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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSION

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 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.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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.

Impact of skin hydration on patterns of microthermal injury produced by fractional CO2 laser

OBJECTIVES

The impact of skin hydration on patterns of thermal injury produced by ablative fractional lasers (AFLs) is insufficiently examined under standardized conditions. Using skin with three different hydration levels, this study assessed the effect of hydration status on microchannel dimensions generated by a fractional CO2 laser.

METHODS

A hydration model (hyperhydrated-, dehydrated- and control) was established in ex vivo porcine skin, validated by changes in surface conductance and sample mass. After, samples underwent AFL exposure using a CO2 laser (10,600 nm) at two examined pulse energies (10 and 30 mJ/mb, fixed 10% density, six repetitions per group). Histological assessment of distinct microchannels (n = 60) determined three standardized endpoints in H&E sections: (1) depth of microthermal treatment zones (MTZs), (2) depth of microscopic ablation zones (MAZs), and (3) coagulation zone (CZ) thickness. As a supplemental in vivo assessment, the same laser settings were applied to hyperhydrated- (7-h occlusion) and normohydrated forearm skin (no pretreatment) of a human volunteer. Blinded measurement of MAZ depth (n = 30) was performed using noninvasive optical coherence tomography (OCT).

RESULTS

Modest differences in microchannel dimensions were shown between hyperhydrated, dehydrated and control skin at both high and low pulse energy. Compared to controls, hyperhydration led to median reductions in MTZ and MAZ depth ranging from 5% to 8% (control vs. hyperhydrated at 30 mJ/mb; 848 vs. 797 µm (p < 0.003) (MAZ); 928 vs. 856 µm (p < 0.003) (MTZ)), while 14%-16% reductions were shown in dehydrated skin (control vs. dehydrated at 30 mJ/mb; MAZ: 848 vs. 727 µm (p < 0.003); MTZ: 928 vs. 782 µm (p < 0.003)). The impact of skin hydration on CZ thickness was in contrast limited. Corresponding with ex vivo findings, hyperhydration was similarly associated with lower ablative depth in vivo skin. Thus, median MAZ depth in hydrated skin was 10% and 14% lower than in control areas at 10 and 30 mJ/mb pulse energy, respectively (10 mJ: 210 vs. 180 µm (p < 0.001); 30 mJ: 335 vs. 300 µm (p < 0.001)).

CONCLUSION

Skin hydration status can exert a minimal impact on patterns of microthermal injury produced by fractional CO2 lasers, although the clinical implication in the context of laser therapy requires further study.

In vivo characterization of laser-assisted delivery of hyaluronic acid using multiphoton fluorescence lifetime imaging

Laser-assisted drug delivery (LADD) is a treatment method to enhance the penetration of pharmaceuticals through the skin. The aim of the present study is to track hyaluronic acid (HA) and analyse its effect on human skin in vivo after ablative fractional laser (AFL) treatment. Healthy male and female subjects were recruited. Four areas were marked on their forearms of each volunteer, and each area was assigned to one of the following treatment options: AFL + HA, AFL only, HA only or untreated control. A carbon dioxide laser was used for the AFL treatment. Follow-up measurements were scheduled 30 min and 30 days after treatment using multiphoton tomography equipped with fluorescence lifetime imaging (MPT-FLIM). A total of 11 subjects completed the study. By detecting fluorescence lifetimes, the HA and the anaesthetic ointment were clearly distinguishable from surrounding tissue. After AFL treatment, HA could be visualized in all epidermal and upper dermal layers. In contrast, HA in intact skin was only detected in the superficial layers at distinctly lower levels. The applied HA gel seemed to have beneficial properties for the wound healing process after laser treatment. LADD has proven to be a fast and effective method to increase HA uptake into the skin, allowing for improved hydration and skin rejuvenation over time. Furthermore, LADD could be a beneficial treatment option in laser resurfacing. MPT-FLIM proved to be an appropriate diagnostic tool for drug delivery tracking and monitoring of treatment response for individualized therapy adjustment.

