Silicone-based scar therapy: a review of the literature

Prevention and Management of Complications in Nasal Reconstruction

Nasal reconstruction is a challenging practice with the potential for complications. Surgeons can prevent complications through preoperative optimization of patient factors, refinement of intraoperative surgical techniques, and postoperative surgical and nonsurgical wound care. Preoperatively, optimization of modifiable and recognition of nonmodifiable risk factors is paramount. Intraoperatively, meticulous flap design and surgical technique promote healing. In the postoperative setting, attentive wound care, adjuvant therapies, and close follow-up for consideration of additional procedures enhance outcomes. By anticipating potential complications across perioperative settings, surgeons can prevent common complications in nasal reconstruction and more effectively manage those complications that arise.

Reducing Risks of Facial Scarring

Risk factors for the formation of facial scars include skin type, ethnicity, scar location, and certain medical conditions that contribute to poor or delayed healing. Risk of scar can be reduced with appropriate surgical planning, including proper placement and design of incisions, meticulous skin closure, aseptic technique, and wound care to improve healing. Common pathologic scars include hypertrophic scars and keloid scars, each of which has unique approaches to surgical revision and medical treatment due to their respective risks of recurrence. Topical scar therapies, medical therapies, and surgical revision techniques for improvement in final scar appearance are discussed.

Silicone barrier cream in treatment of atopic dermatitis: A literature review

Atopic dermatitis (AD) is a complex skin disorder that requires multidisciplinary treatment modalities to best improve the results of the condition. Although silicone formulations have been used for the treatments of wounds, ulcers, and burns, we aim to highlight the use of a silicon solution for the treatment of eczema. Components of the silicone formula may enhance treatment for AD, such as in the wet wrap therapy, and can be a useful addition. In this report, we aim to discuss the use and properties of the wet wrap therapy with silicone and the potential benefits of applying this formula for the treatment of AD in the future.

Photobiomodulation therapy with an 830-nm light-emitting diode for the prevention of thyroidectomy scars: a randomized, double-blind, sham device-controlled clinical trial

This randomized, double-blind, and sham device-controlled trial aimed to evaluate the efficacy and safety of home-based photobiomodulation therapy using an 830-nm light-emitting diode (LED)-based device for the prevention of and pain relief from thyroidectomy scars. Participants were randomized to receive photobiomodulation therapy using an LED device or a sham device without an LED from 1 week postoperatively for 4 weeks. Scars were assessed using satisfaction scores, the numeric rating scale (NRS) score for pain, Global Assessment Scale (GAS), and Vancouver Scar Scale (VSS) scores. The scars were also assessed using a three-dimensional (3D) skin imaging device to detect color, height, pigmentation, and vascularity. Assessments were performed at the 1-, 3-, and 6-month follow-ups. Forty-three patients completed this trial with 21 patients in the treatment group and 22 patients in the control group. The treatment group showed significantly higher patient satisfaction and GAS scores and lower NRS and VSS scores than the control group at 6 months. Improvements in color variation, height, pigmentation, and vascularity at 6 months were greater in the treatment group than in the control group, although the differences were not significant. In conclusion, early application of 830-nm LED-based photobiomodulation treatment significantly prevents hypertrophic scar formation and reduces postoperative pain without noticeable adverse effects.

Poly (γ-glutamic acid)/chitooligo-saccharide/papain hydrogel prevents hypertrophic scar during skin wound healing

Hypertrophic scar, a common skin disorder typically caused by deep burns or scald were usually treated via surgical resection, laser irradiation, and drugs. However, all the approaches were always companied with complications and devastatingly subjected to relapse, which indicated the urgently need of an effective treatment method. In this project, a new hydrogel composed of Poly (γ-glutamic acid) (γ-PGA), Chitooligo-saccharide, and Papain was developed via crosslinker (EDC&NHS), and characterized with good porously three-dimensional network structure, good water absorption, and mechanical properties. Besides, G/C/P hydrogel facilitated cell adhesion and inhibited excessive proliferation of fibroblasts, which indicated the potential of in vivo application. After applied onto skin wound healing in vivo on a rabbit ear skin wound model, G/C/P hydrogel inhibited excessive collagen deposition and the generation of hyperplastic scars effectively during wound healing. The hydrogel described here provide a new platform for regeneration field and hold great promise for solving serious skin disorder.

