Translational medicine in the field of ablative fractional laser (AFXL)-assisted drug delivery: A critical review from basics to current clinical status

Jet-injection assisted photodynamic therapy for superficial and nodular basal cell carcinoma: A pilot study

BACKGROUND

Photodynamic therapy (PDT) with topical δ-Aminolevulinic acid (ALA) has efficacy in treating basal cell carcinoma (BCC) but is limited by incomplete penetration of ALA into the deeper dermis. This prospective open-label pilot trial investigated the safety and efficacy of photosensitizer jet injection for PDT (JI-PDT) for BCC treatment. It was performed with 15 patients (n = 15) with histologically confirmed, untreated, low-risk nodular BCCs at a single institution.

METHODS

For the intervention, JI-PDT patients (n = 11) received two sessions of jet-injected ALA with PDT separated by four to 6 weeks. To further understand treatment technique, another group of patients (n = 4) received jet-injected ALA followed by tumor excision and fluorescence microscopy (JI-E). Treatment tolerability was assessed by local skin responses (LSR) score at five distinct time intervals. Fluorescence microscopy assessed protoporphyrin IX penetration depth and biodistribution within the tumor. At the primary endpoint, tumor clearance was evaluated via visual inspection, dermoscopy and reflectance confocal microscopy. Postinjection and postillumination pain levels, and patient satisfaction, were scored on a 0-10 scale.

RESULTS

Fifteen participants with mean age of 58.3, who were 15/15 White, non-Hispanic enrolled. The median composite LSR score immediately after JI-PDT was 5 (interquartile range [IQR] = 3) which decreased to 0.5 (IQR = 1) at primary endpoint (p < 0.01). Immunofluorescence of excised BCC tumors with jet-injected ALA showed photosensitizer penetration into papillary and reticular dermis. Of the 13 JI-PDT tumors, 11 had tumor clearance confirmed, 1 recurred, and 1 was lost to follow-up. 1/11 patients experienced a serious adverse event of cellulitis. 70% of patients had local scarring at 3 months. Patients reported an average pain level of 5.6 (standard deviation [SD] = 2.3) during jet injection and 3.7 (SD = 1.8) during light illumination.

CONCLUSIONS

Jet injection of ALA for PDT treatment of nodular low-risk BCC is tolerable and feasible and may represent a novel modality to improve PDT.

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

OBJECTIVES

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.

METHODOLOGY

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.

RESULTS

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.

CONCLUSION

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.

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

BACKGROUND AND OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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 therapy-resistant verruca plantaris with laser-assisted photodynamic therapy (PDT) with methyl aminolevulinate (MAL)]

Mosaic warts are a type of verruca vulgaris that occur almost exclusively on the soles of the feet. They are particularly known for their treatment resistance and high recurrence rate. Laser-assisted drug delivery (LADD) photodynamic therapy (PDT) with methyl aminolevulinate (MAL) offers a low pain treatment option with hardly any side effects in therapy-resistant cases of verruca plantaris. Pretreatment with an ablative fractional laser is especially important to obtain penetration of MAL through the human papillomavirus (HPV)-infected skin layer.

Fractional laser combined with 5-Aminolevulinic acid photodynamic therapy for the treatment of Cutaneous Rosai-Dorfman Disease: A case report

Rosai-Dorfman disease(RDD) is a rare benign histiocytic proliferative disorder. Cutaneous Rosai-Dorfman disease(CRDD)is a rare variant of RDD with lesions localized to the skin. We report a case of patients with CRDD who was refractory to methotrexate, thalidomide, cyclosporine, glucocorticoid for local injection and external use, but resolved with fractional laser combined with 5-aminolevulinic acid photodynamic therapy (ALA-PDT). We believe that fractional laser technology combined with ALA-PDT for CRDD is a minimally invasive, effective and satisfactory treatment.

The quantitative analysis of low-concentration (2%) ALA-PDT assisted with Q-switch 1064-nm Nd:YAG laser for acne vulgaris treatment

Conventional 5-aminolevulinic acid-photodynamic (ALA-PDT) therapy (10-20%) has been widely applied for moderate-to-severe acne. The aim of this study is to investigate the effects of non-ablative Q-switched 1064-nm Nd:YAG laser-assisted ALA-PDT with low concentration (2%) on the treatment of acne vulgaris. Enrolled patients were randomly assigned to 2 groups. One group received combined therapy of 2% ALA-PDT and non-ablative Q-switched 1064-nm Nd:YAG laser, and the other received only 2% ALA-PDT. Patients in each group had received 3-session treatments with 4-week intervals (week 0, 4, and 8). Sebum secretion, melanin index, erythema index, and transepidermal water loss (TEWL) were assessed at week 2, 8, 12, and 24. VISIA® skin image system score and global esthetic improvement scale (GAIS) were also evaluated. Twenty-four participants were enrolled and evenly randomized to two groups. Significant improvement in sebum secretion was noted in combined therapy group compared to the monotherapy group at week 12 (37.5% versus 16.3%), and the improvement would still be noted until week 24 (18.3% versus 17.4%). Combined group also showed more severe melanin index and erythema index after treatment. For VISIA® skin analysis, patients in combined group had better percentile ranking in porphyrins and red-light images. There were no significant differences in GAIS at the end of the follow-up between each group, whereas higher proportion of satisfaction was noted in combined group at week 2. With the assistance of laser, low concentrations (2%) of 5-ALA can provide effective phototoxic reactions in treating acne vulgaris. The satisfaction of patients is high with acceptable adverse effects.

Efficacy of fractional CO2 laser therapy combined with hyaluronic acid dressing for treating facial atrophic acne scars: a systematic review and meta-analysis of randomized controlled trials

The present work aimed to systematically identify the efficacy and safety of fractional carbon dioxide (CO2) laser plus hyaluronic acid (HA) dressing in dealing with facial atrophic acne scars. Randomized controlled trials (RCTs) concerning fractional CO2 laser in combination with HA dressing for treating atrophic acne scars were screened in 8 electronic databases (containing PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Internet, Wanfang, Sinomed as well as VIP). Besides, for the purpose of evaluating the risk of bias of the enrolled RCTs, the Cochrane Collaboration tool was adopted. Statistical analysis was completed using Revman5.3 software and Stata 14.0 software. Meanwhile, the quality of evidence was assessed by the GRADE system. Finally, 6 studies involving 623 patients were enrolled. According to the findings in this study, compared with fractional CO2 laser alone, fractional CO2 laser therapy combined with HA dressing reduced the scores of ECCA (échelle d'évaluation clinique des cicatrices d'acné) grading scale (MD=-3.37,95% CI [-5.03, -1.70], P<0.0001), shortened the time of crust formation (MD=-0.42,95% CI [-0.80, -0.04], P=0.03) and the time of crust removal(MD=-1.31,95% CI [-1.67, -0.95], P<0.00001), enhanced patient satisfaction (RR=1.85, 95% CI [1.44, 2.38], P<0.00001). All the reported adverse events including hyperpigmentation, erythema, edema, mild itching, and slight burning pain were controllable. In addition, fractional CO2 laser combined with HA dressing therapy had a lower incidence of hyperpigmentation than fractional CO2 laser alone (RR=0.37, 95% CI [0.23, 0.61], P<0.0001). The level of evidence for outcomes was classified to be low to moderate. According to our findings, fractional CO2 laser combined with HA dressing is efficacious and safe option for facial atrophic acne scars. Nevertheless, more high-quality trials are required for further verification in the future.