Combination of Fractional Microneedling Radiofrequency and Ablative Fractional Laser versus Ablative Fractional Laser Alone for Acne and Acne Scars

PURPOSE

Fractional microneedle radiofrequency (FMR) systems are used to treat inflammatory acne and scarring. Nonetheless, few controlled studies have combined this treatment with the traditional ablative fractional laser (AFL). We aimed to assess the safety and efficacy of the combination of FMR and AFL versus AFL alone in treating acne and acne scars.

MATERIALS AND METHODS

In this 20-week, randomized, split-face study, 23 Korean patients with facial acne and acne scars underwent FMR and AFL treatments. One half of each patient's face was randomly assigned to receive FMR+AFL, whereas the other half received AFL alone. Treatments were administered in three consecutive sessions at 4-week intervals. This study investigated the severity of inflammatory acne, acne scars, individual lesion counts, depressed scar volumes, as well as patient and physician satisfaction. In addition, five patients underwent skin biopsy, and sebum output was measured.

RESULTS

The FMR+AFL treatment demonstrated superior efficacy compared to AFL alone in terms of inflammatory acne and acne scar grading, lesion counts, and subjective satisfaction. The side effects were minimal and well-tolerated in both groups. Immunohistochemical findings from skin biopsy samples revealed that the application of FMR+AFL could induce an inhibitory effect on sebum secretion at the molecular level.

CONCLUSION

FMR combined with AFL is a well-tolerated and effective treatment modality for inflammatory acne and acne scarring.

Repeated exposure to fractional CO2 laser delays squamous cell carcinoma formation and prevents clinical and subclinical photodamage visualized by line-field confocal optical coherence tomography and histology

OBJECTIVES

Ablative fractional laser (AFL) is a well-established modality for treating ultraviolet radiation (UVR)-induced skin photodamage. We aimed to investigate the potential of AFL to delay squamous cell carcinoma (SCC) formation and prevent photodamage in a preclinical UVR-induced SCC model.

MATERIALS AND METHODS

Hairless C3.Cg-Hrhr /TifBomTac mice (n = 50) were exposed to UVR three times weekly throughout the study. UV-exposed mice were randomized to two groups that received dorsal CO2 AFL (10 mJ/mb, 10% density) or no treatment. AFL was performed every other week for a total of 16 weeks (nine treatments in total). The primary outcome was time to tumor occurrence. In a subset of mice on Day 150, prevention of clinical photodamage was assessed by examination of skin tightness and dyspigmentation. Concomitantly, assessment of subclinical photoprevention based on normalization of keratinocyte dysplasia, dermo-fiber morphology (collagen and elastin fibers), and skin thickness, was performed using line-field confocal optical coherence tomography (LC-OCT) and histology.

RESULTS

Repeated AFL treatments delayed SCC tumor development compared to UVR control mice by 12, 19, and 30 days for first, second, and third tumors, respectively (p ≤ 0.0017). Compared to UVR controls, AFL prevented photodamage both clinically and subclinically, based on LC-OCT and histology. In the epidermal layer, AFL imparted photopreventative effects including reduced dyspigmentation and keratinocyte dysplasia (1 vs. 2.5, p = 0.0079) and partial normalization of the epidermal thickness (p < 0.0001). In the dermis, AFL led to twofold greater skin tightness (p = 0.0079), improved dermo-fiber structure, and dermal thickness (p = 0.0011).

CONCLUSION

In conclusion, repeated AFL treatments of UVR-exposed skin significantly delayed SCC tumor formation and prevented clinical and imaging-assessed subclinical signs of photodamage, indicating a potential for AFL in prevention strategies for SCC and photodamage in high-risk populations.

Combined use of energy-based interventions with low-dose isotretinoin for the treatment of inflammatory acne: An retrospective cohort analysis

BACKGROUND

The combined use of oral isotretinoin with energy-based interventions including fractional microneedle radiofrequency, pulsed dye laser, and ablative fractional laser is an effective way to treat moderate-to-severe inflammatory acne lesions. However, studies regarding its efficacy and safety are limited.

AIMS

This study aimed to assess the efficacy and safety of a treatment using low-dose isotretinoin with energy-based interventions for inflammatory acne.

