Ablative Fractional Laser Research Articles

Efficacy and safety of a topical skincare regimen containing CE Ferulic serum and resveratrol BE serum following ablative fractional CO2 laser treatment: A prospective, randomized, split-face, controlled trial.

Ablative fractional CO2 laser is widely used to address various skin problems, but the treatment often leads to adverse effects such as erythema, dyspigmentation, and extended recovery periods, negatively impacting patients' quality of life. This study aimed to evaluate the efficacy and safety of a topical skincare regimen containing both CE Ferulic serum and Resveratrol BE night serum following fractional CO2 laser treatment in Chinese population. In this randomized, investigator-blinded, split-face, controlled trial, individuals aged 18-65 undergoing ablative CO2 laser treatment were randomly assigned to apply CE Ferulic plus resveratrol BE serum (CEF-RBE) to either side of face and normal saline (NS) to the other, for 14 consecutive days. The primary endpoint was erythema index (EI) on day 14, with key secondary endpoints including scabbing detachment time, percentage changes in EI and melanin index (MI), skin hydration, transepidermal water loss, skin sebum content, oedema, and overall subject satisfaction. The study included 51 patients, of whom 29 (56.9%) were female, with a mean (SD) age of 29.8 (5.39) years. On day 14, the CEF-RBE side exhibited significantly lower EI than the NS side (308.9 vs. 325.3, p = 0.034). The median (IQR) time (days) for complete scabbing detachment at the CEF-RBE side was 6.0 (5.0-8.0) compared to 6.5 (5.0-9.0) at NS side (p = 0.018). Additionally, the CEF-RBE side showed a 7.4% decrease in MI from baseline to day 14, while the NS side experienced a 0.2% increase (Δ = -7.6%, p = 0.044). Throughout the 14-day follow-up, the CEF-RBE side consistently displayed higher skin hydration than the NS side. The study highlighted the benefits of incorporating CEF-RBE following laser treatment in reducing erythema and hyperpigmentation, promoting wound healing, and maintaining skin hydration, although limitations such as contamination and adherence issues should be considered.

Fractional Ablative Carbon Dioxide Laser versus Fractional Non-Ablative 1410 nm Diode Laser in the Treatment of Acne Scars: A Clinical and Immunohistochemical Study

Background: Effectively managing acne scars while minimizing consequences is still a challenging task. The primary determinant in selecting and continuing therapy for a specific device is stimulating collagen production and dermal remodeling with the fewest possible complications. Objective: To evaluate the clinical and immunohistochemical results of ablative fractional carbon dioxide (FCO2) laser versus fractional non-ablative diode laser for treating facial acne scars. Methods and Materials: Thirty patients with atrophic acne scars were included in a split-face comparative study. Right and left facial sides received three sessions of FCO2 and diode laser, respectively, at one-month intervals. One month after the third session, patients were evaluated using photographs, the Goodman and Baron qualitative and quantitative global scarring grading system, the investigator’s global assessment, and patient satisfaction. A sample was collected from the area that had been treated, and the tissue was examined using hematoxylin and eosin (H–E) staining and immunohistochemistry staining for collagen I. Results: Goodman and Baron global scores showed a statistically significant difference compared to baseline on both sides of the face. However, there was no statistically significant difference between the two treatment modalities. Biopsy specimens showed an increased deposition of collagen I by both laser devices, which was validated and described by immunohistochemistry staining. Conclusion: Both FCO2 and fractional non-ablative diode lasers proved their efficacy in treating different types of acne scars. For patients who are interested in no downtime and no complications, fractional non-ablative diode laser is recommended as an efficient alternative modality.

A regenerative approach for temporomandibular joint repair: An invitro and exvivo study.

