results suggest that the long non-coding RNA uc003jox.1 can be used as a biomarker for keloid fibroblasts and that its expression is closely related to the proliferation and invasion of keloid fibroblasts through the PI3K/AKT/mammalian target of rapamycin pathway. Thus, uc003jox.1 shows potential as a treatment target for keloids.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Occlusion and hydration of scars: moisturizers versus silicone gels

BACKGROUND

The mainstay of non-invasive scar management, consists of pressure therapy with customized pressure garments often combined with inlays, hydration by means of silicones and/or moisturizers as well as UV protection. It is generally accepted that scar dehydration resulting from impaired barrier function of the stratum corneum and expressed by raised trans epidermal water loss (TEWL) values, can lead to increased fibroblast activity and thereby hypertrophic scar formation. However, we have reached no consensus on exactly what optimal scar hydration is nor on barrier function repair: by means of silicone sheets, liquid silicone gels or moisturizers. Occlusive silicone sheets almost completely prevent TEWL and have been shown to be effective. Nevertheless, many important disadvantages due to excessive occlusion such as difficulties in applying the sheets exceeding 10-12 h, pruritus, irritation, and maceration of the skin are limiting factors for its use. To avoid these complications and to facilitate the application, liquid silicone gels were developed. Despite a reduced occlusion, various studies have shown that the effects are comparable to these of the silicone sheets. However, major limiting factors for general use are the long drying time, the shiny aspect after application, and the high cost especially when used for larger scars. Based on excellent clinical results after using three specific moisturizers for scar treatment in our patients, we wanted to investigate whether these moisturizers induce comparable occlusion and hydration compared to both each other and the widely recognized liquid silicone gels. We wanted to provide a more scientific basis for the kind of moisturizers that can be used as a full-fledged and cost-effective alternative to silicone gel.

METHODS

A total of 36 healthy volunteers participated in this study. Increased TEWL was created by inducing superficial abrasions by rigorous (20x) skin stripping with Corneofix® adhesive tape in squares of 4 cm². Three moisturizers and a fluid silicone gel were tested: DermaCress, Alhydran, Lipikar and BAP Scar Care silicone gel respectively. TEWL reducing capacities and both absolute (AAH) and cumulative (CAAH) absolute added hydration were assessed using a Tewameter® TM300 and a Corneometer® CM825 at different time points for up to 4 h after application.

RESULTS

We found an immediate TEWL increase in all the zones that underwent superficial abrasions by stripping. Controls remained stable over time, relative to the ambient condition. The mean percentage reduction (MPR) in TEWL kept increasing over time with Alhydran and DermaCress, reaching a maximum effect 4 h after application. Silicone gel reached maximal MPR almost immediately after application and only declined thereafter. The silicone gel never reached the minimal MPR of Alhydran or DermaCress. Hydration capacity assessed through CAAH as measured by the Corneometer was significantly less with silicone gel compared to the moisturizers. Compared to silicone gel Lipikar provided similar occlusion and the improvement in hydration was highly significant 4 h after application.

CONCLUSION

Based on the results of both our previous research and this study it is clearly demonstrated that the occlusive and hydrative effect of fluid silicone gel is inferior to the moisturizers used in our center. Lipikar hydrates well but is less suitable for scar treatment due to the lack of occlusion. A well-balanced occlusion and hydration, in this study only provided by Alhydran and DermaCress, suggests that moisturizers can be used as a scar hydration therapy that replaces silicone products, is more cost-effective and has a more patient-friendly application.

Salvianolic Acid B Attenuates Hypertrophic Scar Formation In Vivo and In Vitro

BACKGROUND

Hypertrophic scars (HTSs) are a fibroproliferative disorder that occur following skin injuries. Salvianolic acid B (Sal-B) is an extractant from Salvia miltiorrhiza that has been reported to ameliorate fibrosis in multiple organs. However, the antifibrotic effect on HTSs remains unclear. This study aimed to determine the antifibrotic effect of Sal-B in vitro and in vivo.

METHODS

In vitro, hypertrophic scar-derived fibroblasts (HSFs) were isolated from human HTSs and cultured. HSFs were treated with (0, 10, 50, 100 μmol/L) Sal-B. Cell proliferation and migration were evaluated by EdU, wound healing, and transwell assays. The protein and mRNA levels of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 were detected by Western blots and real-time PCR. In vivo, tension stretching devices were fixed on incisions for HTS formation. The induced scars were treated with 100 μL of Sal-B/PBS per day according to the concentration of the group and followed up for 7 or 14 days. The scar condition, collagen deposition, and α-SMA expression were analyzed by gross visual examination, H&E, Masson, picrosirius red staining, and immunofluorescence.

RESULTS

In vitro, Sal-B inhibited HSF proliferation, migration, and downregulated the expression of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 in HSFs. In vivo, 50 and 100 μmol/L Sal-B significantly reduced scar size in gross and cross-sectional observations, with decreased α-SMA expression and collagen deposition in the tension-induced HTS model.