PATIENTS AND METHODS

This retrospective cohort study included 126 patients who were diagnosed with inflammatory acne and were treated with systemic isotretinoin for at least 3 months. Patients were divided into EBD (energy-based intervention) (n=82) and non-EBD groups (n=44). Clinical outcomes of both groups were assessed using medical records and digital photographs.

RESULTS

After treatment, the modified Global Acne Grading Score of the EBD and non-EBD groups decreased by 35.1±17.2 and 25.6±10.1, respectively. The improvement in acne severity was significantly greater in the EBD group than in the non-EBD group. Cumulated isotretinoin dose and frequency of drug-related side effects were significantly higher in the non-EBD group than in the EBD group.

CONCLUSION

Combined treatment with low-dose isotretinoin and energy-based intervention is well tolerated and associated with positive responses in patients with inflammatory acne.

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.

Topical delivery of PD-1 inhibitors with laser-assisted passive diffusion and active intradermal injection: Investigation of cutaneous pharmacokinetics and biodistribution patterns

BACKGROUND AND OBJECTIVES

Current cancer immunotherapeutic treatment with PD-1 inhibitors is administered systemically. However, a local treatment strategy may be advantageous as it could provide targeted drug delivery as well as attenuate side effects seen with systemic treatments. For keratinocyte cancers, where surgical excision is not always applicable, an alternate local treatment approach would be beneficial. This study aims to examine cutaneous pharmacokinetics and biodistribution of the PD-1 inhibitor nivolumab, locally delivered either by ablative fractional laser (AFL)-assisted passive diffusion or active intradermal injection, in vivo.

MATERIALS AND METHODS

In vivo pig skin was either exposed to CO₂ AFL (80 mJ/mb by two stacked pulses of 40 mJ/mb) at 5% or 15% density followed by topical application of nivolumab (1 mg/ml, 100 µl/10 × 10 mm) or intradermally injected with nivolumab (1 mg/ml, 100 µl). Cutaneous nivolumab delivery was evaluated at different timepoints (0, 1, 2, 4 hours and 2 days) at two tissue depths (100-800 and 900-1600 µm) by ELISA. Visualization of cutaneous biodistribution was shown in vertical tissue sections using HiLyte Fluor^TM 488 SE labeled nivolumab for fluorescence microscopy whereas nivolumab was DOTA-tagged with Dysprosium before the laser ablation-inductively coupled plasma-mass spectrometry analysis (LA-ICP-MS).

RESULTS

Our in vivo study revealed different pharmacokinetic and biodistribution patterns for the AFL- and injection techniques. A superficial horizontal band-like uptake of nivolumab was provided with AFL-assisted passive diffusion whereas a deep focal deposition was seen with active intradermal injection, compared with controls showing remnant deposition on the skin surface. AFL-assisted nivolumab uptake in upper dermis peaked after 4 hours (p < 0.01). The cutaneous concentration of nivolumab achieved by intradermal injection was markedly higher than with AFL, the highest deposition with intradermal injection was detected at time 0 hours in both upper and deep dermis (p < 0.01) and decreased throughout the study period, although the concentration remained higher compared with saline control injections at all time points (0 hours -2 d) (p < 0.01).

CONCLUSION

Local cutaneous delivery of nivolumab with either AFL or intradermal injection revealed two different pharmacokinetic and biodistribution patterns. Passive AFL-assisted diffusion of nivolumab resulted in enhanced uptake after 4 hours, while intradermal actively injected nivolumab showed immediate enhanced cutaneous deposition with retention up to 2 days after injection. The two local delivery techniques show potential for development of individualized treatment strategies depending on the clinical tumor appearance.

HeaLED: Assessment of skin healing under light-emitting diode (LED) exposure-A randomized controlled study versus placebo

BACKGROUND

Light-emitting diodes (LEDs) in the visible or near-infrared spectrum have been reported to promote wound healing. However, despite being frequently proposed in daily clinical practice, the efficacy of photobiomodulation treatment after a laser procedure relies on very limited clinical data.

OBJECTIVE

To compare the relative efficacy of LED versus placebo treatment in decreasing erythema and transepidermal water loss (TEWL) after a fractional CO₂ session.

