Immunohistochemical investigation of wound healing in response to fractional photothermolysis

Ablative fractional CO2 laser treatment promotes wound healing phenotype in skin macrophages

OBJECTIVES

Ablative fractional laser (AFL) treatment is a well-established method for reducing signs of skin photoaging. However, the biological mechanisms underlying AFL-induced healing responses and skin rejuvenation remain largely unknown. It is known that macrophages play an important role in orchestrating healing, normalization, and remodeling processes in skin. Macrophage phenotypes are characterized by inflammatory markers, including arginase-1 (Arg1), major histocompatibility class II molecules (MHC II), and CD206. This study aims to explore AFL's effect on macrophage phenotype by evaluating changes in inflammatory markers and the potential concurrent accumulation of Arg1 in the skin.

METHODS

Mice (n = 9) received a single AFL treatment on the left side of the back skin (100 mJ/microbeam, 5% density) while the right side of the back remained untreated as control. Treated and untreated skin from each mouse were collected Day 5 posttreatment for flow cytometry and histology analysis. Flow cytometry evaluated the immune infiltration of macrophages and the expression of macrophage inflammatory markers (Arg1, MHC II, and CD206). In addition, Arg1 presence in the skin was evaluated through antibody staining of histology samples and quantification was performed using QuPath image analysis software.

RESULTS

Following AFL, the number of macrophages increased 11-fold (p = 0.0053). Phenotype analysis of AFL-treated skin revealed an increase in the percentage of macrophages positive for Arg1 (p < 0.0001) and a decrease in the percentage of macrophages positive for MHC II (p < 0.0001) compared to untreated skin. No significant differences were observed in percentage of CD206-positive macrophages (p = 0.8952). Visualization of AFL-treated skin demonstrated a distinct pattern of Arg1 accumulation that correlated with the microscopic treatment zones (MTZ). Quantification of the percentage of Arg1-positive area in epidermis and dermis showed a significant increase from 3.5% ± 1.2% to 5.2% ± 1.7 (p = 0.0232) and an increase from 2.2% ± 1.2% to 9.6% ± 3.3 (p < 0.0001) in whole skin samples.

CONCLUSION

AFL treatment polarizes macrophages toward a wound healing phenotype and induces Arg1 accumulation in the MTZ. We propose that the polarized wound healing macrophages are a major source for the increased Arg1 levels observed in the skin following treatment.

Early acne scar intervention with 1064 nm picosecond laser in patients receiving oral isotretinoin: a randomized split-face controlled pilot study

Early acne scar intervention is important. Oral isotretinoin is widely used in patients with moderate to severe acne. Picosecond laser has shown a promising effect on scar clearance. However, there is a lack of reports on the efficacy and safety of early acne scar management by using 1064-nm picosecond laser in patients receiving low-dose oral isotretinoin. Twenty-four patients with atrophic acne scars of Fitzpatrick skin type III to V were enrolled. All patients were receiving low-dose oral isotretinoin (0.12-0.22 mg/kg/day) during the treatment. The face of the participants was randomly assigned to receive 2 sessions of fractional picosecond 1064 nm Nd: YAG laser (FxPico) treatment and 2 follow-ups, with an interval of 1 month (month 0-3). Clinical efficacy and safety were assessed by photographs, ECCA grading scale, the number of scar lesions melanin and erythema indexes (MI and EI), TEWL, DLQI, and patient satisfaction and the adverse events were recorded on every visit. FxPico significantly decreased the ECCA score and showed higher improvement in the ECCA score. FxPico treated side achieved a significant reduction in all acne scar types, while only boxcar scars and rolling scars showed higher improvement. TEWL but not MI or EI were significantly improved. DLQI and patient satisfaction were higher with the FxPico-treated side than control side. No adverse effects were observed and all the side effects observed were temporary and tolerable. Early intervention by FxPico on patients receiving low-dose oral isotretinoin is a safe and effective modality to improve atrophic acne scars.

Ablative fractional carbon dioxide laser improves quality of life in patients with extensive burn scars: A nested case-control study

BACKGROUND AND OBJECTIVES

Ablative fractional carbon dioxide laser (CO₂ -AFL) for small-area burn scar management shows encouraging outcomes. Few studies, however, focused on comprehensive outcomes following CO₂ -AFL treatment for extensive burn scars. This study evaluated whether CO₂ -AFL surgery improved the quality of life (QoL) for burn survivors with extensive hypertrophic scars.

METHODS

A retrospective nested case-control study was initiated to analyze the efficacy of CO₂ -AFL treatment for patients with large-area burn scars. Patients with extensive burn scars (≥30% total body surface area [TBSA]) were registered in our hospital from March 2016 to October 2018. Patients undergoing CO₂ -AFL surgery were divided into CO₂ -AFL group, and patients undergoing conventional surgery were matched in a 1:1 ratio as the conventional surgery group according to the burned area. The questionnaires were collected and followed up. The 36-Item Short Form Health Survey (SF-36) and Burns Specific Health Scale-Brief (BSHS-B) were the primary parameters. Secondary parameters included the Pittsburgh Sleep Quality Index (PSQI), University of North Carolina "4P" Scars Scale (UNC4P), Patient Scars Assessment Scale for Patient (POSAS-P), and Douleur Neuropathique 4 questions (DN4).