IGF1 synthesis after CO2 fractional laser resurfacing (FLR): New insights in the treatment of scalp actinic keratoses

OBJECTIVES

Actinic keratosis have a high risk of progression to a squamous cell carcinoma. Insulin-like growth factor 1 and its receptor play a relevant role in restoring repair of ultraviolet-induced cell damage. This pathway is reduced in patients older than 65 years. Ablative fractional laser resurfacing could normalize insulin-like growth factor 1 (IGF-1) secretion in elderly by recruiting new fibroblasts. The aim of the study is to evaluate restoration of IGF1 values by PCR in senescent fibroblasts after ablative fractional laser resurfacing.

METHODS

We enrolled 30 male patients with multiple actinic keratosis on the scalp, equally divided into two mirror areas of up to 50 cm2 , treating only the right one. We performed one skin biopsy for each area 30 days after treatment. Real-time PCR in fibroblasts was performed to assess the change in IGF1. At baseline and after 6 months, in vivo reflectance confocal microscopy examination was performed in all patients.

RESULTS

IGF1 values were increased in the treated side by about 60%. The right areas had fairly complete resolution of actinic keratosis at the last follow-up visit after 6 months with no appearance of new lesions. The mean number of actinic keratosis in the right area was reduced by more than 75% at four- and six-follow-up visits compared to the left area. The improvement in the right area was also evidenced by lower values of the mean AKASI (actinic keratosis area and severity index) score. Reflectance confocal microscopy showed a reduction of keratinocytic disarray and scales after treatment.

DISCUSSION

Taken together, all the clinical, laboratory, and in vivo results of our study allowed us to confirm that ablative fractional laser resurfacing is a valuable tool for the treatment of actinic keratosis and cancerization field, both for the management of clinically evident lesions and for preventing the occurrence of squamous cell carcinoma.

Optimistic and possible contribution of nanomaterial on biomedical applications: A review

Nanomaterials have many advantages over bulk materials, including enhanced surface-to-volume proportion as well as magnetic traits. It has been a steady rise in research with using nanomaterials in various biomedical fields in the past few decades. Constructing nanomaterials has emerged as a leading research primary concern in order to discover specialized biomedical applications. Since, their advantageous properties including chemical stability, non-toxicity, bio - compatibility, relatively high magnetization, and strong magnetic vulnerability, nanoparticles of iron oxide had already influenced implementations in different biomedical fields. Nanomaterials can be divided up into four nanomaterials such as metallic nanomaterials, bimetallic or alloy nanomaterials, metal oxide nanomaterials, as well as magnetic nanomaterials. Hence, the purpose of this review is to conduct such in discussion on emerging advancements in nanomaterials for biomedical, with such a special emphasis upon those options of nanomaterials including metallic nanomaterials: Au and Ag, bimetallic nanomaterials: Fe-Co and Fe-Pt, and metal oxides: TiO₂ and CeO₂. Securing this information gap will result in a better comprehension of the contribution of nanomaterial type and subsequent huge-scale applications in aspects of both their potential and challenges.

Targeted implementation strategies of precise photodynamic therapy based on clinical and technical demands

With the development of materials science, photodynamic-based treatments have gradually entered clinics. Photodynamic therapy is ideal for cancer treatment due to its non-invasive and spatiotemporal properties and is the first to be widely promoted in clinical practice. However, the shortcomings resulting from the gap between technical and clinical demands, such as phototoxicity, low tissue permeability, and tissue hypoxia, limit its wide applications. This article reviews the available data regarding the pharmacological and clinical factors affecting the efficacy of photodynamic therapy, such as photosensitizers and oxygen supply, disease diagnosis, and other aspects of photodynamic therapy. In addition, the synergistic treatment of photodynamic therapy with surgery and nanotechnology is also discussed, which is expected to provide inspiration for the design of photodynamic therapy strategies.

Local vasoregulative interventions impact drug concentrations in the skin after topical laser-assisted delivery

INTRODUCTION

The ability of ablative fractional lasers (AFL) to enhance topical drug uptake is well established. After AFL delivery, however, drug clearance by local vasculature is poorly understood. Modifications in vascular clearance may enhance AFL-assisted drug concentrations and prolong drug dwell time in the skin. Aiming to assess the role and modifiability of vascular clearance after AFL-assisted delivery, this study examined the impact of vasoregulative interventions on AFL-assisted 5-fluorouracil (5-FU) concentrations in in vivo skin.

METHODS

5-FU uptake was assessed in intact and AFL-exposed skin in a live pig model. After fractional CO₂ laser exposure (15 mJ/microbeam, 5% density), vasoregulative intervention using topical brimonidine cream, epinephrine solution, or pulsed dye laser (PDL) was performed in designated treatment areas, followed by a single 5% 5-FU cream application. At 0, 1, 4, 48, and 72 h, 5-FU concentrations were measured in 500 and 1500 μm skin layers by mass spectrometry (n = 6). A supplemental assessment of blood flow following AFL ± vasoregulation was performed using optical coherence tomography (OCT) in a human volunteer.

RESULTS

Compared to intact skin, AFL facilitated a prompt peak in 5-FU delivery that remained elevated up to 4 hours (1500 μm: 1.5 vs. 31.8 ng/ml [1 hour, p = 0.002]; 5.3 vs. 14.5 ng/ml [4 hours, p = 0.039]). However, AFL's impact was transient, with 5-FU concentrations comparable to intact skin at later time points. Overall, vasoregulative intervention with brimonidine or PDL led to significantly higher peak 5-FU concentrations, prolonging the drug's dwell time in the skin versus AFL delivery alone. As such, brimonidine and PDL led to twofold higher 5-FU concentrations than AFL alone in both skin layers by 1 hour (e.g., 500 μm: 107 ng/ml [brimonidine]; 96.9 ng/ml [PDL], 46.6 ng/ml [AFL alone], p ≤ 0.024), and remained significantly elevated at 4 hours (p ≤ 0.024). A similar pattern was observed for epinephrine, although trends remained nonsignificant (p ≥ 0.09). Prolonged 5-FU delivery was provided by PDL, resulting in sustained drug deposition compared to AFL alone at both 48 and 72 hours in the superficial skin layer (p ≤ 0.024). Supporting drug delivery findings, OCT revealed that increases in local blood flow after AFL were mitigated in test areas also exposed to PDL, brimonidine, or epinephrine, with PDL providing the greatest, sustained reduction in flow over 48 hours.

CONCLUSION

Vasoregulative intervention in conjunction with AFL-assisted delivery enhances and prolongs 5-FU deposition in in vivo skin.

Laser-assisted nanoparticle delivery to promote skin absorption and penetration depth of retinoic acid with the aim for treating photoaging

Retinoic acid (RA) is an approved treatment for skin photoaging induced by ultraviolet (UVA). Topically applied RA is mainly located in the stratum corneum (SC) with limited diffusion into the deeper strata. A delivery system capable of facilitating dermal delivery and cellular internalization for RA is critical for a successful photoaging therapy. Two delivery approaches, namely nanoparticles and laser ablation, were combined to improve RA's absorption efficacy and safety. The nanoparticle absorption enhancement by the lasers was compared between full-ablative (Er:YAG) and fractional (CO₂) modalities. We fabricated poly-L-lactic acid (PLA) and PLA/poly(lactic-co-glycolic acid) (PLGA) nanoparticles by an emulsion-solvent evaporation technique. The mean size of PLA and PLA/PLGA nanocarriers was 237 and 222 nm, respectively. The RA encapsulation percentage in both nanosystems was > 96 %. PLA and PLA/PLGA nanocarriers promoted RA skin deposition by 5- and 3-fold compared to free control. The ablative lasers further enhanced the skin deposition of RA-loaded nanoparticles, with the full-ablative laser showing greater permeation enhancement than the fractional mode. The skin biodistribution assay evaluated by confocal and fluorescence microscopies demonstrated that the laser-assisted nanoparticle delivery achieved a significant dermis and follicular accumulation. The cell-based study indicated a facile uptake of the nanoparticles into the human dermal fibroblasts. The nanoparticulate RA increased type I collagen and elastin production in the UVA-treated fibroblasts. A reduction of matrix metalloproteinase (MMP)-1 was also highlighted in the photoaging cells. The calculation of therapeutic index (TI) by multiplying collagen/elastin elevation percentage and skin deposition predicted better anti-photoaging performance in Er:YAG laser-assisted nanoparticle delivery than CO₂ laser. Nanoencapsulation of RA decreased the cytotoxicity against skin fibroblasts. In vivo skin tolerance test on a nude mouse showed less skin damage after topical application of the nanoparticles than free RA. Our results hypothesized that the laser-mediated nanoparticle delivery provided an efficient and safe use for treating photoaging.