METHODS

We conducted an open prospective intraindividual randomized controlled study with 10 healthy volunteers. An ablative fractional laser was performed on the seven forearm areas. Three consecutive daily sessions of LED (590, 630, and 850 nm [two tested irradiances each] and placebo) were applied after randomization. Physical measures (colorimetry, TEWL), photography, and clinical evaluation were performed on Days 1, 2, 3, 7, and 21. The main criterion of evaluation was the variation of parameter a* (erythema) at 72 hours for each LED parameter compared to placebo treatment.

RESULTS

No significant differences in the variation of the parameter a* or any of the other studied parameters were found for the different LEDs compared to the placebo area.

CONCLUSION

Photobiomodulation failed to improve healing after laser ablation compared to placebo.

ablative fractional laser for oral leukoplakia treatment: A randomized, controlled pilot study

BACKGROUND

Ablative fractional laser-assisted photodynamic therapy (AFL-PDT) is explored as an effective method in some premalignant diseases, whereas the effect of AFL-PDT on oral leukoplakia (OL), the best-known precursor of oral squamous cell carcinoma, remains undetermined.

METHODS

Forty-eight patients, histologically diagnosed with OL, were randomized (1:1) to receive either AFL-PDT or ablative fractional laser (AFL) treatment. All patients were followed up at 1, 3, 6 and 12 months postoperatively. The primary endpoints of efficacy and clinical recurrence and the secondary endpoint of side effects were assessed.

RESULTS

Forty-four patients completed the study. The 100% effective cure rate in the AFL-PDT group was higher than that in AFL group (80.9%, P<0.05) with 19.1% difference (95%CI: 0.7-40.0%). Compared to AFL group, recurrence observed at 6 and 12 months post-treatment tended to occur in fewer patients in the AFL-PDT group (P<0.05). No severe adverse events or systemic side effects were observed in either group.

CONCLUSIONS

AFL-PDT may effectively reduce recurrence of OL with high clinical efficacy and good tolerability, suggesting it may be a promising treatment for OL.

Bleomycin administered by laser-assisted drug delivery or intradermal needle-injection results in distinct biodistribution patterns in skin: in vivo investigations with mass spectrometry imaging

Bleomycin (BLM) is being repositioned in dermato-oncology for intralesional and intra-tumoural use. Although conventionally administered by local needle injections (NIs), ablative fractional lasers (AFLs) can facilitate topical BLM delivery. Adding local electroporation (EP) can augment intracellular uptake in the target tissue. Here, we characterize and compare BLM biodistribution patterns, cutaneous pharmacokinetic profiles, and tolerability in an in vivo pig model following fractional laser-assisted topical drug delivery and intradermal NI, with and without subsequent EP. In vivo pig skin was treated with AFL and topical BLM or NI with BLM, alone or with additional EP, and followed for 1, 2 and 4 h and eventually up to 9 d. BLM biodistribution was assessed by spatiotemporal mass spectrometry imaging. Cutaneous pharmacokinetics were assessed by mass spectrometry quantification and temporal imaging. Tolerability was evaluated by local skin reactions (LSRs) and skin integrity measurements. AFL and NI resulted in distinct BLM biodistributions: AFL resulted in a horizontal belt-shaped BLM distribution along the skin surface, and NI resulted in BLM radiating from the injection site. Cutaneous pharmacokinetic analyses and temporal imaging showed a substantial reduction in BLM concentration within the first few hours following administration. LSRs were tolerable overall, and all interventions permitted almost complete recovery of skin integrity within 9 d. In conclusion, AFL and NI result in distinct cutaneous biodistribution patterns and pharmacokinetic profiles for BLM applied to in vivo skin. Evaluation of LSRs showed that both methods were similarly tolerable, and each method has potential for individualized approaches in a clinical setting.

Tumor Clearance and Immune Cell Recruitment in UV-Induced Murine Squamous Cell Carcinoma Exposed to Ablative Fractional Laser and Imiquimod Treatment

BACKGROUND AND OBJECTIVES

Keratinocyte carcinoma (KC) is the most common cancer worldwide, and squamous cell carcinoma (SCC) is the second most frequent subtype. Ablative fractional laser (AFL)-assisted drug delivery significantly enhances the uptake of topically applied drugs. The objective of this study was to assess tumor response and perform a descriptive characterization of the local recruitment of immune cells and systemic immune mediator levels in an ultraviolet radiation (UVR)-induced murine SCC model after AFL treatment alone and combined with topical imiquimod.