Current clinical approaches to regenerate temporomandibular joint (TMJ) articulating cartilage defects only treat the symptoms (i.e. pain and dysfunction) and do not seek to restore joint integrity for long-term relief. Therefore, we investigated a novel self-assembling tissue-engineered cartilage to overcome this significant clinical issue for TMJ regenerative purposes. Examine the maturation of dynamic self-regenerating cartilage (dSRC) using auricular chondrocytes and evaluate a novel combinatorial approach with fractional laser treatment and dSRC implantation for TMJ cartilage repair. A suspension of 107 freshly harvested rabbit ear chondrocytes was cultured under a continuous reciprocating motion to form the dSRC. After 2, 4 and 8 weeks of culture, dSRC samples were stained with H&E, Safranin-O and Toluidine Blue. Immunohistochemistry (IHC) was performed for collagens type I and II. Channels (300-500 μm diameter and 1.2-1.5 mm depth) were created in six freshly harvested condyles using a fractional Erbium laser. Two groups were tested: dSRC in a laser-ablated lesion (experimental) and an empty laser-ablated channel (control). TMJ condyles were cultured for up to 8 weeks and analysed as described above. H&E staining showed a high cell density in dSRC compared to native cartilage. All dSRC groups demonstrated intense Safranin-O staining, indicating high glycosaminoglycan (GAG) production and intense Toluidine Blue staining showed high proteoglycan content. IHC confirmed that dSRC consisted predominantly of collagen type II. The experimental group showed improved cartilage repair at both time points compared to the empty channels. dSRC viability and successful matrix formation were demonstrated invitro. The combination of fractional laser ablation and dSRC implantation enhanced cartilage repair.

Increased susceptibility to ischemia causes exacerbated response to microinjuries in the cirrhotic liver.

Fractional laser ablation is a technique developed in dermatology to induce remodeling of skin scars by creating a dense pattern of microinjuries. Despite remarkable clinical results, this technique has yet to be tested for scars in other tissues. As a first step toward determining the suitability of this technique, we aimed to (1) characterize the response to microinjuries in the healthy and cirrhotic liver, and (2) determine the underlying cause for any differences in response. Healthy and cirrhotic rats were treated with a fractional laser then euthanized from 0 h up to 14 days after treatment. Differential expression was assessed using RNAseq with a difference-in-differences model. Spatial maps of tissue oxygenation were acquired with hyperspectral imaging and disruptions in blood supply were assessed with tomato lectin perfusion. Healthy rats showed little damage beyond the initial microinjury and healed completely by 7 days without scarring. In cirrhotic rats, hepatocytes surrounding microinjury sites died 4-6 h after ablation, resulting in enlarged and heterogeneous zones of cell death. Hepatocytes near blood vessels were spared, particularly near the highly vascularized septa. Gene sets related to ischemia and angiogenesis were enriched at 4 h. Laser-treated regions had reduced oxygen saturation and broadly disrupted perfusion of nodule microvasculature, which matched the zones of cell death. Our results demonstrate that the cirrhotic liver has an exacerbated response to microinjuries and increased susceptibility to ischemia from microvascular damage, likely related to the vascular derangements that occur during cirrhosis development. Modifications to the fractional laser tool, such as using a femtosecond laser or reducing the spot size, may be able to prevent large disruptions of perfusion and enable further development of a laser-induced microinjury treatment for cirrhosis.

88 Lessons Learned Evaluating Ablative Fractional CO2 Laser for Burn-Related Donor Site Scars

88 Lessons Learned Evaluating Ablative Fractional CO2 Laser for Burn-Related Donor Site Scars

527 Combination Treatment for Hypertrophic Burn Scars Utilizing Fractional Ablative and Continuous Wave CO2 Laser

527 Combination Treatment for Hypertrophic Burn Scars Utilizing Fractional Ablative and Continuous Wave CO2 Laser

The effect of combined red, blue, and near-infrared light-emitting diode (LED) photobiomodulation therapy on speed of wound healing after superficial ablative fractional resurfacing

Objective of the study is to assess the effects of wound healing with a commercially available light emitting diode (LED) photo biomodulation (PBM) device that emits three wavelengths (465, 640 and 880nm) after ablative fractional laser (AFL) treatment to healthy skin on the bilateral inner biceps. We conducted a prospective intraindividual randomized controlled study with 25 volunteers. AFL treatment was performed on healthy skin of the bilateral inner biceps. Subjects applied the LED light device for 30 min to the assigned bicep 3 times a week over 4 weeks, beginning on day 0. Subjects were followed up on days 2, 4, 6, 9, 13, 20 and 27 for treatment with the PBM device, clinical digital photography of the test and control sites, and in-person subject assessment, with follow ups on days 34 and 55 for clinical photography and assessment. Three blinded evaluators were asked to determine which bicep healed faster between day 0 to day 13. Pain, discomfort, and itch were also assessed. The three blinded evaluators chose the treatment arm as the faster healed arm in greater than 50% of the images, although the results were not statistically significant. There was no statistically significant difference between test and control arms in terms of pain, discomfort and itch. In conclusion, PBM therapy has the potential to improve wound healing. In this study, a three wavelength PBM device resulted in some subjects achieving faster healing after AFL but the results were not statistically significant.

