Photodynamic therapy for skin rejuvenation: treatment options - results of a consensus conference of an expert group for aesthetic photodynamic therapy

[Oxidation-reduction potential of tissues of the oral mucosal wound surface under the photodynamic action]

The purpose of the study was to examine the condition of the pro-antioxidant balance of the homogenates of tissues of the oral mucosal wound surface in vivo experiment under the photodynamic action of combined two-wave radiation to eliminate its damaging effect on the structures of cell membranes.

MATERIALS AND METHODS

On the mucous membrane of the cheeks of sexually mature female autocrats of Wistar rats (n=72) experimental models of wound surfaces with a diameter of 3 mm were formed. The animals were divided into groups: control (n=36) and experimental (n=36). In the experimental group, a single photodynamic exposure was carried out for the 1st postoperative day with a sequential combined light radiation at two wavelengths (660 nm and 405 nm) with a total dose of 15 J/cm². Wound management was carried out traditionally in the control group of animals. The observation periods were 3, 7 and 14 days.

RESULTS

Macroscopic examination of the wound surface indicated complete epithelialization of the wound on the 7th day in the experimental group of animals and on the 14th day in the control group. Significant and sharp decline in free-radical oxidation processes (Imax, S, Z index) intensity was recorded in the experimental animals at earlier periods in comparison with the initial data and control results, when analyzing the results of studies of homogenates of animal tissues. A similar pattern was observed in the evaluation of lipid peroxidation products, especially in the early days of observations. The reported results were supported by the activation of antioxidant enzymes in the experimental group compared to control data and baseline data.

CONCLUSION

Thus, a combined photodynamic action using two wavelengths with a combined dose of 15 J/cm² provides safety and low invasiveness for use on the oral mucous membrane and, may be used to stimulate regeneration of the wound surface, which requires further experimental testing.

[Decision criteria and patient characteristics for patient-oriented treatment of field cancerization : Standardized algorithm for personalized treatment concepts]

Hintergrund

Aktinische Keratosen (AK) zeichnen sich durch einen chronischen Verlauf aus, und häufig ist ein ganzes Hautareal betroffen (Feldkanzerisierung). Die patientenindividuelle Abwägung therapiespezifischer Vor- und Nachteile einer feldgerichteten Therapie ist herausfordernd.

Fragestellung

Ziel der vorliegenden Arbeit war die Entwicklung und Evaluierung patientenorientierter Entscheidungskriterien, die sich für die pragmatische Einordnung einer AK-Feldtherapie im Behandlungsalltag bei Patienten mit besonderer Prädisposition zur Feldkanzerisierung eignen (Patiententyp 1 bis 3).

Material und Methoden

Die Entwicklung der Entscheidungskriterien und der Patiententypologie erfolgte im Rahmen eines nominalen bzw. strukturierten Multi-level-Gruppenprozesses. Anhand der patientenrelevanten Entscheidungskriterien, der verfügbaren Evidenz aus klinischen Studien und entlang der Patiententypologie wurde ein Bewertungsalgorithmus etabliert, und feldgerichtete AK-Therapieoptionen wurden systematisch evaluiert.

Ergebnisse

Als patientenrelevante Kriterien für die Therapieentscheidung wurden u. a. Effektivität, Sicherheit, Praktikabilität der Therapie, Adhärenz, Kosmetik, Patientenpräferenz und Komorbiditäten identifiziert und näher spezifiziert. In Bezug auf diese Entscheidungskriterien und Patiententypen, bei denen eine Feldtherapie vorrangig indiziert ist, erfüllte die photodynamische Therapie mit Tageslicht das therapiebezogene Anforderungsprofil in besonderem Maße.

Schlussfolgerung

Die Definition von patientenrelevanten und therapiebezogenen Entscheidungskriterien in der AK-Feldtherapie erlaubt eine strukturierte und gleichzeitig praxisorientierte Herangehensweise, um spezifische Therapieoptionen einzuordnen und individuelle Therapieentscheidungen herzuleiten.