STUDY DESIGN/MATERIALS AND METHODS

Immunocompetent hairless mice (C3·Cg/TifBomTac, n = 74) were irradiated with solar-simulated UVR until 3-mm SCCs developed. The mice were divided into four interventional groups: AFL alone, AFL + imiquimod, imiquimod alone, and untreated SCC controls. AFL was given as a single treatment, whereas imiquimod was applied daily until the mice were euthanized on Days 0, 2, 7, or 14. SCCs were photographed and measured (mm) to assess the therapeutic response. Skin samples were processed for histopathological and immunohistochemical analyses, as well as for flow cytometry. Cytokine expression changes in sera were analyzed using ELISpot cytokine arrays.

RESULTS

Treatment of mouse SCCs with AFL + imiquimod induced the most robust immune cell infiltration and the greatest proportion of tumor clearance compared to other interventions. Early innate immune cell infiltration was induced by AFL + imiquimod treatment as the number of neutrophils and macrophages had increased fourfold within 2 days of treatment initiation compared with untreated SCC control mice (P < 0.05). AFL treatment alone had a more limited effect, with a fourfold increase in neutrophils (P < 0.05) but no significant increase in the number of macrophages. Correspondingly, treatment with AFL + imiquimod had the greatest effects on the adaptive immune cell recruitment: CD4⁺ T-helper cells increased threefold at Day 7 compared with untreated SCCs (P = 0.0001) and, notably, cytotoxic CD8⁺ T cells increased 14-fold at Day 14 (P = 0.0112). In addition, FOXP3⁺ regulatory T cells (Tregs) increased 14-fold at Day 7 (P = 0.0026), suggesting the resolution of the inflammatory infiltration. AFL treatment alone induced a moderate immune cell infiltration (a twofold increase in CD4⁺ T-helper cells, P = 0.0200; a threefold increase in CD8⁺ T cells, P = 0.0100; and a 14-fold increase in FOXP3⁺ Tregs at Day 14, P = 0.0021), whereas imiquimod alone did not significantly increase cell counts. AFL + imiquimod treatment increased CXCL12 serum levels threefold at Day 14 (P = 0.0200).

CONCLUSION

AFL treatment alone and in combination with imiquimod induces substantial tumor clearance associated with local recruitment of innate and adaptive immune cells in UVR-induced murine SCCs. These results may provide a basis for new immunotherapeutic approaches to KC treatment.

Topical Delivery of Nivolumab, a Therapeutic Antibody, by Fractional Laser and Pneumatic Injection

BACKGROUND AND OBJECTIVES

PD-L1 is a tumor ligand that binds to the PD-1 receptor on immune cells, thereby inhibiting the antitumor immune response. The antibody nivolumab is a PD-1 inhibitor, Food and Drug Administration approved for systemic treatment of several aggressive cancer types. Topically applied nivolumab may hold potential as a future strategy to treat keratinocyte cancer, but its molecular properties preclude unassisted topical uptake. The aim of this study was to investigate uptake and biodistribution of topically delivered nivolumab, assisted by two physical enhancement techniques with different delivery kinetics; ablative fractional laser (AFL) and electronically controlled pneumatic injection (EPI).

STUDY DESIGN/MATERIALS AND METHODS

In vitro porcine skin was exposed to CO₂ AFL (20 mJ/mb, 5% density), followed by passive diffusion of nivolumab in a Franz cell (1 mg/ml, 18 hours, n = 6) or treated with EPI (4 bar) for immediate delivery of nivolumab (1 mg/ml, 10 minutes, n = 6). The resulting nivolumab skin concentrations were quantified by enzyme-linked immunosorbent assay (ELISA) at three skin depths (100, 500, and 1500 µm), comparing the uptake from assisted delivery with intact skin. Biodistribution of nivolumab in the skin for all interventions was visualized by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and fluorescence microscopy.