Optical Imaging Visualizes a Homogeneous and Horizontal Band-Like Biodistribution of Large- and Small-Size Hydrophilic Compounds Delivered by Ablative Fractional Laser

The skin barrier generally limits the topical delivery of hydrophilic molecules. Ablative fractional laser (AFL) facilitates cutaneous drug uptake of smaller hydrophilic compounds in several studies. In this imaging-based study, we aim to investigate the cutaneous biodistribution of two different-sized hydrophilic compounds delivered by an ablative fractional CO₂ laser at minimally invasive settings. Intact or CO₂ AFL-pretreated (2.5 mJ/mb and 5% density) ex vivo porcine skin was topically applied with a large or small hydrophilic compound (fluorescence labeled antibody nivolumab (150,000 g/mol, n = 4) or ATTO 647N (746 g/mol, n = 3)). Samples were incubated for 20 h in a Franz cell setup, whereafter optical coherence tomography (OCT) was used to assess laser channel depth, and ex vivo confocal microscopy (EVCM) was used to assess epidermal thickness and cutaneous biodistribution of nivolumab and ATTO 647N. With an EVCM-assessed median epidermal thickness of 70.3 µm and OCT-assessed ablation depth of 31.9 µm, minimally invasive settings enabled shallow penetration into the mid-epidermis. The AFL-assisted uptake of the antibody nivolumab and the smaller compound ATTO 647N showed a similar homogenous and horizontal band-like biodistribution pattern that reached mid-dermis. No uptake of nivolumab or ATTO 647N was observed in intact skin. In conclusion, AFL-induced mid-epidermal laser channels facilitates the cutaneous delivery of two hydrophilic compounds that are distributed in a similar homogeneous and horizontal band-like pattern, irrespective of their molecular size.

Laser-assisted nanocarrier delivery to achieve cutaneous siRNA targeting for attenuating psoriasiform dermatitis

Psoriasis is an autoimmune skin disorder presenting the excessive expression of interleukin (IL)-6. The topical use of small interfering RNA (siRNA) has been increasingly discovered for treating skin diseases. A delivery system capable of protecting siRNA while facilitating both skin targeting and cellular entrance is critical for the successful medication of topically-applied siRNA. Herein, we developed a delivery system for siRNA based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles and combined this system with an ablative laser to promote skin absorption for topical psoriasis therapy. The siRNA absorption enhancement was compared by two laser modalities: a fractional CO₂ laser and a fully-ablative Er:YAG laser. We characterized the effect of the delivery system by the cellular uptake, IL-6 silencing, in vitro skin absorption, cutaneous biodistribution, and in vivo psoriasiform dermatitis in mice. The nanocarriers showed minimal cytotoxicity and facile cellular uptake to knock down the IL-6 expression. The nanoformulation containing a cationic surfactant (Forestall) for ion pairing with siRNA achieved a 66% and 77% IL-6 knockdown efficiency toward keratinocytes and macrophages, respectively. In the Franz cell absorption, the lasers increased the naked siRNA penetration to the receptor compartment by 3.7-5.0-fold but remarkably reduced skin deposition using imiquimod (IMQ)-treated psoriasiform skin as the barrier. The fractional laser facilitated nanoparticle-associated siRNA skin deposition up to 3.3-fold, whereas the transport of the nanocarriers to the receptor was negligible. Qualitatively, the lasers increased nanoparticle delivery in the epidermis with limited effect to elevate the penetration depth. The fractional-mediated nanocarrier delivery dramatically attenuated the erythema and scaly lesions of psoriasiform dermatitis. The histological examination displayed a reduction of epidermal hyperplasia and macrophage infiltration by the combination of laser and nanosystem. The passive and laser-assisted naked siRNA delivery was less effective in mitigating dermatitis. The topical delivery of fractional laser-assisted nanoparticles on mice resulted in a 56% IL-6 knockdown. Our results manifested the benefit of cutaneous siRNA targeting using ablative lasers to deliver nanocarriers for treating psoriatic inflammation.

Comparison of fractional erbium:YAG laser-assisted tranexamic acid delivery alone and in combination with oral tranexamic acid in melasma

Tranexamic acid (TA) emerged as a promising agent for melasma. However, due to its hydrophilic structure, topical TA should be combined with a penetration-enhancing strategy to augment efficacy. To evaluate the efficacy of fractional erbium:YAG laser-assisted delivery (LAD) of topical TA 5% either with or without oral TA treatment in recalcitrant melasma patients. The authors retrospectively assessed the treatment outcomes of melasma patients treated by fractional erbium:YAG LAD of topical TA 5%. Patients receiving a standard protocol including four biweekly laser sessions were eligible. The study included two groups: group 1 patients received oral TA and LAD of topical TA 5%, and group 2 patients received only LAD of topical TA 5%. Two blinded dermatologists reported pre-treatment and post-treatment modified MASI (mMASI) scores. Mean mMASI scores in both group 1 (n = 15) and group 2 (n = 19) were significantly lower at the end of the treatment than baseline values (p = 0.001; p = 0.022, respectively). The decrease of mMASI scores were higher in group 1 (median = 2.1) (64.7%) than in group 2 (median = 1.2) (41.8%) (p = 0.027). Fractional erbium:YAG LAD of topical TA 5% is an efficient treatment regimen for melasma patients recalcitrant to conventional treatment approaches. The implementation of oral TA to this regimen improves the therapeutic outcomes.

Antibiotic Combination Therapy: A Strategy to Overcome Bacterial Resistance to Aminoglycoside Antibiotics

After the first aminoglycoside antibiotic streptomycin being applied in clinical practice in the mid-1940s, aminoglycoside antibiotics (AGAs) are widely used to treat clinical bacterial infections and bacterial resistance to AGAs is increasing. The bacterial resistance to AGAs is owed to aminoglycoside modifying enzyme modification, active efflux pump gene overexpression and 16S rRNA ribosomal subunit methylation, leading to modification of AGAs' structures and decreased concentration of drugs within bacteria. As AGAs's side effects and bacterial resistance, the development of AGAs is time-consuming and difficult. Because bacterial resistance may occur in a short time after application in clinical practice, it was found that the antibacterial effect of the combination was not only better than that of AGAs alone but also reduce the dosage of antibiotics, thereby reducing the occurrence of side effects. This article reviews the clinical use of AGAs, the antibacterial mechanisms, the molecular mechanisms of bacterial resistance, and especially focuses a recent development of the combination of AGAs with other drugs to exert a synergistic antibacterial effect to provide a new strategy to overcome bacterial resistance to AGAs.