Adding herbal extracts to silicone gel on post-sternotomy scar: a prospective randomised double-blind study

OBJECTIVE

Silicone gel has been shown effective in improving healing post-sternotomy scars. It remains to be determined whether adding herbal extracts to the gel would augment the healing effect.

METHOD

After median sternotomy, patients were randomised into two groups. Group 1: topical silicone gel plus herbal extract gel (Allium cepa, Centella Asiatica, Aloe vera and Paper Mulberry) and Group 2: silicone gel. Patients were treated for six months. The postoperative scars were assessed at three and six months by plastic surgeons using the Vancouver Scar Scale (VSS) and the patient assessment scar scale.

RESULTS

Each group comprised 23 patients (n=46 in total). The VSS was significantly lower in Group 1 than in Group 2 (p=0.018 and p=0.051, respectively). In Group 1, the four differences from baseline were vascularity scores at three and six months (-0.391, p=0.025; -0.435, p=0.013, respectively), and pigmentation scores at three and six months (-0.391, p=0.019; -0.609, p=0.000, respectively). In Group 2, differences from baseline were the pigmentation and vascularity score at six months (-0.6609, p=0.000; -0.348, p=0.046, respectively).

CONCLUSION

Our results suggest, post-sternotomy scars trend to have better vascularity and pigmentation when treated with silicone gel plus herbal extracts.

The effect of silicone gel versus contractubex gel on the upper-extremity postsurgical scars: A randomized, double-blinded, controlled trial

Background: Wound healing is a process that has three overlapping inflammatory, proliferative, and reconstruction phases. Silicone gel and Contractubex (onion extract gel) are two main topical agents used for the prevention and treatment of hypertrophic scars. This clinical trial study aimed to evaluate the efficacy and safety of onion extract and silicone gel on hypertrophic scars of the upper extremity and compare it to non-treated patients.

Methods: This randomized, double-blind, parallel, clinical trial was done on 120 male patients who had undergone upper extremity sharp injury repair. Patients were assigned to three groups, i.e., Silicone gel (Kelo-cort^TM; WA, USA) (group 1; 40 patients), Onion extract (Contractubex^TM, Merz Pharma, Frankfurt, Germany) gel (group 2; 40 patients), and No Intervention (group 3; 40 patients), using drawing sealed envelopes and a computer-based table of randomization. Data were recorded using the Vancouver scale in each visit by two surgeons who were blinded to the study groups. IBM SPSS Statistics for Windows, Version 22.0. (Armonk, NY: IBM Corp). Data were compared using the ANOVA test. A P-value of less than 0.05 was considered statistically significant.

Results: Vascularity (p=0.200), pliability (p=0.058), pigmentation (p=0.701), and height (p=0.438) as subjective scar parameters were approximately similar in post-upper extremity sharp injury wound hypertrophic scar among the three groups.

Conclusion: Vascularity, pliability, pigmentation and height, as subjective scar parameters, were not statistically different in post-upper extremity sharp injury wound hypertrophic scar among the groups. Even though onion extract gel and Silicone gel show preventive effects in the literature, especially in burns wounds, further studies are recommended to be conducted to prove the topical effects of above-mentioned gels in patients.

A Prospective Randomized Double-blind study of silicone gel plus Herbal Extracts Versus Placebo in Pre-sternal hypertrophic scar prevention and amelioration

Objective

Post-surgical hypertrophic scar is more frequently reported in Asians. Many modalities can treat scars but there have not been any publications to define the efficacy of silicone gel plus herbal extracts for scar prevention or amelioration.

Design

48 patients, who underwent median sternotomy were randomized and double-blinded to 2 groups to use topical silicone gel plus herbal extract gel or placebo for 6 months. Patients were treated either with topical silicone gel plus herbal extract gel or control using only placebo for 6 months. The scars were observed by experienced plastic surgeons using the Vancouver scar scale.

Setting

A single tertiary care center at Khon Kaen University.

Paticipants

48 patients who underwent median sternotomy were enrolled in this study. All patients were aged over 18 years. All the wounds were sutured with polyglycolic 4/0 subcuticular suture material and did not receive other scar management before participating in this study.