RESULTS

Delivery of nivolumab by AFL-assisted passive diffusion and immediate EPI both resulted in significantly enhanced uptake of nivolumab in all skin depths compared with intact skin (P < 0.05). With AFL, nivolumab concentrations reached 86.3 µg/cm³ (100 µm), 105.8 µg/cm³ (500 µm), and 19.3 µg/cm³ (1500 µm), corresponding to 2-10% of the applied concentration, with the highest deposition in the mid dermis. Immediate EPI delivered 429.4 µg/cm³ (100 µm), 584.9 µg/cm³ (500 µm), and 295.9 µg/cm³ (1500 µm) into the skin, corresponding to 29-58% of the applied nivolumab concentration. From qualitative visualization of the biodistribution, it appeared that nivolumab distributed in a horizontal and continuous homogenous band in the upper and mid dermis through AFL-exposed skin, whereas EPI-delivery showed a deep focal deposition extending into the deep dermis.

CONCLUSIONS

AFL-assisted passive diffusion and immediate EPI-assisted delivery show the potential to deliver therapeutic antibodies locally. Future in vivo and pharmacokinetic studies would reveal the full potential for topical antibody delivery by energy-based devices. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Treatment of alopecia areata with 2940-nm fractional erbium:yttrium-aluminum-garnet laser

Various laser therapies have been used for the treatment of alopecia areata (AA). Enhanced hair regrowth was reported with the use of ablative fractional 2940-nm erbium:yttrium-aluminum-garnet (Er:YAG) laser in a murine model. However, clinical effectiveness of fractional Er:YAG laser for hair disorders has not been investigated in human studies. The aim of our study was to assess the effectiveness of 2940-nm fractional Er:YAG laser in the treatment of chronic AA that is unresponsive to conventional therapies. Twenty-five AA patients underwent three sessions, each 4 to 6 weeks apart, of fractional Er:YAG laser. Clinical evaluation was done at baseline and 1 month post-treatment (follow-up) by photographic assessment. Subjective evaluation by patient satisfaction score was also performed. Photographic evaluation of the patients revealed a mean percent change in SALT score of 17.4 ± 3.5% at follow-up. A total of 16 patients who were treated for patchy AA of the scalp showed 27.8 ± 31.3% regrowth. Five patients who were treated for AA of the beard had 39 ± 34.2% regrowth. Fractional Er:YAG laser might be a therapeutic alternative for patients with patchy AA of the scalp and beard that is unresponsive to conventional therapies.

Management of recalcitrant vitiligo in Vogt-Koyanagi-Harada syndrome: Adjuvant ablative fractional laser

The course of dermatologic findings in Vogt-Koyanagi-Harada disease is variable. Herein, we report the remarkable repigmentation of widespread facial vitiligo lesions in an adolescent girl with Vogt-Koyanagi-Harada disease. The patient was treated with a combination of fractional erbium:YAG laser, topical tacrolimus, and phototherapy.

Fractional Ablative CO2 Laser Followed by Topical Application of Sodium Stibogluconate for Treatment of Active Cutaneous Leishmaniasis: A Randomized Controlled Trial

Conventional treatment of cutaneous leishmaniasis often leaves permanent scars with frequent psychosocial sequelae. The aim of this study was to compare the efficacy, safety, associated pain and final cosmetic outcome of fractional carbon dioxide (CO2) laser followed by topical application of sodium stibogluconate vs. sodium stibogluconate injections for the treatment of cutaneous leishmaniasis. A total of 181 lesions (20 patients) were randomly assigned to receive intralesional injections of sodium stibogluconate (control group) or fractional CO2 laser treatment followed by topical application of sodium stibogluconate (study group). The visual analogue scale (VAS) score of the control group was much higher than that of the study group (6.85 vs. 3.5, respectively, p<0.001). Both the patients and 2 blinded dermatologists found the final cosmetic outcome to be superior for laser-treated lesions (p = 0.001 vs. p =0.008 for controls). Fractional CO2 laser treatment followed by topical application of sodium stibogluconate is less painful and leads to a better final cosmetic outcome compared with intralesional injections of sodium stibogluconate.

Topical delivery of vismodegib using ablative fractional laser and micro-emulsion formulation in vitro

BACKGROUND AND OBJECTIVE

Hedgehog inhibitors such as vismodegib are targeted drugs widely used for the treatment of basal cell carcinomas; however, their use is significantly limited by frequent systemic side effects due to oral administration route. We aim to use ablative fractional laser (AFL) to enable the topical delivery of vismodegib to relevant dermal depths.