The Potential of CRISPR-Guided Therapies in the Dermatology Clinic

Over the past decade, CRISPR has rapidly made its way from the bench to the bedside, providing a newfound therapeutic avenue to not only treat genetic diseases but also permanently cure them. Although there are several clinical trials in early stages, there are so far no CRISPR-based clinical trials for cutaneous disease. In this review, we describe multiple cutaneous diseases that represent ideal targets for CRISPR-based therapeutics owing to known single gene‒causing mutations. We also explore the potential of CRISPR nucleases to treat inflammatory disorders such as eczema and psoriasis, which are not classically categorized as genodermatoses. We describe the therapeutic solutions for these diseases that are guided by various CRISPR-associated (Cas) effector proteins, for example, using Cas9 to permanently edit the DNA of somatic cells, Cas3 to target foreign DNA to combat viral/bacterial skin infections, and Cas13 to edit mutated RNA transcripts in diseases where permanent DNA editing is untenable. Furthermore, we discuss various drug delivery modalities for CRISPR therapeutics, including transdermal patches and microneedles, which are uniquely suited for dermatological diseases. In summary, we highlight the potential of CRISPR-based therapeutics to revolutionize the treatment of cutaneous disease with a goal of being accessible to the practicing dermatologist.

Cutaneous Delivery of Cosmeceutical Peptides Enhanced by Picosecond- and Nanosecond-Domain Nd:YAG Lasers with Quick Recovery of the Skin Barrier Function: Comparison with Microsecond-Domain Ablative Lasers

Picosecond or nanosecond-domain non-ablative lasers generate faster photothermal effects and cause less injury than microsecond lasers. In this study, we investigated the enhancing effect of 1064 nm picosecond- and nanosecond-domain neodymium (Nd):yttrium–aluminum–garnet (YAG) lasers on the cutaneous delivery of cosmeceutical peptides. Microsecond-domain fractional ablative CO2 and fully ablative erbium (Er):YAG lasers were also used for comparison. In the Franz diffusion cell study, pig or mouse skin was treated with a laser before exposure to palmitoyl tripeptide (PT)-1, PT-38, and copper tripeptide (CT)-1 at a concentration of 150 μM. Psoriasiform, atopic dermatitis (AD)-like, and photoaged skins were also developed as permeation barriers. The non-ablative laser elicited the ultrastructural disruption of the stratum corneum and epidermal vacuolation. All laser modalities significantly increased the skin permeation of peptides in vitro. The non-ablative laser chiefly enhanced peptide delivery to the receptor compartment, whereas the ablative laser mainly increased the intracutaneous peptide deposition. The picosecond- and nanosecond-domain Nd:YAG lasers elevated the amount of PT-1 in the receptor up to 40- and 22-fold compared with untreated skin, respectively. Laser treatment promoted peptide delivery in barrier-deficient and inflamed skins, although this enhancement effect was less than that observed in healthy skin. Fluorescence microscopy indicated the capability of the non-ablative laser to deliver peptides to deeper skin strata. The ablative laser confined the peptide distribution in the epidermis. Confocal microscopy showed that peptides penetrated the skin along the microdots created by the fractional Nd:YAG and CO2 lasers. The skin barrier function determined by transepidermal water loss suggested quick recovery when using a nanosecond-domain laser (within 4 h). A longer period was needed for the skin treated with the fully ablative Er:YAG laser (76–84 h). Nanosecond non-ablative laser-facilitated peptide delivery may become an efficient and safe approach for cosmeceutical applications.

Evaluation of Device-Based Cutaneous Channels Using Optical Coherence Tomography: Impact for Topical Drug Delivery

BACKGROUND

Topical medications play a large role in the management of cutaneous diseases, but penetration is limited. Device-assisted drug delivery using mechanical destruction, lasers, and other energy-based modalities can increase penetration and absorption through creation of transcutaneous channels.

OBJECTIVE

To examine real-time, in vivo cutaneous changes in response to various devices used to improve topical drug delivery through optical coherence tomography (OCT) imaging.

METHODS AND MATERIALS

Treatment was performed with 8 medical devices, including mechanical destruction, lasers, and other energy-based modalities. Optical coherence tomography was used for real-time, noninvasive, in vivo imaging.

RESULTS

Using OCT, microneedling and radiofrequency microneedling demonstrated no cutaneous channels. Both low-energy, low-density, fractional nonablative lasers produced transient channels, which closed within hours. The fractional nonablative 1,927-nm thulium fiber and 1,550-nm erbium fiber lasers created channels with epidermal debris within, which were still closing at 24 hours. The fractional thermomechanical ablative device and the fractional ablative CO2 laser produced channels that were still open at 24 hours. CO2 laser channels had thick rims of coagulated tissue and remained open for longer.

CONCLUSION

Demonstrable differences among the devices were seen, and only some can produce observable channels, the characteristics of which vary with each technology.

Fractional laser-assisted administration of human umbilical cord mesenchymal stem cells to reduce hypertrophic scars in rabbit ears

BACKGROUND

The formation of hypertrophic scar is due to the abnormal accumulation and remodeling of the extracellular matrix, especially collagen tissue. Our research was designed to investigate the treatment effect of different administrations of human umbilical cord-derived stem cells and to hypertrophic scars on rabbit ears.

METHODS

Thirty New Zealand female white rabbits were treated as hypertrophic scar models. PBS was injected into the scars on the right ear of each group as control, while human umbilical cord-derived stem cells or condition medium of human umbilical cord-derived stem cells were administrated into the left ear through subcutaneous injection or fractional laser-assisted administration. Gross examination, scar elevation index (SEI) calculation and sampling were executed 5 weeks after administration. Then H&E and Masson staining analysis and the expression levels detections of α-SMA, Collagen I, TGF-β1, IL-1β, and IL-6 were performed.

RESULTS

Our results demonstrated that the severity of hyperplasia was lower than the model group after stem cells and conditioned medium treatment. H&E and Masson staining results showed that the inflammation in scars was greatly alleviated and the degree of fibrosis was reduced after treatment. There was no significant difference in the therapeutic effect between subcutaneous injection or fractional laser-assisted administration. Both stem cells and conditioned medium can down-regulate SEI and factors expression levels in all groups. However, compared with the stem cells, the therapeutic effects of the conditioned medium were lower.

CONCLUSIONS

The results confirmed that stem cells had an available treatment effect on hypertrophic scars of rabbit ears. In addition to the paracrine pathway, stem cells may have other ways to treat hypertrophic scars. Fractional laser-assisted administration may become a potential administration of stem cell clinical application in the future.

Efficacy and safety of thermomechanical fractional injury-assisted corticosteroid delivery versus intralesional corticosteroid injection for the treatment of hypertrophic scars: A randomized split-scar trial

BACKGROUND

Disruption of the natural skin barrier in a controlled manner may be used to deliver drugs that enhance scar resolution.

OBJECTIVE

To compare the efficacy and safety of thermomechanical fractional injury (TMFI)-assisted topical corticosteroid delivery with corticosteroid injection in the treatment of hypertrophic scar (HTS).

MATERIALS AND METHODS

This was a randomized, split-scar, double-blinded study. Twenty-one subjects with HTS on the abdomen received five split-scar treatments of TMFI + Steroid and steroid injection alone. Changes in scar thickness, scar volume, and Vancouver Scar Scale (VSS) were analyzed. Patient self-assessment, VAS scores, and adverse effects were also evaluated.