RESULTS

23 patients (55.96 ± 21.59% TBSA) were included in CO₂ -AFL group and 23 patients (57.87 ± 18.21% TBSA) in conventional surgery group. Both the BSHS-B total score (CO₂ -AFL vs. conventional surgery: 115.35 ± 29.24 vs. 85.43 ± 33.19, p = 0.002) and the SF-36 total score (CO₂ -AFL vs. conventional surgery: 427.79 ± 118.27 vs. 265.65 ± 81.66, p < 0.001) for the CO₂ -AFL group were higher than those for the conventional surgery group. Parameters for the CO₂ -AFL group were lower than those for the conventional surgery group in all of the following comparisons: PSQI total score (CO₂ -AFL vs. conventional surgery: 7.70 ± 3.74 vs. 12.26 ± 4.61, p = 0.001), POSAS-P total score (CO₂ -AFL vs. conventional surgery: 26.48 ± 6.60 vs. 33.04 ± 4.56, p < 0.001), UNC4P total score (CO₂ -AFL vs. conventional surgery: 5.57 ± 1.97 vs. 7.26 ± 1.81, p = 0.004), and DN4 score (CO₂ -AFL vs. conventional surgery: 3 [2-5] vs. 5 [4-8], p = 0.004).

CONCLUSIONS

Compared to conventional surgery, whole scar CO₂ -AFL surgery dramatically improved physical and mental health as well as QoL for people with extensive burn scars. Additionally, CO₂ -AFL enhanced the evaluation of scars including their appearance, pain, itching, and a host of other symptoms.

Anti-PD-1 Therapy with Adjuvant Ablative Fractional Laser Improves Anti-Tumor Response in Basal Cell Carcinomas

Simple Summary

In some mouse models, ablative fractional laser (AFL) enhances the efficacy of anti-programmed cell death1 therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC). In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant BCC model. BCC-carrying mice received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. Both aPD-1 and AFL alone significantly increased survival time relative to the untreated controls, while aPD-1 that had been complemented with AFL further promoted survival and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in tumors and increased the levels of relevant immune cell subtypes. Thus, the anti-tumor response that was generated by aPD-1 with adjuvant AFL may potentially be promoted by increased immune activity in tumors. In conclusion, the use of a local AFL adjuvant to systemic aPD-1 therapy could hold substantial promise for BCC treatment.

Abstract

The efficacy of anti-programmedcelldeath1therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC) treatment, can be enhanced by adjuvant ablative fractional laser (AFL) in syngeneic murine tumor models. In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant autochthonous BCC model. BCC tumors (n = 72) were induced in Ptch1^+/−K14-CreER2p53^fl/fl-mice (n = 34), and the mice subsequently received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. The outcome measures included mouse survival time, tumor clearance, tumor growth rates, and tumor immune infiltration. Both aPD-1 and AFL alone significantly increased survival time relative to untreated controls (31 d and 34.5 d, respectively vs. 14 d, p = 0.0348–0.0392). Complementing aPD-1 with AFL further promoted survival (60 d, p = 0.0198 vs. aPD-1) and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in the tumors. Similar to AFL alone, combined aPD-1 and AFL increased neutrophil counts (4-fold, p = 0.0242), the proportion of MHCII-positive neutrophils (p = 0.0121), and concordantly, CD4⁺ and CD8⁺ T-cell infiltration (p = 0.0061–0.0242). These descriptive results suggest that the anti-tumor response that is generated by aPD-1 with adjuvant AFL is potentially promoted by increased neutrophil and T-cell engraftment in tumors. In conclusion, local AFL shows substantial promise as an adjuvant to systemic aPD-1 therapy in a clinically relevant preclinical BCC model.

Transcriptomic analysis of human skin wound healing and rejuvenation following ablative fractional laser treatment

Ablative fractional laser treatment is considered the gold standard for skin rejuvenation. In order to understand how fractional laser works to rejuvenate skin, we performed microarray profiling on skin biopsies to identify temporal and dose-response changes in gene expression following fractional laser treatment. The backs of 14 women were treated with ablative fractional laser (Fraxel®) and 4 mm punch biopsies were collected from an untreated site and at the treated sites 1, 3, 7, 14, 21 and 28 days after the single treatment. In addition, in order to understand the effect that multiple fractional laser treatments have on skin rejuvenation, several sites were treated sequentially with either 1, 2, 3, or 4 treatments (with 28 days between treatments) followed by the collection of 4 mm punch biopsies. RNA was extracted from the biopsies, analyzed using Affymetrix U219 chips and gene expression was compared between untreated and treated sites. We observed dramatic changes in gene expression as early as 1 day after fractional laser treatment with changes remaining elevated even after 1 month. Analysis of individual genes demonstrated significant and time related changes in inflammatory, epidermal, and dermal genes, with dermal genes linked to extracellular matrix formation changing at later time points following fractional laser treatment. When comparing the age-related changes in skin gene expression to those induced by fractional laser, it was observed that fractional laser treatment reverses many of the changes in the aging gene expression. Finally, multiple fractional laser treatments, which cover different regions of a treatment area, resulted in a sustained or increased dermal remodeling response, with many genes either differentially regulated or continuously upregulated, supporting previous observations that maximal skin rejuvenation requires multiple fractional laser treatments. In conclusion, fractional laser treatment of human skin activates a number of biological processes involved in wound healing and tissue regeneration.