Combining platelet rich plasma with ablative laser for post acne scars: A review.

Background Acne scars are one of the most common sequelae of inflammatory acne. It commonly affects adolescents and young adults and hence is associated with significant psychological morbidity. It is historically resistant to oral as well as surgical modalities. In the last two decades, ablative lasers (fractional or otherwise) have proven to be effective in management of acne scars. Some studies have proven the efficacy of platelet rich plasma in reducing the adverse effects and improving the efficacy of lasers. Objective Review of the studies combining platelet rich plasma with ablative laser for post acne scars. Methods A literature review of the MEDLINE database for studies evaluating the combination of ablative lasers with platelet rich plasma was performed. Only studies with higher levels of evidence (randomised controlled trials and comparative studies) were included in this review. Results Adding intradermal platelet rich plasma to fractional ablative lasers in the management of post acne scars increases clinical efficacy, reduces downtime as well as frequency and duration of ablative lasers related adverse effects. The efficacy of topical platelet rich plasma is less as compared to intradermal platelet rich plasma. Limitations The studies analysed are heterogeneous in nature with varied protocols and duration of follow up. Conclusions It is recommended to combine the ablative lasers with intradermal platelet rich plasma for better clinical response and reduce adverse effects as well as downtime.

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

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. 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. 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. 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.

Efficacy and safety of bipolar fractional radiofrequency vs. 2940-nm Er:YAG ablative fractional laser in striae distensae treatment: A split abdomen study.

Striae distensae (SD) is a challenging cosmetic condition. Ablative fractional laser (AFL) is an effective method for treating SD. Recently, fractional radiofrequency (FRF) has been shown to be a promising treatment for SD; however, few studies have shown the differences between FRF and AFL in the treatment of SD. This study aimed to evaluate and compare the clinical efficacy and safety of bipolar FRF with 2940-nm erbium yttrium aluminum garnet (Er:YAG) AFL in the treatment of SD. Twenty volunteers with abdominal SD were enrolled in this study. One half of the abdomen was treated with 2940-nm Er:YAG AFL, whereas the other half was treated with bipolar FRF, with three sessions at 4-week intervals. Photographic evaluations of clinical improvement were conducted by two independent investigators before and after treatment, and the patients provided self-assessments. Two participants underwent three punch biopsies, one before treatment and two obtained from bilateral representative skin lesions on the abdomen 3 months following the final treatment. Clinical improvements were observed in SD on both sides of the abdomen after the two treatments. Post-treatment skin biopsies revealed increased thickness in the epidermis and dermis, and higher collagen and elastin density compared to those at the baseline. No statistically significant differences were observed in the clinical outcomes between the two treatment approaches. The efficacy and safety of bipolar FRF treatment are comparable to those of 2940-nm Er:YAG AFL treatment, providing an alternative and effective treatment for SD.

Efficacy and Safety ofAblativeFractionalLaser in Melasma: A Meta-analysis and Systematic Review.

Melasma is a common acquired skin pigmentation disorder. The treatment is urgent but challenging. Ablative fractional laser (AFL) can improve pigmentation, but the efficacy and potential side effects are still debatable. This study aimed to evaluate the efficacy and safety of ablative fractional lasers in the treatment of melasma. A comprehensive systematic search of literature published before June 20, 2023, was conducted on online databases, including PubMed, Embase, Cochrane Library, and Web of Science. The data obtained were analyzed using Review Manager 5.4 software. Fourteen randomized controlled trials, comprising 527 patients, were included. Compared to the drug alone, the combination of AFL and the drug showed improved therapeutic efficacy in the melasma area and severity index (MASI) (MD = 1.54, 95% CI [0.16, 2.92], P = 0.03) and physician global assessment (RR = 1.61, 95% CI [1.08, 2.41], P = 0.02). However, no statistically significant results were found in patient self-assessment (RR = 1.56, 95% CI [0.88, 2.76], P = 0.12). As an individual therapy, AFL is not superior to any other lasers in terms of MASI (MD = 2.66, 95% CI [-1.32, 6.64], P = 0.19) or melanin index (MD = -7.06, 95% CI [-45.09, 30.97], P = 0.72). Common adverse events included transient erythema, burning, edema, and superficial crusting. Only a few patients experienced reversible post-inflammatory hyperpigmentation, herpes labialis, and acne breakouts. These results support the application of AFL as a viable treatment option for melasma, particularly in refractory and severe cases. Rational parameterization or combination therapy may lead to significant clinical improvement with fewer complications.