RESULTS

Scar thickness, volume, and VSS scores of both segments improved significantly compared to baseline. On every follow-up visit, there were no significant differences in mean scar thickness reduction between the two treatment groups except at the 6-month follow-up where the mean scar thickness reduction of the steroid injection segment was significantly lower than that of the TMFI + Steroid segment (95% confidence interval [CI], 0.09-0.35; p = 0.002). Scar volume, VSS scores, and patient self-assessment also showed no significant differences between both segments on all visits. The steroid injection segment was significantly more painful than the TMFI + Steroid segment (95% CI, -2.16 to -1.29; p < 0.001). Adverse effects of skin atrophy, telangiectasia, and post-inflammatory hyperpigmentation were noted in the steroid injection segment, while no adverse effects were observed at the TMFI + Steroid segment.

CONCLUSIONS

TMFI-assisted topical corticosteroid delivery is an effective treatment for HTS with a lower risk of adverse effects compared with corticosteroid injection.

Efficacy and safety of laser-assisted combination chemotherapy: A follow-up study of treatment with 5-fluorouracil and cisplatin for basal cell carcinoma

BACKGROUND AND OBJECTIVES

There is a growing need for effective topical treatments for basal cell carcinoma (BCC). By altering the skin barrier, ablative fractional lasers (AFLs) enhance cutaneous uptake of the synergistic chemotherapeutic agents, cisplatin, and 5-fluorouracil (5-FU). In our recently reported clinical trial, AFL-assisted delivery of cisplatin and 5-FU showed favorable short-term clearance rates of 95% with good cosmetic results at 3 months. This follow-up study assessed sustained tumor clearance, safety, and cosmesis in the same patient cohort, observed 6- and 12-months posttreatment.

MATERIALS AND METHODS

This follow-up study assessed AFL-assisted cisplatin and 5-FU in low-risk BCC. Among the 18/19 patients who achieved clinical tumor clearance in our 3-months primary trial, all were included for a 6-months follow-up. At 12 months, 17/19 were included due to one 6-month residual. During follow-up visits, treated areas were evaluated for signs of recurrent tumour by clinical inspection and optical coherence tomography (OCT). Residual tumors were confirmed histologically. Cosmetic outcome was evaluated at both follow-up visits by patients and physicians.

RESULTS

Overall, complete tumor clearance was 89% (17/19) and 79% (15/19) at 6 and 12 months, respectively. Clearance rate for superficial BCCs (sBCCs) 1 year after treatment was 100% (6/6) and lower for nodular BCC (nBCC) at 69% (9/13). Among recurrent tumors, 67% (2/3) had received only a single treatment and all were of the nodular subtype, situated in the head and neck area. All histologically confirmed BCC recurrences were identified by OCT. Cosmetic outcomes were similarly rated "good" or "excellent" by patients and evaluators (p = 0.289 and p = 0.250). Treatment-related local skin reactions were mild and tolerable, consisting of persisting erythema in two patients at the end of the study. Dyspigmentation was commonly observed at both follow-up visits, while the appearance of scarring resolved in the majority of patients between 6 months (56%; 10/18) and 12 months (76%; 13/17).

CONCLUSION

AFL-assisted cisplatin + 5-FU in double sessions represents an acceptable and safe treatment strategy for low-risk sBCC, while clearance rates following single treatment or for nBCC seem inferior. This intensified topical strategy may be best suited to cases of multiple lesions or in instances where surgical excision or extended courses of at-home therapy is challenging.

Efficacy of the topical cyclosporine cream assisted by fractional carbon dioxide laser vs topical clobetasol cream for the treatment of plaque psoriasis: Randomized comparative study

BACKGROUND

In mild psoriasis, topical agents remain the mainstay of treatment. However, the available treatments are not satisfactory for a significant proportion of patients in many terms such as efficacy and safety. Because of these deficits, augmentation of therapeutic effect seems desirable.

THIS STUDY AIMS

To evaluate the efficacy of topical cyclosporine cream, delivered by fractional CO₂ laser vs the efficacy of topical clobetasol cream for the treatment of mild to moderate plaque psoriasis.

PATIENTS AND METHODS

Twenty-two patients with chronic plaque psoriasis involving <10% BSA were included in this study. They were randomly allocated into 2 groups. In Group A, patients were instructed to apply cyclosporine cream twice daily for 5 consecutive days per week immediately after fractional carbon dioxide laser session. While in Group B, clobetasol cream was applied twice daily for 5 consecutive days per week until complete clearance or for a maximum of 10 weeks. The efficacy was objectively assisted clinically and by histopathology by using the scores and skin biopsy.

RESULTS

There was a significant improvement of erythema, plaque elevation, and scaling (p < 0.001) with the use of topical cyclosporine cream delivered by the aid of fractional CO₂ laser, compared to base line. However, the improvement was more significant with topical clobetasol cream.

CONCLUSION

Laser-assisted delivery of topical cyclosporine can provide comparable clinical and pathological improvement to that of clobetasol in the psoriatic plaques. These findings were apparent in patients with less widespread disease. However, topical steroid showed more improvement.

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.

Treatment of Scars with Laser-Assisted Delivery of Growth Factors and Vitamin C: A Comparative, Randomised, Double-blind, Early Clinical Trial

BACKGROUND

Scarring can jeopardize the final result of plastic surgeries. Deep dermal injuries activate dermal fibroblasts that produce excessive amount of collagen and inflammatory cytokines and growth factors, which contributes to increased fibrous tissue and scarring tissue formation.

OBJECTIVES

The aim of this early study, double-blind, prospective, randomised clinical trial was to investigate the use of laser-assisted drug delivery (LADD) for scar improvement to support the establishment of LADD as standard therapy modality and to indicate suitable drugs for dermal administration.

MATERIAL AND METHODS

In total, 132 patients seeking scar treatment were consented and randomised. The control group (64 patients) received laser resurfacing immediately followed by skin surface application of Vitamin C and 68 patients received laser treatment followed by skin surface application of a cosmeceutical containing growth factors (GFs) and Vitamin C. Photographs were obtained before and three months after the procedure and submitted to three-dimensional reconstruction by the software Dermapix^®. Objective measurements provided by the software were statistically analysed and established the differences in the treatment result between the two groups.

RESULTS

There was a significant reduction in scar roughness and volume in both groups (p < 0.01). Mann-Whitney test confirmed that the group treated vitamin C and GFs presented significantly better results than the group treated with vitamin C alone (p < 0.01).

CONCLUSION

LADD has proven efficient as scars were reduced in both study groups. Furthermore, the addition of growth factors provided statistically significant better outcomes and resulted in more inconspicuous scars. No adverse reactions were observed.

CLINICAL TRIAL REGISTRATION

Plataforma Brasil under the number CAAE: 63710716.2.0000.5664.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Assessing the compliance of systematic review articles published in leading dermatology journals with the PRISMA statement guidelines: A systematic review

Background

Reporting quality of systematic reviews and meta-analyses is of critical importance in dermatology because of their key role in informing health care decisions.

Objective

To assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines.

Methods

This review was carried out in accordance with PRISMA guidelines. Included studies were reviews published across 6 years in the top 4 highest-impact-factor dermatology journals of 2017. Records and full texts were screened independently. Data analysis was conducted with univariate multivariable linear regression. The primary outcome was to assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the PRISMA statement.

Results

A total of 166 studies were included and mean PRISMA compliance across all articles was 73%. Compliance significantly improved over time (β = .016; P = <.001). The worst reported checklist item was item 5 (reporting on protocol existence), with a compliance of 15% of articles.

Conclusion

PRISMA compliance within leading dermatology journals could be improved; however, it is steadily improving.