Laser Immunotherapy: A Potential Treatment Modality for Keratinocyte Carcinoma

Simple Summary

In light of expanding incidences of keratinocyte carcinoma (KC) with many patients developing multiple tumors, the demand for new treatment modalities is high. With the approval of cemplimab for locally advanced and metastasizing basal cell carcinoma and squamous cell carcinoma, KC is now included as an indication for systemic immunotherapy. At present, however, systemic KC therapy remains limited by the severe side effects associated with treatment. Immunotherapy might be more broadly applied if locally administered. Localized to the skin, KCs are easily accessible to topical drugs and physical interventions such as laser. There is an increasing appreciation of lasers’ potential to activate an immune response. Further enhancement of the laser-based immune activation might be obtained by combining laser and immunotherapeutic agents, known as laser immunotherapy. In search of new treatment modalities for KC and aiming to broaden the field of KC immunotherapy, this review discusses the current literature on immune activation following both laser monotherapy and laser immunotherapy.

Abstract

The role of the immune system in cancer growth is well recognized and the development of immunotherapy represents a breakthrough in cancer treatment. Recently, the use of systemic immunotherapy was extended to keratinocyte carcinoma (KC), specifically locally advanced and metastasizing basal and squamous cell carcinoma. However, since most KC lesions are non-aggressive, systemic treatment with associated side effects is rarely justified. Conversely, topical immunotherapy with imiquimod remains restricted to premalignant and superficial lesions. Use of laser in the treatment of KC has evolved from physical tumor destruction and laser-assisted drug delivery to laser-mediated immune modulation. Evidence indicates that laser monotherapy can lead to immune cell infiltration, tumor reduction and resistance to tumor re-inoculation. Combining laser with immunotherapeutic agents, termed laser immunotherapy (LIT), may further potentiate immune activation and tumor response. Studies on LIT show not only direct anti-tumor effects but systemic adaptive immunity, illustrated by the prevention of tumor recurrence and regression in distant untreated tumors. These findings imply a therapeutic potential for both local and metastatic disease. This work provides rationales for immune-based treatment of KC and presents the current status of KC immunotherapy. Aiming to expand the field of KC immunotherapy, the review discusses the literature on immune activation following laser monotherapy and LIT.

Ablative fractional CO2 laser surgery improving sleep quality, pain and pruritus in adult hypertrophic scar patients: a prospective cohort study

Background

Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars, combined with pruritus and pain. Few interventions have been reported to improve the sleep quality of patients with scars. In the current prospective cohort study, we investigated the efficacy of CO₂-ablative fractional laser (AFL) surgery vs conventional surgery in post-burn patients with hypertrophic scars with sleep quality as the primary study outcome.

Methods

In total 68 consecutive patients undergoing scar surgical treatment were recruited, including a CO₂-AFL surgery cohort (n = 35) and a conventional surgery cohort (n = 33). A subgroup from the AFL cohort was selected. Sleep quality, pain and pruritus were evaluated. Multiple linear regression analyses were performed to reveal the effect of CO₂-AFL surgery.

Results

The CO₂-AFL surgery cohort had significantly lower Pittsburgh sleep quality index (PSQI) global scores than the conventional surgery cohort after the last surgical treatment. In the subgroup of patients receiving hardware sleep monitoring, CO₂-AFL markedly increased deep sleep time, deep sleep efficiency and reduced initial sleep latency. Compared to the conventional surgery cohort, the CO₂-AFL cohort presented significantly lower pain and pruritus scores. Correlation analysis showed pain and pruritus were significantly associated with PSQI scores, and there were also significant correlations between pain and pruritus scores. Multiple linear regression analysis showed that surgery method was negatively linearly correlated with visual analog scale (VAS) pain score, brief pain inventory (BPI) total, VAS pruritus score, 5-D itch scale total, four-item itch questionnaire (FIIQ) total and PSQI total.

Conclusions

CO₂-AFL surgery significantly improved sleep quality and reduced pain and pruritus of hypertrophic scar patients. The alleviation of sleep disorder was associated with improvement of deep sleep quality including deep sleep time and deep sleep deficiency.

Trial registration

The Chinese Clinical Trial Registry (ChiCTR200035268) approved retrospectively registration on 5 Aug 2020.