Intervention

The silicone gel plus herbal extract gel (Bangkok Botanica, Bangkok, Thailand) in semi-liquid form was formulated from 15% Herbal extract (Allium Cepa extract, Centella Asiatica extract, Aloe Vera extract and Paper Mulberry extract), 50% polydemethysiloxane, 30% cyclopentasiloxane and 5% silica. The placebo gel was a composite of water, acrylate, C10-30 alkyl acrylate cross-polymer, polysorbate 20 and fragrance that was similar in color and consistency as that of the active gel and packed in the similar sealed packages.

Main outcome measures

The scar was assessed using the Vancouver scar scale to determine pigmentation, vascularity, pliability and height.

Results

the study showed the silicone gel plus herbal extract gel could improve scar amelioration in height (p = 0.005) and pliability (p < 0.001) when compared to the placebo. The vascularity and pigmentation showed improvement using silicone gel plus herbal extracts but the improvement was not statistically significant.

Conclusion

The silicone gel plus herbal extracts gel was effective for scar improvement in median sternotomy wounds.

Laser pretreatment for the attenuation of planned surgical scars: A randomized self-controlled hemi-scar pilot study

BACKGROUND

Nonsurgical scar attenuation options include compression garments, silicone gel, intralesional drug therapy, radiation therapy, laser, and light therapies. Laser application preceding surgical intervention has been shown to modify the wound-healing process and affect subsequent scar formation. The objective of this study was to evaluate the safety, efficacy, and final cosmesis of a single presurgical laser treatment on surgical scar formation.

METHODS

This was a randomized, controlled, intraindividual split-scar pilot study with blinded assessments of treated versus untreated planned incision sites. One half of each planned scar was treated by means of an Erbium glass, 1540 nm laser, 24 h before surgery, and the other half was not treated and served as the control. Clinical evaluations and the measurements of patient and physician POSAS scales were done at 1 and 12 months following surgery.

RESULTS

Eleven patients completed the study and were included in the analyses. Laser pretreatment showed a significant beneficial effect compared with no treatment. Both the patient and physician mean Patient and Observer Scar Assessment Scale scores were significantly lower for the laser-treated half of the scars compared with the control side (1.55 to 3.00, p = 0.02 and 2.28 to 4.42, p = 0.03). There was a highly significant interobserver correlation in the evaluation of the overall posttreatment changes (r = 0.904, p < 0.001).

CONCLUSION

A single presurgical laser treatment of a planned incision site is a simple, safe, and painless strategy to significantly improve the final scar appearance.

Autologous emulsified fat injection for rejuvenation of scars: A prospective observational study

Background:

The skin rejuvenation potential of the autologous emulsified nanofat was studied by Tonnard et al. in 2013. This property is due to the viable adipose-derived stem cells present in the nanofat; although, there are no viable adipocytes. The aim of this study was to determine the aesthetic outcome of autologous emulsified nanofat injection in scars using a standardised and validated Patient Observer Scar Assessment Scale (POSAS) and photographs.

Materials and Methods:

A total of 34 patients with scars of varied aetiologies were included in the study as per inclusion criteria. Pre-operative scoring of the scars with the POSAS scale was done, and photographs were taken. Fat aspiration was done from the lower abdominal wall using syringe liposuction under tumescent anaesthesia. The lipoaspirate was mechanically emulsified, filtered and injected intralesionally into the scar using 26G needle and insulin syringe. Post-operative scar reassessment was done at 3 months with the POSAS scale score and photographs. The improvement in scar characteristics and symptoms were tested statistically using a paired t-test. Pre-operative and post-operative photographic comparison was also done.

Results:

Out of the 34 patients included in the study, male:female ratio was 22:12. Majority (79.4%) had post-traumatic facial scars. On statistical analysis, there was statistically significant improvement in symptoms such as pain (P = 0.001), itching (P = 0.001), stiffness (P = 0.001), thickness (P = 0.001), colour (P = 0.001), irregularity (P = 0.001) and scar characteristics such as vascularity (P = 0.005), relief (P = 0.001), pliability (P = 0.001), thickness (P = 0.001) and pigmentation (P = 0.001) 3 months after injection. The photographic comparison also showed good aesthetic outcome.