MATERIALS AND METHODS

Pig skin was treated in vitro with a fractional 10,600 nm CO₂ laser at 0 or 80 mJ/microbeam and exposed to vismodegib (6.4 mmol/L) in Franz-diffusion cells for 0.5, 4, and 24 hours (n = 54 samples), either formulated in a micro-emulsion composed of soybean oil and Tween 80 or dissolved in ethanol as vehicle control. Vismodegib biodistribution was studied at specific skin depths from 0 to 1,800 µm (incremental steps of 300 µm) by mass spectrometry.

RESULTS

Combination of AFL and vismodegib emulsion substantially enhanced the delivery of drug into the skin. Emulsion formulation alone yielded higher vismodegib skin concentrations compared to vehicle control in superficial and mid-dermis (0-900 µm, P = 0.002-0.015). The over-all highest concentration found (554.5 µmol/L) was reached at 24 hours in superficial (0-300 µm) AFL exposed skin, 7.6-fold higher than vehicle control (P = 0.002) and 9.7-101.6 fold higher than previously reported steady-state plasma concentrations in patients treated with oral vismodegib (5.5-56.9 µmol/L). Compared to intact skin, AFL exposure significantly increased skin concentrations of vismodegib even in deep skin layers (24 h, 900-1,800 µm, emulsion: 8.7-74.3 µmol/L vs. 0.0-0.0 µmol/L, P = 0.004-0.048; vehicle control: 23.7-50.6 µmol/L vs. 0.0-1.6 µmol/L, P = 0.002). The total delivery of vismodegib-emulsion into mid-deep dermal skin layers from 600 to 1,800 µm was for AFL exposed skin 8.2 fold higher than intact skin. Also, delivery of emulsion vismodegib by AFL was time-dependent as seen by the continuous increase in concentrations found over time, with highest uptake detected after 24 hours (4-24 hours, 0-900 µm, P = 0.002-0.004).

CONCLUSION

AFL enhances topical delivery of micro-emulsion formulated vismodegib, reaching concentrations similar to or above plasma concentrations previously reported in patients receiving oral vismodegib. Lasers Surg. Med. 51:79-87, 2019. © 2018 Wiley Periodicals, Inc.

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.

Treatment of ulcers with ablative fractional lasers

Chronic, nonhealing ulcers are a frustrating therapeutic challenge and investigation of innovative therapies continues to be an important research pursuit. One unique and newly applied intervention is the use of ablative fractional lasers. This technology has recently been employed for the treatment of hypertrophic, disfiguring and function-limiting scars, and was first shown to induce healing of chronic wounds in patients with persistent ulcers and erosions within traumatic scars. Recent reports suggest it may be applicable for other types of chronic wounds as well. The mechanism of action for this modality remains to be elucidated but possible factors include laser-induced collagen remodeling, photomicrodebridement and disruption of biofilms, and induction of a proper wound healing cascade.

Histologic comparison of microscopic treatment zones induced by fractional lasers and radiofrequency

INTRODUCTION

Fractional photothermolysis induces microscopic, localized thermal injury in the skin surrounded by undamaged viable tissue in order to promote wound healing.

OBJECTIVE

This study evaluated acute histologic changes following each single pass of various fractional lasers and radiofrequency (RF).

METHODS

Three male domestic swine were used. We used fractional Erbium:glass (Er:glass), Erbium:yttrium-aluminum-garnet (Er:YAG), CO2 lasers, and fractional ablative microplasma RF. We analyzed features and average values of the diameter, depth, and vertical sectional areas treated with each kind of laser and RF.

RESULTS

The microscopic treatment zone (MTZ) of fractional Er:glass resulted in separation of dermoepidermal junction with no ablative zone. Fractional Er:YAG provided the most superficial and broad MTZ with little thermal collateral damage. Fractional CO2 resulted in a narrow and deep "cone"-like MTZ. Fractional RF resulted in a superficial and broad "crater"-like MTZ.