Early Treatment Effects of Nonablative Fractional Lasers (NAFL) on Hypertrophic Scars in an Animal Model

BACKGROUND AND OBJECTIVES

Recently, there have been several attempts to apply the laser therapy to hypertrophic scars (HTS). In particular, the fractional laser is in the spotlight for its usefulness in rapid wound healing and dermal remodeling. However, most previous studies have focused on the ablative fractional laser (AFL), and there are no studies on the mechanism of the nonablative fractional laser (NAFL) effect in HTS treatment. In this study, we aimed to evaluate the changes in histology and molecular chemistry to provide scientific evidence for the early treatment of HTS with NAFL.

STUDY DESIGN/MATERIALS AND METHODS

A total of 40 hypertrophic burn scars were made on the abdomens of two female pigs. After epithelialization, the HTS were randomly subdivided into four groups-control, AFL, NAFL (low energy), and NAFL (high energy). Laser treatment was initiated 1 week after the crust fell and the epithelium became covered, and it was repeated for six sessions over an interval of 2 weeks. Five excisional biopsies were obtained for histologic analysis and biomarker assessment.

RESULTS

Histologically, dermal remodeling with thin coil-shaped collagen fibers was observed in the NAFL groups. It also showed a significant increase of matrix metalloproteinase-2 (MMP-2) and Decorin at 16 weeks in an enzyme-linked immunosorbent assay. The reverse-transcription polymerase chain reaction analysis showed a tendency that high-pulse energy of NAFL led to higher messenger RNA expression than did the low-energy group.

CONCLUSION

The NAFL-treated groups showed characteristic collagen re-arrangement and a significant increase in MMP-2 and Decorin. These molecular changes suggest that MMP-2 and Decorin play a significant role in dermal remodeling. Early NAFL treatment for HTS could be supported with both histological and molecular evidence. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Stimulation of collagen and elastin production in-vivo using 1,540 nm Er:Glass laser: assessment of safety and efficacy

Introduction: Induction of collagen and elastin remodeling in the human skin can be achieved by non-ablative fractional laser (NAFXL) and ablative fractional laser (AFXL). Our objective was to compare the safety, efficacy, tolerability, and ability to induce collagen and elastin remodeling of NAFXL versus AFXL in a series of treatments over time.Materials and Methods: In this prospective, proof of principle, single-case study, the safety, tolerability and efficacy of the laser systems were assessed via histopathology and clinical evaluations including photographs. Optical biopsies by means of multiphoton tomography (MPT) were used to evaluate the induction of collagen and elastin remodeling.Results: Treatments by both NAFXL and AFXL were well tolerated. The NAFXL system was found to be less painful and resulted in a shorter down- and healing times. MPT findings showed the superior capability of the AFXL procedure to induce collagen; on the other hand, elastin induction was more pronounced after NAFXL treatments.Conclusions: While NAFXL is as effective and safe as the traditional AFXL, it is better tolerated and has a shorter downtime. Serial optical biopsies over time over time can be a useful tool to assess the induction of collagen and elastin remodeling in the human skin.

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.

When Wounds Are Good for You: The Regenerative Capacity of Fractional Resurfacing and Potential Utility in Chronic Wound Prevention

Significance: Fractional resurfacing involves producing arrays of microinjuries on the skin, by thermal or mechanical means, to trigger tissue regeneration. Originally developed for cosmetic enhancement, fractional resurfacing induces a broad array of improvements in the structural and functional qualities of the treated skin and is especially effective at returning defective skin to a more normal state. In addition to fascinating questions about the nature of this remarkable regenerative capacity, there may be potential utility in ulcer prevention by halting or even reversing the progressive decline in overall skin quality that usually precedes chronic wound development. Recent Advances: Photoaging and scarring are the two skin defects most commonly treated by fractional resurfacing, and the treatment produces profound and long-lasting improvements in skin quality, both clinically and at the cellular/histologic level. Chronic wounds usually occur in skin that is compromised by various pathologic factors, and many of the defects found in this ulcer-prone skin are similar to those that have seen improvements after fractional resurfacing. Critical Issues: The mechanisms responsible for the regenerative capacity of fractional resurfacing are mostly unknown, as is how ulcer-prone skin, which is usually afflicted by stressors external to the skin tissue itself, would respond to fractional resurfacing. Future Directions: Better understanding of the cellular and molecular mechanisms underlying the unique healing response to fractional resurfacing could reveal fundamental information about adult tissue regeneration, lead to improvements in current applications, as well as new therapies in other pathologic conditions.

Early intervention of fractional carbon dioxide laser on fresh traumatic scar

To determine the combined therapeutic effect of fractional carbon dioxide laser and silicone gel on fresh traumatic scars using a rabbit ear hypertrophic scar (EHS) model, as well as on human subjects. The rabbit EHS model was established by punching four circular wounds in each ear and respectively treated with carbon dioxide laser, silicone gel, and the combination of both, while one wound was left untreated. In addition, a validation group of five rabbits was also included wherein the wounds were treated with triamcinolone, IFN-α, and normal saline, with one untreated control. The gross hyperplasic changes and the histological features were analyzed, and the scar elevation index (SEI) was calculated for each treatment group. In the rabbit model, the untreated control wounds showed hypertrophic growth, whereas triamcinolone or IFN-α showed an inhibitory effect, similar to that on hypertrophic scars in humans, thereby proving the feasibility of our animal model. The SEI peaked 2 months after treatment and was respectively 2.28 ± 0.56, 1.85 ± 0.33, 1.91 ± 0.34, and 1.45 ± 0.22 in the untreated control, and the silicone, laser, and combined treatment groups, clearly indicating a significant therapeutic effect of the combined treatment modality (p < 0.01). The fibroblast and microvascular counts also showed similar trends in each group. Early application of fractional carbon dioxide laser can prevent hypertrophic scars; the combined use of laser and silicone gel was more effective with less recovery time, thereby worthy of clinical promotion.