Conclusion:

Autologous emulsified nanofat injection is effective in improving the scar characteristics as well as symptoms and helps in scar rejuvenation.

In vivo terahertz imaging to evaluate scar treatment strategies: silicone gel sheeting

Silicone gel sheeting (SGS) is widely used for scar treatment; however, studies showing its interaction with skin and efficacy of scar treatment are still lacking. THz light is non-ionizing and highly sensitive to changes in water content and thus skin hydration. In this work, we use in-vivo THz imaging to monitor how SGS affects the THz response of human skin during occlusion, and the associated THz reflectivity and refractive index changes are presented. We find that SGS effectively hydrates the skin beneath it, with minimal lateral effects beyond the sheeting. Our work demonstrates that THz imaging is able to detect the subtle hydration changes on the surface of human skin caused by SGS, and it has the potential to be used to evaluate different scar treatment strategies.

Safety and Efficacy of a Scar Cream Consisting of Highly Selective Growth Factors Within a Silicone Cream Matrix: A Double-Blinded, Randomized, Multicenter Study

BACKGROUND

Several growth factors and hyaluronic acid are implicated in fetal scarless healing. Whether these factors can be applied to an adult scar to improve scar characteristics is unknown.

OBJECTIVES

This study compared the efficacy and safety of SKN2017B, a proprietary topical cream consisting of selective synthetic recombinant human growth factors and hyaluronic acid in a silicone base containing a specifically formulated silicone cream for postsurgical scar treatment.

METHODS

In this prospective, randomized, controlled, double-blinded study, unilateral or bilateral facial or truncal scars in adult surgical patients were randomly treated with SKN2017B or silicone cream. Study investigators, study patients, and 2 independent reviewers assessed improvement in scar characteristics after 4 and 12 weeks of treatment.

RESULTS

Forty-nine bilateral and 12 unilateral scars in 45 patients were treated with SKN2017B or silicone. At 12 weeks, investigators rated 74% of scars treated with SKN2017B as showing overall improvement vs 54% of silicone-treated scars, a 73% relative improvement with SKN2017B (P < 0.0001). Patients rated a moderate-to-significant improvement in 85% of SKN2017B-treated scars vs 51% of silicone-treated scars, a 67% relative improvement with SKN2017B (P < 0.001). Independent reviewers rated 87% of scars treated with SKN2017B to be better overall vs 1% of scars treated with silicone (P < 0.0001). There were no tolerability issues or adverse reactions with either cream.

CONCLUSIONS

SKN2017B consists of highly selective growth factors within a silicone cream matrix and is well tolerated and effective for surgical scar management.

LEVEL OF EVIDENCE: 1

Advances in the treatment of traumatic scars with laser, intense pulsed light, radiofrequency, and ultrasound

Traumatic scarring is one of the most common complications after soft tissue injury caused by burns and trauma, which affects tens of millions of people worldwide every year. Traumatic scars diminish the quality of life due to disfigurement, symptoms of pain and itch, and restricted motion. The pathogenesis and pathophysiology of traumatic scar remain elusive. The management for traumatic scars is comprised of surgical and non-surgical interventions such as pressure therapy, silicone, corticosteroid, and radiotherapy, which are chosen by clinicians based on the physical examinations of scars. Recently, great progress in treating traumatic scars has been achieved by the development of novel technologies including laser, intense pulsed light (IPL), radiofrequency, and ultrasound. The aim of this review article was to summarize the advances of these technologies for traumatic scars intervention.

Gene expression analysis in scars treated with silicone cream: a case series

BACKGROUND

In contrast to fetal scar tissue, adult scar tissue presents with visible scarring. Topical silicone creams have been shown to improve the appearance of scars. This case series compares the genetic expression of post-surgical scar tissues that received topical scar treatment with silicone cream, SKN2017B, or no treatment. SKN2017B is a recently formulated silicone-based scar cream that contains selective synthetic recombinant human growth factors, hyaluronic acid, and vitamin C. We hypothesise that scars treated with silicone-based scar creams have a more favourable genetic expression resembling a well-healing scar.