CONCLUSIONS

Our study demonstrated that Sal-B inhibits HSFs proliferation, migration, fibrotic marker expression and attenuates HTS formation in a tension-induced HTS model in vivo.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Biomaterial mediated immunomodulation: An interplay of material environment interaction for ameliorating wound regeneration

Chronic wounds are the outcome of an imbalanced inflammatory response caused by sustenance of immune microenvironment. In this context, tissue engineered graft played great role in healing wounds but faced difficulty in scar remodelling, immune rejection and poor vascularization. All the limitations faced are somewhere linked with the immune cells involved in healing. In this consideration, immunomodulatory biomaterials bridge a large gap with the delivery of modulating factors for triggering key inflammatory cells responsible towards interplay in the wound micro-environment. Inherent physico-chemical properties of biomaterials substantially determine the nature of cell-materials interaction thereby facilitating differential cytokine gradient involved in activation or suppression of inflammatory signalling pathways, and followed by surface marker expression. This review aims to systematically describe the interplay of immune cells involved in different phases in the wound microenvironment and biomaterials. Additionally, it also focuses on modulating innate immune cell responses in the context of triggering the halted phase of the wound healing, i.e., inflammatory phase. The various strategies are highlighted for modulation of wound microenvironment towards wound regeneration including stem cells, cytokines, growth factors, vitamins, and anti-inflammatory agents to induce interactive ability of biomaterials with immune cells. The last section focuses on prospective approaches and current potential strategies for wound regeneration. This includes the development of different models to bridge the gap between mouse models and human patients. Emerging new tools to study inflammatory response owing to biomaterials and novel strategies for modulation of monocyte and macrophage behaviour in the wound environment are also discussed.

An Updated Review of Hypertrophic Scarring

Hypertrophic scarring (HTS) is an aberrant form of wound healing that is associated with excessive deposition of extracellular matrix and connective tissue at the site of injury. In this review article, we provide an overview of normal (acute) wound healing phases (hemostasis, inflammation, proliferation, and remodeling). We next discuss the dysregulated and/or impaired mechanisms in wound healing phases that are associated with HTS development. We next discuss the animal models of HTS and their limitations, and review the current and emerging treatments of HTS.

Dynamic characteristics of skin reaction force in different body postures

Mechanical stress influences scarring of a surgical wound. Several lines have been proposed for the best excision direction. It is unknown if these lines still apply when the body posture changes. The objective is to measure the skin reaction force in four directions and determine the direction of least force. Secondary objective is to determine if the reaction force varies in a different body posture. Skin reaction force was measured with the compressiometer in 30 participants on four different locations (forearm/upper arm/shoulder blade/lower back) in four directions (0°-45°-90°-135°) and two body postures. The direction of least skin reaction force changed with a different body posture and was significant for the forearm (p < 0.01) and shoulder blade (p = 0.05) The skin reaction force in all four direction changed significantly in a different body posture, except the 45° line in the upper arm and shoulder blade. Our results demonstrate that the skin reaction force in four directions in four locations varies with change in body posture. Focus should therefore not only lay on choosing the right direction, but also on managing skin tension postoperatively.

LEP and LEPR are possibly a double-edged sword for wound healing

Wound healing is a complex and error-prone process. Wound healing in adults often leads to the formation of scars, a type of fibrotic tissue that lacks skin appendages. Hypertrophic scars and keloids can also form when the wound-healing process goes wrong. Leptin (Lep) and leptin receptors (LepRs) have recently been shown to affect multiple stages of wound healing. This effect, however, is paradoxical for scarless wound healing. On the one hand, Lep exerts pro-inflammatory and profibrotic effects; on the other hand, Lep can regulate hair follicle growth. This paper summarises the role of Lep and LepRs on cells in different stages of wound healing, briefly introduces the process of wound healing and Lep and LepRs, and examines the possibility of promoting scarless wound healing through spatiotemporal, systemic, and local regulation of Lep levels and the binding of Lep and LepRs.

Mapping the 3D remodeling of the extracellular matrix in human hypertrophic scar by multi-parametric multiphoton imaging using endogenous contrast

The hypertrophic scar is an aberrant form of wound healing process, whose clinical efficacy is limited by a lack of understanding of its pathophysiology. Remodeling of collagen and elastin fibers in the extracellular matrix (ECM) is closely associated with scar progression. Herein, we perform label-free multiphoton microscopy (MPM) of both fiber components from human skin specimens and propose a multi-fiber metrics (MFM) analysis model for mapping the structural remodeling of the ECM in hypertrophic scars in a highly-sensitive, three-dimensional (3D) manner. We find that both fiber components become wavier and more disorganized in scar tissues, while content accumulation is observed from elastin fibers only. The 3D MFM analysis can effectively distinguish normal and scar tissues with better than 95% in accuracy and 0.999 in the area under the curve value of the receiver operating characteristic curve. Further, unique organizational features with orderly alignment of both fibers are observed in scar-normal adjacent regions, and an optimized combination of features from 3D MFM analysis enables successful identification of all the boundaries. This imaging and analysis system uncovers the 3D architecture of the ECM in hypertrophic scars and exhibits great translational potential for evaluating scars in vivo and identifying individualized treatment targets.

Mesenchymal stem cells in fibrotic diseases-the two sides of the same coin

Fibrosis is caused by extensive deposition of extracellular matrix (ECM) components, which play a crucial role in injury repair. Fibrosis attributes to ~45% of all deaths worldwide. The molecular pathology of different fibrotic diseases varies, and a number of bioactive factors are involved in the pathogenic process. Mesenchymal stem cells (MSCs) are a type of multipotent stem cells that have promising therapeutic effects in the treatment of different diseases. Current updates of fibrotic pathogenesis reveal that residential MSCs may differentiate into myofibroblasts which lead to the fibrosis development. However, preclinical and clinical trials with autologous or allogeneic MSCs infusion demonstrate that MSCs can relieve the fibrotic diseases by modulating inflammation, regenerating damaged tissues, remodeling the ECMs, and modulating the death of stressed cells after implantation. A variety of animal models were developed to study the mechanisms behind different fibrotic tissues and test the preclinical efficacy of MSC therapy in these diseases. Furthermore, MSCs have been used for treating liver cirrhosis and pulmonary fibrosis patients in several clinical trials, leading to satisfactory clinical efficacy without severe adverse events. This review discusses the two opposite roles of residential MSCs and external MSCs in fibrotic diseases, and summarizes the current perspective of therapeutic mechanism of MSCs in fibrosis, through both laboratory study and clinical trials.