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.

The comparison of skin rejuvenation effects of vitamin A, fractional laser, and their combination on rat

BACKGROUND

Because of long-term exposure of skin, skin aging is an unavoidable natural law with age. Traditional Vitamin A and novel ablative fractional laser technique both have the effects of skin rejuvenation, and studies have demonstrated both of them have apparent clinical efficacy and histology-improving effects on photo-aging skin.

MATERIALS AND METHODS

45 female healthy Wistar rats were selected and the depilation areas of every rat were divided into four regions: control region(Region A), Vitamin A acid region(Region B), combination treatment region(Region C), and fractional laser region(Region D). 0.025% Vitamin A acid cream was applied to Region B and C every day for 3 weeks; Region C and D were irradiated once with 10600nm CO₂ fractional laser on the first day of the trail. The skin tissue was dissected and placed into liquid nitrogen according to the design. The real-time quantitative PCR and western blotting methods were taken to detect the expression changes of miR-29a, Akt, TGF-β, and mRNA of type III pre-collagen.

RESULTS

It can be seen from the results of the real-time quantitative PCR that the mRNA expression levels of type III pre-collagen, Akt, and TGF-β in the treatment regions are up-regulated and the expression levels of miR-29a mRNA are down-regulated compared to the Region A. The hybridization tests showed that changes of the expression of type III pre-collagen, Akt gene, miR-29a gene, and TGF-β gene across the experiment regions are all significantly different in the third week, and the expression levels of them all achieve the highest value in the third week, the expression level of miR-29a gene achieves the lowest value in the third week, which are consistent with the results of real-time quantitative PCR.

CONCLUSION

It is indicated that the combination region of Vitamin A acid and fractional laser may lead to low expression of miR-29a, thus the inhibition of downstream Akt activation is loss, Akt activation is enhanced, enhancement of the expression of TGF-β is induced, leading to proliferation of fibroblasts, and promotion of the collagen proteins' synthesis in skin. Therefore miR-29a/Akt/TGF-β signal pathway may participate in the skin rejuvenation mechanism of action Vitamin A acid and fractional laser. This may provide a new treatment approach for skin rejuvenation.

Early treatment using fractional CO2 laser before skin suture during scar revision surgery in Asians

Fractional CO₂ laser is one of the most effective treatment options used to resurface scars. However, most previous studies have been performed on mature scars at least 2 months after surgery. Recent studies have emphasized the importance of early treatment to reduce scar formation. In the present study, we described our experience with fractional CO₂ laser intervention before skin suture during scar revision surgery in Asians, and found the treatment was safe and effective.

Fractional CO2 laser treatment of caesarean section scars-A randomized controlled split-scar trial with long term follow-up assessment

BACKGROUND AND OBJECTIVES

Caesarean section (c-section) scars can be pose functional and cosmetic challenges and ablative fractional laser (AFXL) treatment may offer benefit to patients. We evaluated textural and color changes over time in AFXL-treated versus untreated control scars.

MATERIALS AND METHODS

A randomized, controlled, intra-individual split-scar trial with three sessions of AFXL-treatments for mature c-section scars. Settings of AFXL were adjusted to each individual scar. End-points were blinded on-site clinical evaluations at 1, 3, and 6 months follow-up (Patient and Observer Scar Assessment Scale [POSAS] and Vancouver Scar Scale [VSS]), blinded photo-evaluations, reflectance measurements, tissue histology, and patients satisfaction.

RESULTS

Eleven of 12 patients completed the study. At 1 month follow-up, AFXL-treated scars were significantly improved in pliability (POSAS P = 0.01 VSS P = 0.02) and smoother in surface relief (POSAS P = 0.03) compared to control scars. At 1-3 months, overall scar appearance was dominated by transient erythema and hyperpigmentation, confirmed by reflectance measurements (erythema% and pigmentation% peaked at 1 and 3 month follow-up, respectively). At 6 months follow-up, AFXL-treated scars improved on POSAS-total score though not significantly (P = 0.06). Correspondingly, blinded photo-evaluation found AFXL-treated scars significantly improved compared to controls (VAS P = 0.02). Histology indicated new dermal collagen and elastic fibers on AFXL-treated scars. At 6 months follow-up, a majority of patients (64%) favored subsequent AFXL-treatment of their untreated control scar tissue.

