Twenty-five years of active laser prevention of scars: What have we learned?

Asiatic acid-entrapped transfersomes for the treatment of hypertrophic scars: In vitro appraisal, bioactivity evaluation, and clinical study

Non-invasive treatment options for hypertrophic scars (HTS) are limited, and treating HTS remains challenging due to their unappealing appearance and associated social stigma. In this work, a novel transfersomal system named Asiatic acid-entrapped transfersomes (AATs) was prepared. AATs were evaluated for their skin permeability, anti-inflammatory activity, and other characteristic parameters to determine the most promising formulation. Asiatic acid-entrapped transfersomal gel (AATG), which was obtained by incorporating the lead AATs in a gel base, underwent testing in an 8-week, double-blind, placebo-controlled, split-skin clinical study. The net skin elasticity (R5), melanin index (MI), and skin surface hydration were analyzed employing Cutometer®, Mexameter®, and Corneometer®, respectively, in order to evaluate the effectiveness of the developed AATG. AATs exhibited vesicular sizes and zeta potential values within the range of (27.15 ± 0.95 to 63.54 ± 2.51 nm) and (-0.010 to -0.129 mV), respectively. TW80AAT gave the highest %EE (90.84 ± 2.99%), deformability index (101.70 ± 11.59 mgs-1), permeation flux at 8 h (0.146 ± 0.005 mg/cm2/h), and anti-inflammatory activity (71.65 ± 1.83%). The clinical study results of AATG indicated no adverse skin reactions. Furthermore, product efficacy tests demonstrated a significant reduction in MI and an increase in net skin elasticity at 2, 4, and 8 weeks. These pilot study outcomes support the effectiveness of the AATG.

Laser Combined with Radiotherapy for Keloid Treatment: A Novel and Efficient Comprehensive Therapy with a Lower Recurrence Rate

BACKGROUND

Keloids are a fibroproliferative skin disorder with a high recurrence rate. Combined therapies are often used in clinical treatment, but, in addition to the relatively high risk of relapse and complexity of the treatment process, side effects remain unknown for combination therapies.

METHODS

A total of 99 patients with keloids in 131 positions were included in this retrospective study. Fractional CO 2 laser therapy was first applied with energy ranging from 360 to 1008 mJ; then, 6-Mev, 900-cGy electron beam irradiation was applied twice. The first pass was initiated within 24 hours after the laser therapy, and the second pass was performed on the seventh day after laser therapy. The Patient and Observer Scar Scale evaluated the lesions before the treatment and at 6, 12, and 18 months after treatment. At each follow-up visit, the patients filled out a questionnaire on recurrence, side effects, and satisfaction.

RESULTS

The authors found a significant decrease in total Patient and Observer Scar Scale score [29 (23, 39) versus 61.2 ± 13.4; P < 0.001] at the 18-month follow-up compared with the baseline value (before the therapy). A total of 12.1% of the patients had recurrences during the 18-month follow-up period (11.1% partial recurrence and 1.0% complete recurrence). The total satisfaction rate was 97.0%. No severe adverse effects were observed during the follow-up period.

CONCLUSIONS

Laser combined with radiotherapy is a new comprehensive therapy comprising ablative lasers and radiotherapy for keloids. It had excellent clinical efficacy, low recurrence rate, and no serious adverse effects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Scar Therapy of Skin

Scar therapy is truly important in medicine. Patients experience great loss in quality of life with scars. There are many treatment modalities that help treat scars, including topical, intralesional, surgical, and energy-based devices. In addition, early intervention can help mitigate scar formation. Lasers represent a major innovation in the treatment of all types of scars. Treating scars is a multimodal and multispecialty endeavor. This article highlights the use of many therapies to treat scars and scar symptoms including pruritus, pain, and range of motion. This also highlights key literature including multiple recent consensus guidelines in treating scars.

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.

Topical gel containing Polysiloxanes and hyaluronic acid for skin scar: Formulation design, characterization, and In vivo activity

BACKGROUND

Scar formation is undesirable both cosmetically and functionally. It shows that silicone gel is effective in preventing and improving scars formed due to a wound formation after injury.

OBJECTIVES

This study investigates whether a silicone gel composition based on a novel concept of infusing a biologically active material such as hyaluronic acid and/or salts with various polysiloxane derivatives in a specific proportion to achieve desired viscosity range and their action has a synergistic beneficial effect on skin scar after injury.