Energy-based Devices for Hair Loss

Treatment options for hair loss have traditionally been limited to topical and systemic therapies. Systemic therapies for inflammatory hair disorders are often immunosuppressive, and systemic treatment of androgenetic hair loss can cause undesired effects on sexual and reproductive health. Topical agents have a favorable side effect profile compared with systemic therapies, but many topicals have poor transcutaneous absorption, limiting their concentration and action at follicular targets in the dermis.

Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial

Background

Despite promising results, laser-assisted drug delivery (LADD) is not yet considered as standard therapies and published data rely mainly on laboratory tests, animal experiments or cadaver skin.

Objectives

This double-blind, prospective, randomized clinical trial investigates the impact in topical application of vitamin C and a cosmeceutical containing growth factors (GFs) on periorbital wrinkles primarily treated with laser skin resurfacing.

Material and Methods

In total, 149 female patients with periorbital wrinkles were consented and randomized into two study groups, R-C (receiving vitamin C only) and R-CGF (receiving vitamin C and a cosmeceutical containing growth factors). The statistical analysis evaluated the efficacy of each treatment regimen using software readouts provided by a three-dimensional stereophotogrammetry system prior to treatment and three months after the procedure. Results were compared to confirm if there was a significant change in the skin roughness and the average depth of the wrinkles between the two groups after treatment.

Results

There was a significant reduction in both skin roughness and average depth of the wrinkles in the group treated with vitamin C and growth factors (p <0.01) than those treated with LADD followed by topical application of vitamin C alone. There were no cutaneous reactions or adverse systemic reactions observed in this study related to LADD with vitamin C and GFs.

Conclusion

Controlled laser application might have a great potential to facilitate the absorption of exogenous macromolecules by the skin. Periorbital wrinkles were reduced in both groups, but LADD using vitamin C and GFs provided significantly better results.

Level of Evidence II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Evaluation of the of the efficacy of Fractional Erbium-Doped Yttrium Aluminum Garnet Laser-Assisted Drug Delivery of Kojic Acid in the Treatment of Melasma; A split face, comparative clinical study

Melasma is a common, difficult to treat hyperpigmentary disorder. Recently, ablative fractional lasers were utilized to enhance topical agents delivery to treat different skin conditions. This work was designed to evaluate the efficacy of fractional Er:YAG laser in enhancing the effect of topical kojic acid in patients with facial melasma. The patients were randomly treated in a split-face mode, by simple randomization, either with kojic acid alone on one side or combined with fractional Er:YAG laser on the other side. Twenty five patients completed six laser sessions at 2 week interval. The severity of melasma was assessed before and after treatment in addition to 3 months follow up after the last treatment session. The response to the treatment was evaluated by Melasma Area and Severity Index Score, physician global assessment of photographs and patient satisfaction. The side treated with fractional Er:YAG laser and kojic acid cream was found to have a statistically significant better improvement than the side treated with kojic acid alone. The patients were reported mild tingling sensation and mild erythema on both sides. Using combination of fractional Er:YAG laser and topical kojic acid was effective in the treatment of melasma.

Developments and challenges in dermatology: an update from the Interactive Derma Academy (IDeA) 2019

The 2019 Interactive Derma Academy (IDeA) meeting was held in Lisbon, Portugal, 10-12 May, bringing together leading dermatology experts from across Europe, the Middle East and Asia. Over three days, the latest developments and challenges in relation to the pathophysiology, diagnosis, evaluation and management of dermatological conditions were presented, with a particular focus on acne, atopic dermatitis (AD) and actinic keratosis (AK). Interesting clinical case studies relating to these key topics were discussed with attendees to establish current evidence-based best practices. Presentations reviewed current treatments, potential therapeutic approaches and key considerations in the management of acne, AK and AD, and discussed the importance of the microbiome in these conditions, as well as the provision of patient education/support. It was highlighted that active treatment is not always required for AK, depending on patient preferences and clinical circumstances. In addition to presentations, two interactive workshops on the diagnosis and treatment of sexually transmitted infections/diseases (STIs/STDs) presenting to the dermatology clinic, and current and future dermocosmetics were conducted. The potential for misdiagnosis of STIs/STDs was discussed, with dermoscopy and/or reflectance confocal microscopy suggested as useful diagnostic techniques. In addition, botulinum toxin was introduced as a potential dermocosmetic, and the possibility of microbiome alteration in the treatment of dermatological conditions emphasized. Furthermore, several challenges in dermatology, including the use of lasers, the complexity of atopic dermatitis, wound care, use of biosimilars and application of non-invasive techniques in skin cancer diagnosis were reviewed. In this supplement, we provide an overview of the presentations and discussions from the fourth successful IDeA meeting, summarizing the key insights shared by dermatologists from across the globe.

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.

Laser-Assisted Hyaluronic Acid Delivery by Fractional Carbon Dioxide Laser in Facial Skin Remodeling: A Prospective Randomized Split-Face Study in France

BACKGROUND AND OBJECTIVES

Combining the efficacy of ablative fractional carbon dioxide lasers (AFXL) to laser-assisted hyaluronic acid delivery (LAHAD) has not yet been studied. The objective of our study was to evaluate the safety and the efficacy of laser-assisted hyaluronic acid (HA) delivery with AFXL in facial skin remodeling.

STUDY DESIGN/MATERIALS AND METHODS

We conducted a prospective, double-blinded, randomized split-face study on 20 patients from 30 to 70 years old, with a skin phototype from I to IV. Each patient received full-face treatment with AFXL, immediately followed by the application in droplets into the fractional ablative tunnels of 1 ml of HA gel on one hemiface and 1 ml of physiological saline on the other hemiface. To evaluate postlaser aftermath, the intensity of erythema, edema, and crusts was graded. To assess facial skin remodeling, we scored the improvement of skin texture, firmness, fine lines, and skin radiance from baseline. Patients were evaluated on the 3rd and 7th day, 1st and 3rd month using clinical evaluations, photographs, and patient questionnaires.

RESULTS

We showed equivalence in postlaser aftermath between HA-treated and nontreated hemiface. Trend data analyses at the 3rd month suggested that immediate application of HA after AFXL resulted in a greater improvement in facial skin remodeling, especially for skin texture (mean score of 2.60 vs. 2.45) and skin firmness (mean score of 2.55 vs. 2.40). Skin radiance showed the best improvement, reaching almost a score of 5/10.

CONCLUSIONS

LAHAD with AFXL is a safe treatment showing promising results in facial skin remodeling. These findings need to be confirmed by a larger study to evaluate the value of LAHAD in daily clinical practice. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Low-fluence laser-facilitated platelet-rich plasma permeation for treating MRSA-infected wound and photoaging of the skin

Platelet-rich plasma (PRP) is rich in cytokines and growth factors and is a novel approach for tissue regeneration. It can be used for skin rejuvenation but the large molecular size of the actives limits its topical application. In this study, low-fluence laser-facilitated PRP was delivered to evaluate its effect on absorption through the skin, infection-induced wound, and photoaging. The PRP permeation enhancement was compared for two ablative lasers: fractional (CO₂) laser and fully-ablative (Er:YAG) laser. In the Franz cell experiment, pig skin was treated with lasers with superficial ablation followed by the application of recombinant cytokines, growth factors, or PRP. The transport of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was negligible in intact skin and stratum corneum (SC)-stripped skin. Both lasers significantly elevated skin deposition of IFN-γ and TNF-α from PRP, and fully-ablative laser showed a higher penetration enhancement. A similar tendency was found for vascular endothelial growth factor and epidermal growth factor. Er:YAG laser-exposed skin displayed 1.8- and 3.9-fold higher skin deposition of platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-β1 from PRP, respectively. According to the confocal images, both laser interventions led to an extensive and deep distribution of IFN-γ and PDGF-BB in the skin. In the in vivo methicillin-resistant Staphylococcus aureus (MRSA) infection model, CO₂ laser- and Er:YAG laser-assisted PRP delivery reduced bacterial load from 1.8 × 10⁶ to 5.9 × 10⁵ and 1.4 × 10⁴ colony-forming units, respectively. The open wound induced by MRSA was closed by the laser-assisted PRP penetration. In the mouse photoaging model, elastin and collagen deposition were fully restored by combined PRP and full-ablative laser but not by PRP alone and PRP combined with fractional laser. Laser-facilitated PRP delivery even with a low fluence setting can be considered a promising strategy for treating some dermatological disorders.