CONCLUSIONS

This study provides the first comparison of MTZs induced by various fractional lasers and RF. These data provide basic information on proper laser and RF options. We think that these findings could be a good reference for information about fractional laser-assisted drug delivery.

Pretreatment with ablative fractional laser changes kinetics and biodistribution of topical 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL)

BACKGROUND AND OBJECTIVES

5-Aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) are porphyrin precursors used topically for photodynamic therapy (PDT). Previous studies have established that ablative fractional laser (AFXL) increases topical drug uptake. We evaluated kinetics and biodistribution of ALA- and MAL-induced porphyrins on intact and disrupted skin due to AFXL.

MATERIALS AND METHODS

Two Yorkshire swine were exposed to CO2 AFXL (10.6 µm, 1,850 µm ablation depth) and subsequent topical application of ALA and MAL cream formulations (20%, weight/weight). Porphyrin fluorescence was quantified by digital fluorescence photography (30, 90, and 180 minutes) and fluorescence microscopy at specific skin depths (180 minutes).

RESULTS

Porphyrins gradually formed over time, differently on intact and AFXL-disrupted skin. On intact skin (no AFXL), fluorescence photography showed that MAL initially induced higher fluorescence than ALA (t = 30 minutes MAL 21.1 vs. ALA 7.7 au, t = 90 minutes MAL 39.0 vs. ALA 26.6 (P < 0.009)) but reached similar intensities for long-term applications (t = 180 minutes MAL 56.6 vs. ALA 52 au, P = ns). AFXL considerably enhanced porphyrin fluorescence from both photosensitizers (P < 0.05). On AFXL-exposed skin, MAL expressed higher fluorescence than ALA for short-term application (t = 30 minutes, AFXL-MAL 26.4 vs. AFXL-ALA 14.1 au, P < 0.001), whereas ALA over time overcame MAL and induced the highest fluorescence intensities obtained (t = 180 minutes, AFXL-MAL 98.6 vs. AFXL-ALA 112.0 au, P < 0.001). In deep skin layers, fluorescence microscopy showed higher fluorescence in hair follicle epithelium for ALA than MAL (t = 180 minutes, 1.8 mm, AFXL-MAL 35.3 vs. AFXL-ALA 46.7 au, P < 0.05).

CONCLUSIONS

AFXL changes kinetics and biodistribution of ALA and MAL. It appears that AFXL-ALA favors targeting deep structures.

Combination ALA-PDT and ablative fractional Er:YAG laser (2,940 nm) on the treatment of severe acne

BACKGROUND

Scarring is a very common complication of severe acne and is difficult to treat by conventional methods. 5-Aminolevulinic acid (ALA) photodynamic therapy (PDT) is a novel treatment for improving acne lesions. Fractional laser resurfacing is a promising treatment for scar treatment because of its unique ability to stimulate the wound healing response and its depth of penetration.

OBJECTIVE

To evaluate the efficacy of combination therapies of ALA-PDT and ablative fractional Er:YAG laser (2,940 nm) for scarring lesions in severe acne patients.

METHODS

A prospective, single-arm, pilot study. Forty subjects with severe acne were treated with 15% ALA-PDT for four times at 10-day intervals. They then received ablative fractional Er:YAG laser treatment five times at 4-week intervals. Three independent investigators evaluated subject outcomes at 1, 3, 6, and 12 months post-treatment (primary outcome); patients also provided self-assessments of improvement (secondary outcome).

RESULTS

Significant reductions in acne score (P < 0.01) were obtained at follow-up visits after 1, 3, 6, and 12 months. After 6 month, the lesions showed overall improvement in all of subjects (good to excellent in acne inflammatory lesions), 80% overall improvement in acne scars. After 12 months, most of subjects had improved hypertrophic/atrophic scars (good to excellent in 85%) and no one had recurrent acne inflammatory lesions. Patient self-evaluation also revealed good to excellent improvements (on average) in acne lesions and scarring, with significant improvements in self-esteem after 6 months post-treatment.

CONCLUSIONS

PDT can control the inflammation and improve the severity of acne lesions. Fractional resurfacing is a promising new treatment modality for scars by stimulating wound healing and remodeling. The combination therapy is a promising option for severe acne to prevent and improve car formation.