METHODS

We have developed a topical gel utilizing a combination of emulsifiers, sodium hyaluronate, polysiloxane, and its derivatives. The method of preparation comprises mixing of aqueous phase dispersion and polysiloxanes blend under stirring at room temperature.

RESULTS

It results in the formation of a homogenous smooth gel formulation. The developed topical gel formulation was characterized for physicochemical properties, rheology, stability, and anti-scar activity in Wistar rats. It was found that the developed formulation system consists of desirable attributes for skin applications. In vivo investigation of developed polysiloxane gel formulation for anti-scar activity shown promising outcomes compared to marketed product (Kelo-cote scar gel). Furthermore, a histopathology study of healed skin tissues observed the formation of microscopic skin structures compared to the Kelo-cote scar gel.

CONCLUSIONS

It indicates that the combination of polysiloxanes and sodium hyaluronate resulting an improvement in anti-scar activity compared to the marketed product containing polysiloxanes alone.

Laser Resurfacing for the Management of Periorbital Scarring

Laser (light amplification by the stimulated emission of radiation) skin resurfacing is currently one of the most widely adopted technologies in facial rejuvenation. While most often used for aesthetic purposes, lasers also have applications in the management of scars. Since the introduction of the CO₂ laser for skin rejuvenation in the 1990s, the last three decades have seen significant growth in the number of laser devices available to the physician. More recently, promising alternatives to light-based resurfacing technologies have emerged that include radiofrequency and intense focused ultrasound. To help the physician navigate the most current laser technologies as they apply to periocular scars, this review discusses the available treatment modalities, pre-treatment assessment of periorbital scars, treatment selection, and reported outcomes and complications. The recommendations described herein are based on published literature and the authors' experience in an academic oculoplastics practice.

The effects of valsartan on scar maturation in an experimental rabbit ear wound model

INTRODUCTION

In our study, we aimed to search and compare the effects of valsartan and enalapril on the pathological scar formation on the basis of histomorphological parameters.

MATERIALS AND METHODS

Nine New Zealand albino male rabbits, which were divided into three groups, were included in the study. A previously described rabbit ear wound model was used. Enalapril was administered 0.75 mg/kg/day on the first group and valsartan was administered 10 mg/kg/day on the second group for 40 days. The third group was the control group. Results were evaluated on the 40th day with scar elevation index calculation and histological studies. Histological studies were done by using Hematoxylin-eosin, Masson trichrome and Sirius Red stains.

RESULTS

Enalapril and valsartan groups were both significantly effective on the prevention of pathological scar formation when compared to the control group in terms of fibroblast count, capillary count, type 1/3 collagen ratio, collagen organization, and epithelial thickness. There was no significant difference between the enalapril and control group on the scar elevation index. Valsartan group was more efficient than the enalapril group on the reduction of fibroblast count and epithelial thickness.

CONCLUSION

Both Valsartan and Enalapril are found to be effective for the prevention of pathological scar formation.

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.

Effect of pressure therapy for treatment of hypertrophic scar

BACKGROUND

Pressure therapy (PST) has been reported for the treatment of hypertrophic scar (HS) effectively. However, no study has assessed its effect and safety systematically. Therefore, this study will investigate its effect and safety for patients with HS.

METHODS

A comprehensive literature search will be performed from the electronic databases and grey literatures. The electronic databases include MEDILINE, EMBASE, Cochrane Library, Web of Science, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. All of them will be searched from inception to the present without language restrictions. Any randomized controlled trials on assessing the effect and safety of PST on HS will be considered for inclusion. In addition, we will also search grey literature to avoid missing any potential studies. RevMan V.5.3 software will be utilized for statistical analysis.

RESULTS

This study will provide the most recent evidence of PST on HS by evaluating primary outcomes of scar pruritus and improvement of scar; and secondary outcomes of scar blood flow, elasticity, volume, pain and burning. In addition, we will also evaluate adverse events.

CONCLUSION

This study will provide up-to-date evidence of PST in patients with HS.Systematic review registration: PROSPERO CRD42019136627.