The role of laser and energy-assisted drug delivery in the treatment of alopecia.

It has been recently established that laser treatment can be combined with topical or intralesional medications to enhance the delivery of drugs and improve overall results in a variety of different dermatological disorders. The aim of this review is to evaluate the use of laser and energy-assisted drug delivery (LEADD) for the treatment of alopecia with a specific focus on ablative fractional lasers (AFL), non-ablative fractional lasers (NAFL), and radiofrequency microneedling (RFMN). A comprehensive PubMed search was performed in December 2022 for "laser-assisted drug delivery" as well as "laser" and "alopecia." The evidence regarding LEADD for alopecia treatment is limited to two specific alopecia subtypes: alopecia areata (AA) and androgenetic alopecia (AGA)/pattern hair loss (PHL). LEADD with minoxidil and platelet-rich plasma (PRP) were evaluated for efficacy in both treatments of AA and AGA. LEADD with topical corticosteroids and intralesional methotrexate were studied for the treatment of AA, while LEADD with growth factors and stem cells were studied for the treatment of AGA. Multiple RCTs evaluated LEADD for topical corticosteroids with ablative fractional lasers for the treatment of AA. There is evidence in the literature that supports the use of topical minoxidil in combination with all devices for the treatment of AGA/PHL. All the reviewed studies show a positive treatment effect with LADD; however, some trials did not find LEADD to be superior to monotherapy or microneedling-assisted drug delivery. LEADD is a rapidly emerging treatment modality for the treatment of AGA and AA.

Full-face and neck resurfacing with a novel ablative fractional 2910 nm erbium-doped fluoride glass fiber laser for advanced photoaging.

Ablative fractional lasers have long been considered the gold standard for facial resurfacing for advanced photoaging. These lasers offer an improved safety profile compared to traditional ablative lasers but typically require more treatment sessions given their fractional approach. In this study, we evaluate a new novel 2910 nm erbium-doped fluoride glass fiber laser (2910 nm fiber laser) (UltraClear; Acclaro Medical) for full-face and neck resurfacing for the treatment of advanced photoaging. Twenty-two healthy subjects aged 44-80 years presenting for advanced facial photoaging and rhytides were enrolled in the study. All subjects received three full-face and neck, multipass treatments utilizing the 2910 nm fiber laser spaced 6-8 weeks apart. Subjects were asked to rate the average level of pain during the treatment. At 90 days following subjects' third treatment subjects evaluated their improvement using a Global Aesthetic Improvement Scale (GAIS) and rated their satisfaction with the treatment. Evaluation of pretreatment and posttreatment photos was completed by two blinded physician reviewers. Reviewers were asked to identify the pretreatment and posttreatment photographs and to rate the degree of improvement utilizing a GAIS. Fifteen participants completed the study; six were exited from the study (withdrew or lost to follow-up). The average subject GAIS score for overall appearance was 3.8. The average subject satisfaction level at follow-up was 4.8. The average subject pain score was 4.9. One blinded physician reviewer correctly identified 100% of subjects' posttreatment photographs, while the second blinded reviewer correctly identified 93%. Blinded evaluation of digital photographs revealed an average GAIS score of 3.2. Posttreatment skin responses included pin-point hemorrhage, erythema, edema, and soft tissue crusting lasting 5-7 days. There were no instances of infection, scarring or hypopigmentation. There were two instances of temporary hyperpigmentation. Treatment with the novel 2910 nm fiber laser is safe and effective in treating advanced photoaging and rhytides. Three treatments produced moderate to marked improvement with high patient satisfaction and treatment was associated with less discomfort and downtime compared to conventional fractional ablative lasers.

Laser-Assisted Drug Delivery in the Treatment of Hypertrophic Scars and Keloids: A Systematic Review.