METHODS

Women who had undergone an abdominoplasty were included in this investigation and randomly assigned to treat part of the scar with topical silicone, another part with SKN2017B, and to leave a third part untreated. After four weeks, punch biopsies were taken and the RNA sequenced. Healthy abdominal skin was biopsied as baseline data. Genes of interest were identified and median values were calculated for the samples.

RESULTS

SKN2107B-treated scars demonstrated the lowest collagen type I to collagen type III ratio. Other key genes of interest in wound healing showed the lowest (favourable) expression of fibroblast activation protein alpha, lysyl oxidase and cartilage oligomeric matrix protein; the highest (favourable) expression of fibronectin type III domain containing 1 and matrix metallopeptidase 9 were found in scars treated with SKN2017B.

CONCLUSION

The results of this small case series demonstrate a trend that those scars treated with topical silicone cream, notably SKN2017B, display the most favourable gene expression for wound healing.

Small Molecular TGF-β1-Inhibitor-Loaded Electrospun Fibrous Scaffolds for Preventing Hypertrophic Scars

Hypertrophic scarring (HS) is a disorder that occurs during wound healing and seriously depresses the quality of human life. Scar-inhibiting scaffolds, though bringing promise to HS prevention, face problems such as the incompatibility of the scaffold materials and the instability of bioactive molecules. Herein, we present a TGF-β1-inhibitor-doped poly(ε-caprolactone) (PCL)/gelatin (PG) coelectrospun nanofibrous scaffold (PGT) for HS prevention during wound healing. The appropriate ratio of PCL to gelatin can avoid individual defects of the two materials and achieve an optimized mechanical property and biocompatibility. The TGF-β1 inhibitor (SB-525334) is a small molecule and is highly stable during electrospinning and drug release processes. The PGT effectively inhibits fibroblast (the major cell type contributing to scar formation) proliferation in vitro and successfully prevents HS formation during the healing of full-thickness model wounds on rabbit ear. Our strategy offers an excellent solution for potential large-scale production of scaffolds for clinical HS prevention.

Effect of P144® (Anti-TGF-β) in an "In Vivo" Human Hypertrophic Scar Model in Nude Mice

Background

Hypertrophic scars are one of the most important complications in surgery due to their cosmetic and functional impairments. Previous studies in tissue fibrotic disorders have shown promising results by inhibiting the biological activity effect of Transforming Growth Factor-beta 1 (TGF-β1). The aim of the current study was to determine the clinical effect of the inhibition of TGF-β1 signaling in human hypertrophic scars implanted in nude mice by topical application of an inhibitor of TGF-β1 (P144®).

Material and Methods

A total of 30 human hypertrophic scars were implanted in 60 nude mice. The animals were divided in two groups, group A (placebo) and group B (treatment). Group C (basal) was considered as the preimplanted scar samples and they were not implanted in the nude mice. After the shedding period, topical application of a lipogel containing placebo (group A) or P144 (group B) was daily administered during two weeks. The animals were sacrificed upon completion of the study. Total area, thickness and collagen fibers area were measure and compared across all groups. Immunohistochemistry was also performed in order to quantify collagen type I and type III and elastic fiber expressions present in the dermis.

Results

Successful shedding was achieved in 83,3% of the xenografts. The mean time for shedding was 35±5.4 days. Statistically significant differences were found in the total area, collagen fibers area and thickness between the groups. Increased elastic fibers and decreased collagen I were found in the P144-treated group compared to the basal group.

Conclusion

Topical application of an inhibitor of TGF-β1 may promote scar maturation and clinical improvement of hypertrophic scar morphology features in an “in vivo” model in nude mice after two weeks of treatment.

Prevention of postsurgical scars: comparsion of efficacy and convenience between silicone gel sheet and topical silicone gel

To date, few studies have compared the effectiveness of topical silicone gels versus that of silicone gel sheets in preventing scars. In this prospective study, we compared the efficacy and the convenience of use of the 2 products. We enrolled 30 patients who had undergone a surgical procedure 2 weeks to 3 months before joining the study. These participants were randomly assigned to 2 treatment arms: one for treatment with a silicone gel sheet, and the other for treatment with a topical silicone gel. Vancouver Scar Scale (VSS) scores were obtained for all patients; in addition, participants completed scoring patient questionnaires 1 and 3 months after treatment onset. Our results reveal not only that no significant difference in efficacy exists between the 2 products but also that topical silicone gels are more convenient to use. While previous studies have advocated for silicone gel sheets as first-line therapies in postoperative scar management, we maintain that similar effects can be expected with topical silicone gel. The authors recommend that, when clinicians have a choice of silicone-based products for scar prevention, they should focus on each patient's scar location, lifestyle, and willingness to undergo scar prevention treatment.