Early laser intervention to reduce scar formation - a systematic review

The ability of laser treatment to affect wound healing and subsequently minimize scar formation has been investigated in recent years. However, no systematic review links these clinical trials. The aim of this study was to systematically review and evaluate clinical evidence for early laser intervention to reduce scar formation in studies where laser treatment was introduced less than 3 months after wounding. We searched PubMed using relevant keywords in June 2017. Titles, abstracts and articles were sorted according to inclusion and exclusion criteria. Methodological quality was evaluated according to Cochrane Collaborations risk-of-bias assessment guideline by two independent authors. Twenty-five articles met the inclusion criteria. In total, 22 of 25 studies were controlled studies, and 17 of 25 studies compared laser treatment vs. untreated control scars. The following laser devices have been investigated: pulsed dye laser (PDL), potassium-titanyl-phosphate (KTP) laser, fractional erbium:glass 1540 nm/1550 nm, fractional/full ablation erbium-doped yttrium aluminium garnet (Er:YAG) laser or fractional CO2 laser. Eighteen studies applied laser treatments 2-4 times with 2- to 8-week intervals, while seven studies applied only one laser treatment. Follow-up time ranged from 1 to 12 months with 18 studies using a follow-up time ≤3 months. In general, laser-treated wounds and scars showed benefit from laser intervention, though not always reaching significance. Significant scar improvement was found in three of four studies using laser treatment in inflammation phase, in six of 16 studies with laser initiated in the proliferation phase and in two of five studies in the remodelling phase. High risk of bias was found in randomization and allocation concealment, and low risk of bias with regard to blinding of outcome assessment and lost to follow-up. In conclusion, laser intervention when introduced in inflammation, proliferation or remodelling phase has the potential to reduce cutaneous scar formation. Further, high-quality studies are needed before standard protocols can be implemented in clinical practice.

Posttraumatic Laser Treatment of Soft Tissue Injury

Laser treatment for posttraumatic injury offers the clinician the unique opportunity for early intervention in mediating early scar formation, or for reducing the appearance of scars after maturation. In this review, the authors focus on the mechanisms by which lasers exert their therapeutic effects, highlighting several popular lasers and dosimetry used, and underscoring the power of combined surgical scar revision in managing posttraumatic facial scars.

A 1-Year Follow-Up of Post-operative Scars After the Use of a 1210-nm Laser-Assisted Skin Healing (LASH) Technology: A Randomized Controlled Trial

BACKGROUND

Laser therapies are used prophylactically for excessive scar formation. The Laser-Assisted Skin Healing treatment induces a controlled heat stress that promotes tissue regeneration. This comparative trial is the first to evaluate the performance of a new automated 1210-nm laser system, compatible with all Fitzpatrick scale phototypes.

METHODS

Forty women undergoing bilateral breast reduction were enrolled in this double-blinded randomized controlled trial. The horizontal sutured incision of one breast was treated with the portable 1210-nm laser while in the operating theatre. The other breast was used as the study control. Objective measurements, subjective clinical assessments and safety evaluation were carried out over 1 year by both clinicians and patients.

RESULTS

Six weeks following surgery, better overall appearance and modified OSAS scores were reported for the laser-treated scars when compared to the control group (p = 0.024 and p = 0.079). This supports an early effect of the laser treatment during the inflammatory stage of the healing process. After a post-treatment period of 6 months, there continued to be a strong tendency in favour of the laser treatment based on the subjective scores and corroborated by the objective improvement of the treated scar volume (p = 0.038). At 1 year, the laser-treated scars continued to improve compared to the control ones in terms of volume (p = 0.004), surface (p = 0.017) and roughness (p = 0.002), and these comparatively better results were strengthened with the blind expression of patients' preference for their laser-treated scar (p = 0.025).

CONCLUSIONS

This new 1210-nm laser treatment, used as a single session performed immediately after surgery, provides significant objective and subjective improvements in scar appearance. These data can be useful when preparing patients to undergo their surgical procedure.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. 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 .

Treatment of keloid scars with a 1210-nm diode laser in an animal model

BACKGROUND AND OBJECTIVE

A temperature increase can improve wound healing by activation of heat shock protein 70 and stimulation of fibroblasts. Since keloids are a dysfunction of collagen fiber synthesis and organization, this study aimed to evaluate if a 1,210 nm diode laser could have effects in a new animal model of keloid scars.