Hypertrophic scars and keloids are the results of an exaggerated healing process and are often associated with significant patient morbidity. Fractional ablative lasers create microchannels in the skin and penetrate into the substance of the scar, inducing a normal healing response in zones of created damage. Focal delivery of scar-modulating agents into the scar through these microchannels-a process termed laser-assisted drug delivery (LADD)-is a promising and developing treatment modality. In this systematic review, we aim to critically examine the evidence of LADD in the treatment of hypertrophic scars and keloids. The evidence suggests that LADD improves outcomes in hypertrophic scars and keloids. LADD is a more effective treatment modality than the topical application of agents in hypertrophic scars and equally effective as the intralesional injection of agents in keloids. There were few reports of adverse events. Evidence supports the use of LADD as an adjunct to non-surgical measures or a treatment modality to be used before more invasive measures such as surgical excision. However, the quality of evidence supporting this conclusion is inconsistent and lacks power. Additional studies are required to optimize dosages, laser settings, and agent choices for the treatment of these lesions.

The role of fractional laser-assisted drug delivery in enhancing the efficacy of topical bimatoprost solution in the treatment of alopecia areata: An intra-patient comparative randomized clinical trial.

Transepidermal drug delivery is a novel therapeutic technique to boost efficacy of topical drugs. In this clinical trial we evaluate the efficacy of the combination of fractional carbon dioxide (FCO2) laser and bimatoprost solution compared to bimatoprost alone in the treatment of alopecia areata. This is a prospective intra-patient comparative randomized clinical trial on 20 patients with alopecia areata. In each participant two patches were chosen to randomly receive either topical 0.03% bimatoprost solution (twice a day for 12 weeks) alone or in combination with FCO2 laser (every 2 weeks for 12 weeks). Then response to treatment was evaluated by the measurement of the severity of alopecia tool score system (SALT) score, percentage of hair regrowth, physician assessment and patients' satisfaction. SALT score was reduced significantly during treatment sessions and after a 3-month follow-up in both treatment groups (p = 0.000). The mean percentage of improvement in SALT score in the combination therapy and monotherapy groups were 46.43 ± 4.35% and 21.16 ± 4.06% at the end of the study and 46.42 ± 5.75% and16.11 ± 3.10% at the end of the follow-up period, respectively (p = 0.000). A general linear model of two-way analysis demonstrated a significantly superior outcome in the combination therapy group compared to the monotherapy group during time (F1.6, 13.2 = 43.8. p = 0.000). Fractional ablative laser can be considered as an assistant method for enhancing of efficacy of topical drugs especially in refractory cases of patchy alopecia areata.

Laser-assisted topical delivery of vismodegib reduces hedgehog gene expression in human basal cell carcinomas in vivo.

Systemically delivered hedgehog inhibitors including vismodegib and sonidegib are widely used to treat basal cell carcinomas (BCCs). Ablative fractional laser (AFL)-assisted topical delivery of vismodegib has been demonstrated in preclinical studies. The aim of this explorative clinical study was to evaluate intratumoral vismodegib concentrations and effect on hedgehog pathway gene expression following AFL-assisted topical vismodegib delivery to BCCs. In an open-label clinical trial, 16 nodular BCCs (in n = 9 patients) received one application of CO2 -AFL (40 mJ/microbeam, 10% density) followed by topical vismodegib emulsion. After 3-4 days, vismodegib concentrations in tumor biopsies (n = 15) and plasma were analyzed and compared with samples from patients receiving oral treatment (n = 3). GLI1, GLI2, PTCH1, and PTCH2 expression was determined by quantitative polymerase chain reaction (n = 7) and GLI1 additionally by in situ hybridization (n = 3). Following AFL-assisted topical administration, vismodegib was detected in 14/15 BCCs and reached a median concentration of 6.2 µmol/L, which compared to concentrations in BCC tissue from patients receiving oral vismodegib (9.5 µmol/L, n = 3, p = 0.8588). Topical vismodegib reduced intratumoral GLI1 expression by 51%, GLI2 by 55%, PTCH1 and PTCH2 each by 73% (p ≤ 0.0304) regardless of vismodegib concentrations (p ≥ 0.3164). In situ hybridization demonstrated that GLI1 expression was restricted to tumor tissue and downregulated in response to vismodegib exposure. A single AFL-assisted topical application of vismodegib resulted in clinically relevant intratumoral drug concentrations and significant reductions in hedgehog pathway gene expressions.