CONCLUSIONS

Scar remodeling is initiated 1 month after AFXL treatment, but overall scar improvement is concealed until laser-induced color changes resolve. At 6 months follow-up, the benefit of AFXL treatment on c-section scars emerges. Lasers Surg. Med. 49:189-197, 2017. © 2016 Wiley Periodicals, Inc.

The effect of microablative fractional CO2 laser on vaginal flora of postmenopausal women

OBJECTIVES

To assess the effect of microablative fractional CO2 laser (MFCO2-Laser) therapy on the vaginal microenvironment of postmenopausal women.

METHODS

Three laser therapies at monthly intervals were applied in postmenopausal women with moderate to severe symptoms of genitourinary syndrome of menopause, pH of vaginal fluid >4.5 and superficial epithelial cells on vaginal smear <5%. Vaginal fluid pH values, fresh wet mount microscopy, Gram stain and aerobic and anaerobic cultures were evaluated at baseline and 1 month after each subsequent therapy. Nugent score and Hay-Ison criteria were used to evaluate vaginal flora.

RESULTS

Fifty-three women (mean age 57.2 ± 5.4 years) participated and completed this study. MFCO2-Laser therapy increased Lactobacillus (p < 0.001) and normal flora (p < 0.001) after the completion of the therapeutic protocol, which decreased vaginal pH from a mean of 5.5 ± 0.8 (initial value) to 4.7 ± 0.5 (p < 0.001). The prevalence of Lactobacillus changed from 30% initially to 79% after the last treatment. Clinical signs and symptoms of bacterial vaginosis, aerobic vaginitis or candidiasis did not appear in any participant.

CONCLUSION

MFCO2-Laser therapy is a promising treatment for improving the vaginal health of postmenopausal women by helping repopulate the vagina with normally existing Lactobacillus species and reconstituting the normal flora to premenopausal status.

Controlled Release of Chitosan and Sericin from the Microspheres-Embedded Wound Dressing for the Prolonged Anti-microbial and Wound Healing Efficacy

One approach in wound dressing development is to incorporate active molecules or drugs in the dressing. In order to reduce the frequency of dressing changes as well as to prolong wound healing efficacy, wound dressings that can sustain the release of the active molecules should be developed. In our previous work, we developed chitosan/sericin (CH/SS) microspheres that released sericin in a controlled rate. However, the difficulty of applying the microspheres that easily diffuse and quickly degrade onto the wound was its limitations. In this study, we aimed to develop wound dressing materials which are easier to apply and to provide extended release of sericin. Different amounts of CH/SS microspheres were embedded into various compositions of polyvinyl alcohol/gelatin (PVA/G) scaffolds and fabricated using freeze-drying and glutaraldehyde crosslinking techniques. The obtained CH/SS microspheres-embedded scaffolds with appropriate design and formulation were introduced as a wound dressing material. Sericin was released from the microspheres and the scaffolds in a sustained manner. Furthermore, an optimized formation of the microspheres-embedded scaffolds (2PVA2G+2CHSS) was shown to possess an effective antimicrobial activity against both gram-positive and gram-negative bacteria. These microspheres-embedded scaffolds were not toxic to L929 mouse fibroblast cells, and they did not irritate the tissue when applied to the wound. Finally, probably by the sustained release of sericin, these microspheres-embedded scaffolds could promote wound healing as well as or slightly better than a clinically used wound dressing (Allevyn®) in a mouse model. The antimicrobial CH/SS microspheres-embedded PVA/G scaffolds with sustained release of sericin would appear to be a promising candidate for wound dressing application.

Scar Management in the Pediatric and Adolescent Populations

For most children and adolescents who have developed symptomatic scars, cosmetic concerns are only a portion of the motivation that drives them and their caregivers to obtain treatment. In addition to the potential for cosmetic disfigurement, scars may be associated with a number of physical comorbidities including hypertrichosis, dyshidrosis, tenderness/pain, pruritus, dysesthesias, and functional impairments such as contractures, all of which may be compounded by psychosocial factors. Although a plethora of options for treating scars exists, specific management guidelines for the pediatric and adolescent populations do not, and evidence must be extrapolated from adult studies. New modalities such as the scar team approach, autologous fat transfer, and ablative fractional laser resurfacing suggest a promising future for children who suffer symptomatically from their scars. In this state-of-the-art review, we summarize cutting-edge scar treatment strategies as they relate to the pediatric and adolescent populations.

Lasers and ancillary treatments for scar management: personal experience over two decades and contextual review of the literature. Part I: Burn scars

The formation of a wide range of excessive scars following various skin injuries is a natural consequence of healing. Scars resulting from surgery or trauma affect approximately 100 million people per annum in the developed world and can have profound physical, aesthetic, psychological and social consequences. Thus, scar treatment is a priority for the plastic surgeon. We aim to explore new approaches to the management of such scarring. The senior authors current use of laser technology, chemotherapeutic agents, pharmacotherapy and cryosurgery will be reviewed. This is placed in the context of the current literature and evidence base and is illustrated with case studies, starting with burns scars in part I, and focusing on keloid and hypertrophic scars in part II, acne scars in part III and finally pigmented scars in part IV. In Part I we focus on burns scar treatment with fractional ablative 10,600 nm wavelength carbon dioxide (CO2) laser therapy.