STUDY DESIGN/MATERIALS AND METHODS

A total of 39 nude mice were used for this study. Phototypes IV and V human keloids were grafted into their backs and after 1 month of healing, the mice were divided into four groups: Control, Laser, Resection, Resection/Laser. In the Laser group, the keloids were treated with a 1,210-nm diode-laser with the following parameters: 4 W; 10 seconds; fluence: 51 J/cm(2) ; spot: 18.9 × 3.7 mm(2) . In the Resection group, surgical intra-lesional excision was performed. In the Resection/Laser group, keloids were treated with the 1,210-nm laser-diode after surgical intra-lesional excision. Temperature measurements were made during the laser treatment. Clinical examination and histological study were performed on the day of treatment and 1 month, 2 months, and 3 months later.

RESULTS

Mean temperature measurement was of 44.8°C (42-48°) in the Laser groups. No healing complications or keloid proliferation was observed in any group. Keloid histologic characters were confirmed in all grafts. No histologic particularity was observed in the laser groups in comparison with the Control and Resection groups.

CONCLUSION

First, this keloid animal model appears to be adapted for laser study. Secondly, the 1,210-nm diode laser does not induce keloid thermal damage in vivo. Further studies with different 1,210-nm laser diode parameters should be performed in order to observe significant effects on keloids.

Update on hypertrophic scar treatment

Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin.

Outcomes of ablative fractional laser scar treatment

Ablative fractional laser (AFL) systems are commonly used to treat various scars, and recent reports have indicated that early scar treatment with fractional lasers has good aesthetic results. Some scars respond dramatically to AFL treatment, incurring high levels of patient satisfaction; however, other scars respond poorly or became worse after treatment. This study was designed to clarify prognostic factors that predict AFL scar treatment outcomes. A total of 108 patients were included in this study. The fractional laser treatments were repeated every 4 weeks until the scar site was acceptable and no additional improvement was expected or the patient discontinued the treatment. The scar improvements were defined as changes in the Manchester scar scale (MSS) from before to after laser treatment. A digital camera was used to acquire digital photographs of the scars under the same light source, the same background, exposure, and white balance. This study developed a modification of the MSS for image analysis in which colour assessment was based on L*a*b* colour co-ordinates of the digital images. The mean MSS values prior to and after laser treatments were 11.6 ± 3.6 and 9.5 ± 2.9, respectively (p < 0.01). AFL treatment improved the qualities of each scar, and the improvements were evident in colour and contour. Scar elevation, pigmentation, high vascularity, early onset of treatment, and the number of treatment sessions were directly related to scar improvement after AFL therapy (p < 0.05). AFL treatments were effective methods for scar treatment. Clinicians can use these prognostic factors to determine treatment plans and to estimate scar improvement after AFL treatment.

Treatment of surgical scars using a 595-nm pulsed dye laser using purpuric and nonpurpuric parameters: a comparative study

BACKGROUND

Many studies have examined laser treatment of scars, but cosmetic results have been variable. Although no studies have examined the effect of purpura on scar improvement using the pulsed dye laser (PDL), many clinicians believe inducing purpura results in better and quicker improvement.

OBJECTIVE

To determine whether PDL treatment of fresh surgical scars with purpura-inducing settings improves clinical appearance more than non-purpura-inducing settings or no treatment.

METHODS

Twenty-six subjects with surgical scars enrolled in this prospective study. Scars were divided into three equal segments; treatment was randomized: 595-nm PDL with purpuric (1.5 ms) or nonpurpuric (10 ms) settings or no treatment. Fluences were adjusted to Fitzpatrick skin type. Scars were treated three times, 1 month apart, beginning at suture removal. Outcome measures included Vancouver Scar Scale (VSS) and blind clinical ratings.

RESULTS

The nonpurpuric condition showed significant improvement on the VSS total score, vascularity, and pliability ratings. The purpuric condition demonstrated a trend for improvement on the VSS total. According to blind observer ratings, all conditions improved, without differences between groups.

CONCLUSION

Nonpurpuric settings on the PDL resulted in significant improvements in the appearance of fresh surgical scars for vascularity, pliability, and VSS total scores, although all scar segments improved over time.

A preliminary study of the safety of red light phototherapy of tissues harboring cancer

OBJECTIVE

Red light phototherapy is known to stimulate cell proliferation in wound healing. This study investigated whether low-level light therapy (LLLT) would promote tumor growth when pre-existing malignancy is present.