Ablative fractional laser treatment reduces hedgehog pathway gene expression in murine basal cell carcinomas

This study aimed to investigate the impact of ablative fractional laser (AFL) on hedgehog pathway gene expression in murine microscopic basal cell carcinomas (BCCs) and compare these results to the effect of topical treatment with vismodegib, an FDA-approved hedgehog inhibitor. In 25 mice, 1 cm2 skin test sites (n = 44) containing microscopic BCCs were exposed to one of three interventions: a single CO2 AFL treatment (1 pulse, 40 mJ/microbeam, wavelength 10.6 μm, 5% density, pulse rate 250 Hz, n = 12), eight topical vismodegib treatments (3.8 mg/mL, n = 8), or combination of AFL and vismodegib treatments (n = 9). Untreated controls were included for comparison (n = 15). After 4 days, skin samples were analyzed for hedgehog gene expression (Gli1, Gli2, and Ptch1) by qPCR and vismodegib concentrations by liquid chromatography mass spectrometry (data analyzed with two-tailed t-tests and linear regression). A single treatment with AFL monotherapy significantly reduced hedgehog gene expression compared to untreated controls (Gli1 72.4% reduction, p = 0.003; Gli2 55.2%, p = 0.010; Ptch1 70.9%, p < 0.001). Vismodegib treatment also reduced hedgehog gene expression (Gli1 91.6%; Gli2 83.3%; Ptch1 83.0%), significantly surpassing AFL monotherapy for two out of three genes (Gli1, p = 0.017; Gli2, p = 0.007; Ptch1, p = 0.15). AFL and vismodegib combination mirrored the effects of vismodegib monotherapy (Gli1, p = 0.424; Gli2, p = 0.289; Ptch1, p = 0.593), possibly due to comparable cutaneous vismodegib concentrations (mean ± SD, vismodegib monotherapy 850 ± 475 µmol/L; combination 1036 ± 824 µmol/L; p = 0.573). In conclusion, a single AFL treatment significantly reduced hedgehog gene expression in murine BCCs mimicking the effects of eight topical applications of vismodegib. Further studies are needed to assess whether AFL can be utilized for BCC treatment, either as monotherapy or in combination with other drugs.

Anti-PD-1 immunotherapy with adjuvant ablative fractional laser displays increased tumour clearance of squamous cell carcinoma, a murine study.

PD-1 checkpoint inhibitors are used as systemic immunotherapy for locally advanced and metastatic cutaneous squamous cell carcinoma (SCC); however, improved treatment efficacy is urgently needed. In this study, we aimed to investigate the effect of combining systemic anti-PD-1 treatment with adjuvant ablative fractional laser (AFL) in a spontaneous SCC mouse model. Tumours induced by ultraviolet radiation in the strain C3.Cg-Hrhr /TifBomTac were divided into four groups: anti-PD-1-antibody+AFL (n = 33), AFL alone (n = 22) anti-PD-1-antibody alone (n = 31) and untreated controls (n = 46). AFL was given at Day 0 (100 mJ/mb, 5% density), while anti-PD-1-antibody (ip, 200 μg) at Days 0, 2, 4, 6 and 8. Response to treatment was evaluated by tumour growth, survival time and by dividing response to treatment into complete responders (clinically cleared tumours), partial responders (reduced tumour growth rate compared to untreated controls) and non-responders (no decrease in tumour growth rate compared to untreated controls). The strongest tumour response was observed following the combination of systemic anti-PD-1 treatment combined with laser exposure, resulting in the highest percentage of complete responders (24%) compared with untreated controls (0%, p < 0.01), AFL monotherapy (13%, p > 0.05) and anti-PD-1-antibody monotherapy (3%, p > 0.05). Moreover, all three treatment interventions demonstrated significantly reduced tumour growth rates compared with untreated controls (p < 0.01), and the mice had significantly longer survival times (p < 0.01). In conclusion, the combination treatment revealed an improved treatment effect that significantly enhanced the complete tumour clearance not observed with the monotherapies, indicating a possible additive effect of anti-PD-1 with adjuvant AFL in treatment of SCC.

Novel 40 µm spot size 3050/3200 nm DFG laser versus CO2 laser for laser-assisted drug delivery.