Up-regulation of Hsp72 and keratin16 mediates wound healing in streptozotocin diabetic rats

Background

Impaired wound healing is a complication of diabetes and a serious problem in clinical practice. We previously found that whey protein (WP) was able to regulate wound healing normally in streptozotocin (STZ)-diabetic models. This subsequent study was designed to assess the effect of WP on heat shock protein-72 (Hsp72) and keratin16 (Krt16) expression during wound healing in diabetic rats.

Methods

WP at a dosage of 100 mg/kg of body weight was orally administered daily to wounded normal and STZ-diabetic rats for 8 days.

Results

At day 4, the WP-treated diabetic wound was significantly reduced compared to that in the corresponding control. Diabetic wounded rats developed severe inflammatory infiltration and moderate capillary dilatation and regeneration. Treated rats had mild necrotic formation, moderate infiltration, moderate to severe capillary dilatation and regeneration, in addition to moderate epidermal formation. Hsp72 and Krt16 densities showed low and dense activity in diabetic wounded and diabetic wounded treated groups, respectively. At day 8, WP-treatment of diabetic wounded animals revealed great amelioration with complete recovery and closure of the wound. Reactivity of Hsp72 and Krt16 was reversed, showing dense and low, or medium and low, activity in the diabetic wounded and diabetic wounded treated groups, respectively. Hsp72 expression in the pancreas was found to show dense reactivity with WP-treated diabetic wound rats.

Conclusion

This data provides evidence for the potential impact of WP in the up-regulation of Hsp72 and Krt16 in T1D, resulting in an improved wound healing process in diabetic models.

Case report: rapidly healing epidermolysis bullosa wound after ablative fractional resurfacing

Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating genodermatosis characterized by generalized skin fragility, severe blistering, and wounding that heals with mutilating scarring. Patients are in constant need of effective wound therapies as they often succumb to aggressive metastatic squamous cell carcinomas or to sepsis that may develop from their chronic wounds. Herein, we demonstrate accelerated wound healing with use of a fractionated CO2 laser protocol in a 22-year-old man with RDEB. His 9-month-old, non-healing wound decreased from 7 cm in diameter to 2 cm in diameter (a 92% reduction in wound surface area) within 4 weeks of a single laser treatment, and he had near-complete re-epithelialization within 4 weeks of his second laser treatment without blistering or other adverse effects. This novel intervention of using fractionated CO2 for photo-microdebridement could help revolutionize wound care for patients who have RDEB and whose chronic wounds serve as one of their greatest sources of morbidity and mortality. Dissemination to a pediatric audience is critical so that laser protocols might be more thoroughly investigated and incorporated into wound management strategies for this uniquely vulnerable population.

Residual scarring from hidradenitis suppurativa: fractionated CO2 laser as a novel and noninvasive approach

Hidradenitis suppurativa (HS) is a chronic, relapsing, inflammatory skin condition that can have a significant psychosocial impact, both with the active disease and with residual scarring. Although a wide variety of treatment options exist for HS, to our knowledge there are no reported modalities aimed specifically at treating HS scarring. We describe the case of an adolescent female who received medical management of intramammary HS followed by successful treatment with fractionated 10,600-nm carbon dioxide laser for her residual cribriform scarring. We believe there is great potential for the use of fractionated carbon dioxide laser to improve short- and long-term psychosocial outcomes of HS, promote physical scar remodeling, and possibly alter the disease process itself.

Ablative fractional resurfacing for the treatment of traumatic scars and contractures

After a decade of military conflict, thousands of wounded warriors have suffered debilitating and cosmetically disfiguring scars and scar contractures. Clearly, there is a need for effective scar treatment regimens to assist in the functional and cosmetic rehabilitation of these patients. Traditional treatments, including aggressive physical and occupational therapy and dedicated wound care, are essential. Adjunctive treatments with established laser technologies, such as vascular lasers and full-field ablative lasers, have had a somewhat limited role in scar contractures due to modest efficacy and/or an unacceptable side effect profile in compromised skin. Refractory scar contractures often require surgical revision, which can be effective, but is associated with additional surgical morbidity and a significant risk of recurrence. Furthermore, current scar treatment paradigms often dictate scar maturation for approximately a year to allow for spontaneous improvement before surgical intervention. Since 2009, the Dermatology Clinic at the Naval Medical Center San Diego has been treating scars and scar contractures in wounded warriors and others using ablative fractionated laser technology. Although traditionally associated with the rejuvenation of aged and photo-damaged skin, our clinical experience and a handful of early reports indicate that laser ablative fractional resurfacing demonstrates promising efficacy and an excellent side effect profile when applied to the functional and cosmetic enhancement of traumatic scars and contractures. This article discusses our clinical experience with ablative fractional resurfacing and its potential prominent role in rehabilitation from traumatic injuries, including a possible shift in scar treatment paradigms toward earlier procedural intervention. Potential benefits include the optimization of scar trajectory and higher levels of full or adapted function in a more favorable time course.