BACKGROUND DATA

LLLT has been increasingly used for numerous conditions, but its use in cancer patients, including the treatment of lymphedema or various unrelated comorbidities, has been withheld by practitioners because of the fear that LLLT might result in initiation or promotion of metastatic lesions or new primary tumors. There has been little scientific study of oncologic outcomes after use of LLLT in cancer patients.

METHODS

A standard SKH mouse nonmelanoma UV-induced skin cancer model was used after visible squamous cell carcinomas were present, to study the effects of LLLT on tumor growth. The red light group (n=8) received automated full body 670 nm LLLT delivered twice a day at 5 J/cm(2) using an LED source. The control group (n=8) was handled similarly, but did not receive LLLT. Measurements on 330 tumors were conducted for 37 consecutive days, while the animals received daily LLLT.

RESULTS

Daily tumor measurements demonstrated no measurable effect of LLLT on tumor growth.

CONCLUSIONS

This experiment suggests that LLLT at these parameters may be safe even when malignant lesions are present. Further studies on the effects of photoirradiation on neoplasms are warranted.

Prospective ex-vivo study on thermal effects in human skin phototypes II, IV and VI: a comparison between the 808, 1064, 1210 and 1320-nm diode laser

BACKGROUND

Laser Assisted Skin Healing (LASH) was first introduced in 2001 by Capon and Mordon to prevent keloids and hypertrophic scars. LASH requires homogenous heating throughout the full thickness of the skin around the wound. However, LASH therapy with 808-nm diode laser is deemed to be only applicable for phototype I-IV due to melanin absorption. This prospective ex-vivo study aims to evaluate the thermal effects of different wavelengths (808, 1064, 1210 and 1320 nm) on human skin phototype II, IV and VI.

MATERIAL AND METHODS

Laser shots were applied on skin explants phototypes II, IV and VI. The following laser settings were used: 808, 1064, 1210 and 1320-nm diode laser, Spot size 20 × 3.7 mm, Power 3 W, Irradiance 4 W/cm², 50 shots for each phototype and wavelength. The surface temperature at 2 and 4-mm depth respectively was evaluated by an infrared camera and a low inertia micro thermocouple.

RESULTS

For the 1064, 1210 and 1320-nm wavelengths, the temperature gradient between the surface and 2-mm depth after an irradiation time of 15 s was less than 4.0°C for each phototype. For the 808 nm, the gradient was 0.8°C and 4.4°C in phototype II and IV respectively, but reached 17.2°C in phototype VI. Strong absorption by melanin of skin phototype VI induced unwanted temperature increases at the dermis-epidermis junction, making this wavelength unsuitable for LASH therapy for this phototype. Among the three other wavelengths, the discussion section indicates strong blood absorption at 1064 nm and presents both 1210 and 1320 nm as excellent compromises for LASH therapy across the whole range of phototypes.

CONCLUSION

Being poorly absorbed by melanin, both 1210 and 1320-nm wavelengths ensure homogeneity of temperature throughout the full skin explant thickness. Their possible utilization for efficient LASH therapy should now be confirmed by prospective in vivo studies.

A novel composition for in vitro and in vivo regeneration of skin and connective tissues

The particular combination of polydeoxyribonucleotides, l-carnitine, calcium ions, proteolytic enzyme and other ingredients acts in a synergetic way in the regeneration of skin and connective tissues. This new formulation of active principles was tested in vitro as a cell and tissue culture medium and in vivo for various preparations in support of tissue regeneration. In vitro, the new blend allowed the maintenance of skin biopsies for more than 1 year in eutrophic conditions. Immunocytochemical analyses of fibroblasts isolated from these biopsies confirmed a significant increase of the epidermal and connective wound-healing markers such as collagen type I, collagen type IV, cytokeratin 1 (CK1), CK5, CK10 and CK14 versus controls. To examine the effects of the new compound in vivo, we studied impaired wound healing in genetically diabetic db/db mice. At day 18, diabetic mice treated with the new composition showed 100% closure of wounds and faster healing than mice treated with the other solutions. This complex of vital continuity factors or life-keeping factors could be used as a tissue-preserving solution or a cosmetic/drug/medical device to accelerate wound healing in the treatment of patients with deficient wound repair to promote the regeneration of cutaneous and connective tissues (injuries-wound, dermatitis) and prevent the recurrent relapses.