The use of ablative fractional lasers to enhance the delivery of topical drugs through the skin is known as laser-assisted drug delivery. Here, we compare a novel 3050/3200 nm difference frequency generation (DFG) fiber laser (spot size: 40 µm) to a commercially used CO2 laser (spot size: 120 µm). The objective is to determine whether differences in spot size and coagulation zone (CZ) thickness influence drug uptake. Fractional ablation was performed on ex-vivo human abdominal skin with the DFG (5 mJ) and CO2 (12 mJ) lasers to generate 680 µm deep lesions. To evaluate drug delivery, 30 kDa encapsulated fluorescent dye was topically applied to the skin and histologically analyzed at skin depths of 100, 140, 200, 400, and 600 µm. Additionally, transcutaneous permeation of encapsulated and 350 Da nonencapsulated dye was assessed using Franz Cells. The DFG laser generated smaller channels (diameter: 56.5 µm) with thinner CZs (thickness: 22.4 µm) than the CO2 laser (diameter: 75.9 µm, thickness: 66.8 µm). The DFG laser treated group exhibited significantly higher encapsulated dye total fluorescence intensities after 3 h compared to the CO2 laser treated group across all skin depths (p < 0.001). Permeation of nonencapsulated dye was also higher in the DFG laser treated group vs the CO2 laser treated group after 48 h (p < 0.0001), while encapsulated dye was not detected in any group. The DFG laser treated skin exhibited significantly higher total fluorescence uptake compared to the CO2 laser. Additionally, the smaller spot size and thinner CZ of the DFG laser could result in faster wound healing and reduced adverse effects while delivering similar or greater amount of topically applied drugs.

Treatment of hypopigmented burn hypertrophic scars with short-term topical tacrolimus does not lead to repigmentation.

Dyschromia is an understudied aspect of hypertrophic scar (HTS). The use of topical tacrolimus has successfully shown repigmentation in vitiligo patients through promotion of melanogenesis and melanocyte proliferation. It was hypothesized that HTSs treated with topical tacrolimus would have increased repigmentation compared to controls. Full-thickness burns in red Duroc pigs were either treated with excision and meshed split-thickness skin grafting or excision and no grafting, and these wounds formed hypopigmented HTSs (n = 8). Half of the scars had 0.1% tacrolimus ointment applied to the scar twice a day for 21 days, while controls had no treatment. Further, each scar was bisected with half incurring fractional ablative CO2 laser treatment before topical tacrolimus application to induce laser-assisted drug delivery (LADD). Pigmentation was evaluated using a noninvasive probe to measure melanin index (MI) at Days 0 (pretreatment), 7, 14, and 21. At each timepoint, punch biopsies were obtained and fixed in formalin or were incubated in dispase. The formalin-fixed biopsies were used to evaluate melanin levels by H&E staining. The biopsies incubated in dispase were used to obtain epidermal sheets. The ESs were then flash frozen and RNA was isolated from them and used in quantitative reverse transcription polymerase chain reaction for melanogenesis-related genes: Tyrosinase (TYR), TYR-related protein-1 (TYRP1), and dopachrome tautomerase (DCT). Analysis of variance test with Šídák's multiple comparisons test was used to compare groups. Over time, within the grafted HTS and the NS group, there were no significant changes in MI, except for Week 3 in the -Tacro group. (+Tacro HTS= pre = 685.1 ± 42.0, w1 = 741.0 ± 54.16, w2 = 750.8 ± 59.0, w3 = 760.9 ± 49.8) (-Tacro HTS= pre = 700.4 ± 54.3, w1 = 722.3 ± 50.7, w2 = 739.6 ± 53.2, w3 = 722.7 ± 50.5). Over time, within the ungrafted HTS and the NS group, there were no significant changes in MI. (+Tacro HTS= pre = 644.9 ± 6.9, w1 = 661.6 ± 3.3, w2 = 650.3 ± 6.2, w3 = 636.3 ± 7.4) (-Tacro HTS= pre = 696.8 ± 8.0, w1 = 695.8 ± 12.3, w2 = 678.9 ± 14.0, w3 = 731.2 ± 50.3). LADD did not lead to any differential change in pigmentation compared to the non-LADD group. There was no evidence of increased melanogenesis within the tissue punch biopsies at any timepoint. There were no changes in TYR, TYRP1, or DCT gene expression after treatment. Hypopigmented HTSs treated with 0.1% tacrolimus ointment with or without LADD did not show significantly increased repigmentation. This study was limited by a shorter treatment interval than what is known to be required in vitiligo patients for repigmentation. The use of noninvasive, topical treatments to promote repigmentation are an appealing strategy to relieve morbidity associated with dyschromic burn scars and requires further investigation.