Direct quantitative comparison of molecular responses in photodamaged human skin to fractionated and fully ablative carbon dioxide laser resurfacing

BACKGROUND

Fractionated ablative laser resurfacing has become a widely used treatment modality. Its clinical results are often found to approach those of traditional fully ablative laser resurfacing.

OBJECTIVE

To directly compare the molecular changes that result from fractionated and fully ablative carbon dioxide (CO(2)) laser resurfacing in photodamaged human skin.

METHODS AND MATERIALS

Photodamaged skin of 34 adult volunteers was focally treated at distinct sites with a fully ablative CO(2) laser and a fractionated CO(2) laser. Serial skin samples were obtained at baseline and several time points after treatment. Real-time reverse transcriptase polymerase chain reaction technology and immunohistochemistry were used to quantify molecular responses to each type of laser treatment.

RESULTS

Fully ablative and fractionated CO(2) laser resurfacing induced significant dermal remodeling and collagen induction. After a single treatment, fractionated ablative laser resurfacing resulted in collagen induction that was approximately 40% to 50% as pronounced as that induced by fully ablative laser resurfacing.

CONCLUSIONS

The fundamental cutaneous responses that result from fully ablative and fractionated carbon dioxide laser resurfacing are similar but differ in magnitude and duration, with the fully ablative procedure inducing relatively greater changes including more pronounced collagen induction. However, the molecular data reported here provide substantial support for fractionated ablative resurfacing as an effective treatment modality for improving skin texture.

Fractional CO2 laser resurfacing for atrophic acne scars: a randomized controlled trial with blinded response evaluation

BACKGROUND

The treatment of acne scars with fractional CO(2) lasers is gaining increasing impact, but has so far not been compared side-by-side to untreated control skin.

OBJECTIVE

In a randomized controlled study to examine efficacy and adverse effects of fractional CO(2) laser resurfacing for atrophic acne scars compared to no treatment.

METHODS

Patients (n = 13) with atrophic acne scars in two intra-individual areas of similar sizes and appearances were randomized to (i) three monthly fractional CO(2) laser treatments (MedArt 610; 12-14 W, 48-56 mJ/pulse, 13% density) and (ii) no treatment. Blinded on-site evaluations were performed by three physicians on 10-point scales. Endpoints were change in scar texture and atrophy, adverse effects, and patient satisfaction.

RESULTS

Preoperatively, acne scars appeared with moderate to severe uneven texture (6.15 ± 1.23) and atrophy (5.72 ± 1.45) in both interventional and non-interventional control sites, P = 1. Postoperatively, lower scores of scar texture and atrophy were obtained at 1 month (scar texture 4.31 ± 1.33, P < 0.0001; atrophy 4.08 ± 1.38, P < 0.0001), at 3 months (scar texture 4.26 ± 1.97, P < 0.0001; atrophy 3.97 ± 2.08, P < 0.0001), and at 6 months (scar texture 3.89 ± 1.7, P < 0.0001; atrophy 3.56 ± 1.76, P < 0.0001). Patients were satisfied with treatments and evaluated scar texture to be mild or moderately improved. Adverse effects were minor.

CONCLUSIONS

In this single-blinded randomized controlled trial we demonstrated that moderate to severe atrophic acne scars can be safely improved by ablative fractional CO(2) laser resurfacing. The use of higher energy levels might have improved the results and possibly also induced significant adverse effects.

Histological evaluation of vertical laser channels from ablative fractional resurfacing: an ex vivo pig skin model

Ablative fractional resurfacing (AFR) represents a new treatment potential for various skin conditions and new laser devices are being introduced. It is important to gain information about the impact of laser settings on the dimensions of the created laser channels for obtaining a safe and efficient treatment outcome. The aim of this study was to establish a standard model to document the histological tissue damage profiles after AFR and to test a new laser device at diverse settings. Ex vivo abdominal pig skin was treated with a MedArt 620, prototype fractional carbon dioxide (CO(2)) laser (Medart, Hvidovre, Denmark) delivering single microbeams (MB) with a spot size of 165 μm. By using a constant pulse duration of 2 ms, intensities of 1-18 W, single and 2-4 stacked pulses, energies were delivered in a range from 2-144 mJ/MB. Histological evaluations included 3-4 high-quality histological measurements for each laser setting (n = 28). AFR created cone-shaped laser channels. Ablation depths varied from reaching the superficial dermis (2 mJ, median 41 μm) to approaching the subcutaneous fat (144 mJ, median 1,943 μm) and correlated to the applied energy levels in an approximate linear relation (r(2) = 0.84, p < 0.001). The dermal ablation width increased slightly within the energy range of 4-144 mJ (median 163 μm). The thickness of the coagulation zone reached a plateau around 65 μm at energies levels above 16 mJ. The calculated volumes of ablated tissue increased with increasing energies. We suggest this ex vivo pig skin model to characterize AFR laser channels histologically.