Update on scar management: guidelines for treating Asian patients

BACKGROUND

Following injury, Asian skin has a tendency towards hyper-pigmentation and scar formation, and therefore the prevention of scarring is particularly important in Asian patients. Since publication of an International Clinical Recommendation on Scar Management in 2002, there have been numerous publications in the field of scar management. Advances in understanding scar formation have also led to the introduction of new treatments as well as a better understanding of established therapeutic options.

METHODS

A literature search for abstracts, clinical trials and meta-analyses evaluating scar prevention and treatment was performed using PubMed and the Cochrane Database of Systematic Reviews. Based on this data a panel of experts formulated treatment recommendations for Asian patients.

RESULTS

Following surgery, scar prevention should be initiated in all Asian patients due to the high risk of poor scars. There is strong evidence for the efficacy of silicone based products, and due to their ease of use, they can be considered first-line therapy. Silicone gel (versus silicone gel sheets) products have demonstrated efficacy. For patients who fail to respond to first-line therapy, intralesional steroid injections, radiation therapy, and intralesional 5-flourouracil injections have achieved widespread acceptance. Laser treatments have been increasingly used, although the evidence remains largely anecdotal without a clear consensus on optimal wavelength, or amount of energy. Surgical approaches have increased in sophistication with recognition of the impact that tension has on scar formation.

CONCLUSION

Updated scar management recommendations will benefit practitioners making decisions regarding optimal, evidence-based treatment strategies for their patients.

Scar management by means of occlusion and hydration: a comparative study of silicones versus a hydrating gel-cream

Despite the worldwide use of silicones in scar management, its exact working mechanism based on a balanced occlusion and hydration, is still not completely elucidated. Moreover, it seems peculiar that silicones with completely different occlusive and hydrating properties still could provide a similar therapeutic effect. The objective of the first part of this study was to compare the occlusive and hydrating properties of three fluid silicone gels and a hydrating gel-cream. In a second part of the study these results were compared with those of silicone gel sheets. Tape stripped skin was used as a standardized scar like model on both forearms of 40 healthy volunteers. At specific times, trans epidermal water loss (TEWL) and the hydration state of the stratum corneum were measured and compared with intact skin and a scar-like control over a 3-4h period. Our study clearly demonstrated that fluid silicone gels and a hydrating gel-cream have comparable occlusive and hydrating properties while silicone gel sheets are much more occlusive, reducing TEWL values far below those of normal skin. A well-balanced, hydrating gel-cream can provide the same occlusive and hydrating properties as fluid silicone gels, suggesting that it could eventually replace silicones in scar treatment.

Role of silicone derivative plus onion extract gel in presternal hypertrophic scar protection: a prospective randomized, double blinded, controlled trial

Use of silicone derivative and onion extract had been reported in the prevention of hypertrophic scarring. Our experience showed the preventive use of silicone derivative plus onion extract gel on hypertrophic scars after median sternotomy. In a randomized, double blinded, placebo-controlled study, 60 patients after median sternotomy incisions were separated into two groups. All patients were treated either with silicone derivative plus onion extract gel (Cybele(®) scagel) or placebo gel twice daily for a total treatment period of 12 weeks. During each visit, pain and itching scores were graded by the patients and scar characteristics were observed by surgeons using the Vancouver scar scale. Pain and itch score values from patients' who applied silicone derivative plus onion extract gel was less than another group (P < 0·05). Pigmentation was significantly different between two groups (P < 0·05) and the reduction of scores on vascularity, pliability, height in treated group was not superior to the untreated group. No adverse events were reported by any of the patients. A silicone derivative plus onion extract gel is safe and effective for the preventing the hypertrophic scarring after median sternotomy.