Lessons Learned from the First Decade of Laser-Assisted Drug Delivery

Laser-assisted drug delivery augments the distribution and penetration of topically applied treatments, leading to enhanced delivery and bioavailability. We discuss the therapeutic application of laser-assisted drug delivery in clinical practice in cases of non-melanoma skin cancer, vitiligo, melasma, scarring, and alopecia (female pattern hair loss, male pattern hair loss, alopecia areata) as well as for vaccination, local anaesthesia, analgesia, viral warts, infantile haemangiomas and cosmetic uses, and we review clinical studies that have used this technique over the last decade. Our review shows that the application of laser-assisted drug delivery enhances topical agent efficacy, potentially reducing the agent concentration and duration of topical treatment required. Future research into the use of laser-assisted drug delivery before topical therapies is needed to establish the optimal techniques to enhance drug delivery and thus improve patient outcomes.

Fractionated carbon dioxide (CO2) laser treatment contributes to trans-nail penetration of rhodamine B and changes of cytokine microenvironment

This study is to determine the role of the fractional CO2 laser in topical drug delivery and the impact of local immune responses. Experimental rabbit nails were treated with fractionated CO2 laser at varied fluencies of 20 mJ, 25 mJ, and 30 mJ and half of which were coated with rhodamine B (RhB). Histological examination was performed by hematoxylin and eosin staining; the penetration of RhB was assessed by the use of confocal laser scanning microscopy; and the expressions of IFN-γ and IL-4 mRNA in situ were detected by means of qPCR at 12 h, 24 h, 3 days, and 7 days post-laser irritation. The fractional CO2 laser could generate microscopic treatment zones in nail plates, and the depths of these micropores as well as the permeation of RhB in nails increased significantly in an energy-dependent manner. Importantly, the laser irritation led an upregulation of local IFN-γ mRNA expression accompanied by a downregulation of IL-4 mRNA expression. The ultrapulsed ablative fractionated CO2 laser may assist topical drug delivery, and may drive stronger local Th1 responses due to an imbalance of IFN-γ/IL-4 expressions, suggesting that the combination of ablative fractionated CO2 laser with topical agents would be an effective option for the treatment of onychomycosis.

Update Dermatologische Lasertherapie II – Weiterentwicklung der photodynamischen Therapie durch Laser‐assistierte transkutane Applikation von Topika

Die technische Fortentwicklung der jüngeren Vergangenheit bietet dem Dermatologen Zugriff auf neue Laser, Strahlquellen und Behandlungskonzepte. Seit langem eingeführte Wellenlängen zur Ablation sind nunmehr fraktioniert applizierend verfügbar und stehen nunmehr für eine wirksamere und effizientere Behandlung von zahlreichen Hautveränderungen zur Verfügung. Das gezielte Einbringung von Topika (laser assisted drug delivery; LADD) ist das wichtigste Beispiel. Die LADD erfordert eine spezifische Weiterbildung, um sicher und wirksam zur Therapie (prä-)maligner nichtmelanozytärer Neoplasien der Haut wie der Feldkanzerisierung in Form der Laser-assistierten photodynamischen Therapie angewandt werden zu können. Bisher verfügbare Daten weisen auf eine höhere Effektivität im Vergleich zu konventionell verwendeten Topika hin, wobei anhaltend über Weiterentwicklungen berichtet wird. Unter anderem wurde die Kombination mit Tageslicht oder alternativen tageslichtähnlichen Strahlquellen bekannt. Dieses Update basiert wie zitiert gekürzt und aktualisiert auf "Paasch, U. 2019. Laser-assistierte photodynamische Therapie. p. 226-239. In G. Kautz (ed.) Energie für die Haut. Springer Nature, Springer Nature.".

Update on dermatologic laser therapy II - advances in photodynamic therapy using laser-assisted drug delivery

Technical advances in recent years have led to the development of new dermatologic laser systems, light sources, and treatment concepts. With the introduction of ablative fractional lasers (using common wavelengths) in the field of dermatology, it is now possible to more effectively and efficiently treat a variety of skin disorders. One important example of these advances is laser-assisted drug delivery (LADD). A type of LADD, laser-assisted photodynamic therapy has been successfully employed in the treatment of non-melanoma skin cancer including field cancerization. This treatment concept has been continually modified and today includes the use of daylight as well as artificial daylight systems. This update is based as cited, shortened and updated according to "Paasch,U. 2019. Laser-assistierte photodynamische Therapie. p. 226-239. In G.Kautz (ed.) Energie für die Haut. Springer Nature, Springer Nature".

[Photodynamic therapy-trends and new developments]

Photodynamic therapy (PDT) is a licensed and established procedure for the treatment of actinic keratosis, basal cell carcinoma, and Bowen's disease, but there are several new and clinically relevant developments and trends. These concern on the one hand the main components of PDT, which are the photosensitizer and the light source. Furthermore, modifications and therapy combinations have been developed that lead to an improved therapeutic efficacy. An important aspect of field-directed PDT is also skin cancer prevention. Finally, PDT has been used successfully for nonlicensed indications including inflammatory diseases and skin rejuvenation. This article focuses on these new developments and on recent guideline recommendations.

Beyond Mohs surgery and excisions: A focused review of treatment options for subtypes of basal cell carcinoma

Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer. It originates from undifferentiated cells in the basal cell layer of the epidermis or from the outer root sheath of the hair follicle. The most important factor in development of BCC is ultraviolet radiation. Surgery is considered the gold standard of treatment for BCC. However, nonsurgical options are available for individuals who are unsuitable for surgery. The purpose of this review is to summarize the efficacy and indications of alternative, nonsurgical treatments that can be used in the management of BCC. An extensive literature review was performed for the nonsurgical options for the treatment of BCC. Resources searched included PubMed and Google Scholars, limited to the years 1995 to 2020. Key words searched included BCC, destructive methods, photodynamic therapy (PDT), radiotherapy, topical medication, laser, hedgehog pathway inhibitors (HPIs). The most relevant results such as systematic reviews, randomized controlled trials, or comparative studies were selected to provide a summary for the most common nonsurgical methods used for treating BCC. Effective nonsurgical treatments for BCC include destructive methods (eg, curettage alone, cryosurgery, or electrodessication), PDT, topical medications, radiotherapy, laser, and HPIs. Nonsurgical therapeutic alternatives are safe and effective for the treatment of BCC. Factors such as tumor location, size, and histopathological subtype should be taken into consideration when selecting optimal treatment. In addition to clinical factors, cosmetic results and patient preference should be considered.

Development of a Predictive Monte Carlo Radiative Transfer Model for Ablative Fractional Skin Lasers

It is possible to enhance topical drug delivery by pretreatment of the skin with ablative fractional lasers (AFLs). However, the parameters to use for a given AFL to achieve the desired depth of ablation or the desired therapeutic or cosmetic outcome are hard to predict. This leaves open the real possibility of overapplication or underapplication of laser energy to the skin. In this study, we developed a numerical model consisting of a Monte Carlo radiative transfer (MCRT) code coupled to a heat transfer and tissue damage algorithm. The simulation is designed to predict the depth effects of AFL on the skin, verified with in vitro experiments in porcine skin via optical coherence tomography (OCT) imaging. Ex vivo porcine skin is irradiated with increasing energies (50-400 mJ/pixel) from a CO₂ AFL. The depth of microscopic treatment zones is measured and compared with our numerical model. The data from the OCT images and MCRT model complement each other well. Nonablative thermal effects on surrounding tissue are also discussed. This model, therefore, provides an initial step toward a predictive determination of the effects of AFL on the skin. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

A Comparison of Human and Porcine Skin in Laser-Assisted Drug Delivery of Chemotherapeutics

BACKGROUND AND OBJECTIVES

Porcine skin is a widely used model in diffusion studies, but its usefulness for laser-assisted drug delivery (LADD) has not been evaluated in comparison with human skin. This study compared porcine and human skin in ex vivo LADD diffusion studies.

STUDY DESIGN/MATERIALS AND METHODS

Ex vivo ablative fractional laser (AFL) treatments (5, 20, and 80 mJ/mb) were applied to skin samples from three sources: human, normal pig (Duroc × Landrace × Yorkshire breed), and a hyperkeratotic pig phenotype. Samples were stained using hematoxylin and eosin, photo-documented, and measured digitally. Samples (20 mJ/mb) were exposed to bleomycin or 5-fluorouracil (5-FU) for 19 hours in Franz diffusion cells. Drug uptake was quantified at three skin depths (100, 500, and 1,500 µm) by high-performance liquid chromatography-mass spectrometry. Drug biodistribution and endogenous lipids were visualized by matrix-assisted laser desorption/ionization-mass spectrometry imaging.

RESULTS

Epidermal and dermal thicknesses of human and normal pig skin were similar (76-87 µm and 1,668-1,886 µm, respectively; P = 0.082-0.494). Endogenous lipids were investigated, and 116 compounds were identified. Of these compounds, 100 were found in all three skin types, while six were present exclusively in human skin. Laser channel depths (20 mJ/mb) in human and normal pig skin were similar (1,081 vs. 1,126 µm; P = 0.588). Bleomycin uptake was similar in all skin types at all depths (101.4-175.6 µg/cm³ ; P = 0.132-0.699). 5-FU uptake in human and normal pig skin was similar at 100 and 500 µm (80.5 vs. 140.3 µg/cm³ and 131.2 vs. 208.1 µg/cm³ , respectively; P = 0.065-0.093). At 1500 µm, 5-FU concentrations in the porcine skin types differed from those in human skin (104.7 vs. 196.7-344.8 µg/cm³ ; P = 0.002-0.026). Drug biodistribution was similar among skin types, but differences between bleomycin and 5-FU biodistribution were observed.

CONCLUSIONS

Normal porcine and human skin showed similar morphology, the composition of endogenous lipids, and AFL-assisted cutaneous uptake, and biodistribution of chemotherapeutics. Therefore, normal porcine skin, but not hyperkeratotic pig phenotype skin, is a practical and reliable model for healthy human skin in ex vivo LADD diffusion studies. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

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.

Enhancement of skin permeability with thermal ablation techniques: concept to commercial products

Traditionally, the skin is considered as a protective barrier which acts as a highly impermeable region of the human body. But in recent times, it is recognized as a specialized organ that aids in the delivery of a wide range of drug molecules into the skin (intradermal drug delivery) and across the skin into systemic circulation (transdermal drug delivery, TDD). The bioavailability of a drug administered transdermally can be improved by several penetration enhancement techniques, which are broadly classified into chemical and physical techniques. Application of mentioned techniques together with efforts of various scientific and innovative companies had made TDD a multibillion dollar market and an average of 2.6 new transdermal drugs are being approved each year. Out of various techniques, the thermal ablation techniques involving chemicals, heating elements, lasers, and radiofrequency (RF) are proved to be more effective in terms of delivering the drug across the skin by disrupting the stratum corneum (SC). The reason behind it is that the thermal ablation technique resulted in improved bioavailability, quick treatment and fast recovery of the SC, and more importantly it does not cause any damage to underlying dermis layer. This review article mainly discussed about various thermal ablation techniques with commercial products and patents in each classes, and their safety aspects. This review also briefly presented anatomy of the skin, penetration pathways across the skin, and different generations of TDD.

Efficacy of Er,Cr:YSGG laser-assisted delivery of topical anesthesia in the oral mucosa

OBJECTIVE

Lasers which can reduce epithelium thickness will enhance the penetration of topical drugs. To date, no study has assessed the efficacy of this technique in the oral mucosa. The aim of this study was the evaluation of efficacy of this technique in increasing the effect of topical anesthesia in the oral mucosa.

MATERIALS AND METHODS

On 20 volunteers, half of the lower lip mucosa was irradiated with Er,Cr:YSGG laser with 2780 nm wavelength and 1.3 J/cm² energy for 1 min; then, topical lidocaine was applied on the entire lower lip mucosa. After 5 min, a 27-gauge needle was inserted to each half of the lip mucosa, and the length of the needle inserted into the mucosa without feeling pain was considered the depth of insertion. This measurement was repeated every 15 min for 1 h.

RESULTS

The mean depth of anesthesia at the control side was 6.95 ± 2.43, 8.45 ± 4.05, 6.5 ± 3.00, and 3.85 ± 2.08 mm at 5, 20, 35, and 60 min, respectively. These values at the test side were 12.25 ± 5.42, 13.25 ± 5.02, 11.4 ± 5.03, and 9.10 ± 5.84 mm, respectively. According to repeated-measures ANOVA, the effect of the type of the treatment on the depth of insertion was significant (P < 0.001).

CONCLUSIONS

The results showed that irradiation of Er,Cr:YSGG laser before the topical application of the anesthetic agents on the oral mucosa increases their efficacy.

CLINICAL RELEVANCE

Topical anesthesia is used to enhance dental procedures painlessly, but there is controversy in their efficacy. Laser-assisted drug delivery to the oral mucosa can enhance their efficacy.

Fractional CO2 laser-assisted Botulinum toxin type A delivery for the treatment of primary palmar hyperhidrosis

Intradermal injections of botulinum toxin type A (BTX-A) have been used successfully to treat patients with primary palmoplantar hyperhidrosis (PPH). However, problems with local injections of BTX-A for palmar hyperhidrosis include injection pain and reduced palmar muscle strength. This case series describes three patients with PPH. Patients were followed up for 3 months and assessed using the minor iodine starch test and the visual analog scale (VAS). Over two sessions within a 2-week interval, all patients received treatment on one palm, while the other palm served as the untreated control. Treated palms received fractional CO₂ laser therapy and immediate post-operative topical application of BTX-A solution for a total of 50 units. Sweat production was assessed based on the size of the sweat-producing area (measured by the minor iodine starch test) and subjective assessment of sweat production using the visual analog scale (VAS) at baseline, 2 weeks after the first treatment, and 1, 2, and 3 months after the second treatment. In the BTX-A-treated palm, the decrease in the mean sweat production was 51.6% at 2 weeks after the first treatment, and 88.5%, 67.8%, and 52.9%, at 1, 2, and 3 months after the final treatment when compared to the baseline. In the untreated palms, the decrease in the mean sweat production was 2% on all follow-ups when compared to the baseline. No adverse effect was observed in any patient. Fractional CO₂ laser is a safe technique for BTX-A delivery on the palm area and is demonstrated to be safe and effective in decreasing sweat secretion of hyperhidrosis palm.