An update in clinical utilization of photodynamic therapy for lung cancer

Lung cancer is one of the leading causes of cancer-related death worldwide, with nearly 1.8 million-diagnosis and 1.59 million deaths. Surgery, radiotherapy, and chemotherapy in individual or combination are commonly used to treat lung cancers. Photodynamic therapy (PDT) is a highly selective method for the destruction of cancer cells by exerting cytotoxic activity on malignant cells. PDT has been the subject of numerous clinical studies and has proven to be an effective strategy for cancer therapy. Clinical studies revealed that PDT could prolong survival in patients with inoperable cancers and significantly improve quality of life. For inoperable lung cancer cases, PDT could be an effective therapy. Despite the clinical success reported, PDT is still currently underutilized to treat lung cancer and other tumors. PTD is still a new treatment approach for lung cancer mainly due to the lack of enough clinical research evaluating its' effectiveness and side effects. In this review, we discuss the current prospects and future potentials of PDT in lung cancer treatment.

[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.

Split-Sided Chest Study of Skin Rejuvenation Comparing Low-Energy, 1,927-nm Thulium Fractional Laser Treatment Prior to Photodynamic Therapy Versus Photodynamic Therapy Alone

Background and Objectives

Treatment of photoaging and intrinsic aging of the chest, with the associated concerns of skin roughness, uneven pigmentation, laxity, atrophy, and telangiectasias, can be problematic because of the potential for worsened esthetic outcomes with existing treatments. This study assessed the efficacy and safety of using nonablative fractional laser therapy (FLT) pretreatment with photodynamic therapy (PDT) versus PDT alone for chest rejuvenation.

Study Design/Materials and Methods

In a randomized, evaluator‐blinded, split‐sided study, adult female patients with photodamage to the chest received three treatment courses over an 8‐week period with follow‐up visits at Weeks 12 and 20. FLT was applied to one side of the chest, randomly assigned at baseline, followed by aminolevulinic acid‐based PDT, delivered using a thermal, short incubation, broad area technique, to both sides of the chest. In‐person and photographic assessments were conducted using five‐point scales to evaluate outcomes including rhytides, pigmentation, skin texture, and telangiectasias.

Results

Eleven adults completed the study, of whom 11 had improved scores for rhytides and 10 had improved scores for skin texture at Week 20. There was no significant difference in any efficacy outcome between FLT and PDT and standard PDT alone. The severity of adverse events was rated significantly greater with the combined FLT–PDT treatment vs PDT alone.

Conclusions

Significant improvements were observed vs baseline for both sides of the chest treated with FLT–PDT or standard PDT following three treatment sessions. No significant difference in efficacy was observed between treatment approaches, although adverse events were more severe on the FLT‐pretreated side. This study was not registered as it qualified as a nonsignificant risk study. Lasers Surg. Med. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Photodynamic therapy for aesthetic-cosmetic indications

Photodynamic therapy (PDT) is a well-established, non-invasive treatment for a variety of dermatologic disorders, including actinic keratosis. Furthermore, PDT results in marked improvements in the signs of skin aging, although currently there are no standardized guidelines for PDT in skin rejuvenation. Two types of PDT are available: conventional-PDT (c-PDT) and the newly introduced daylight-PDT (DL-PDT). Both require a topical photosensitizer, a light source and oxygen, and both are comparable regarding safety and efficacy for treatment of photo-induced skin aging. Treatment is particularly effective for improvement of fine wrinkles, skin roughness, actinic elastosis and mottled hyperpigmentation. The most widely studied topical sensitizers used in PDT are 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL). A range of pre-treatment procedures help improve skin absorption of the photosensitizer and lead to significantly improved efficacy. A variety of activating light sources can be used for c-PDT, while DL-PDT uses natural daylight, making it easier to treat larger areas of photodamaged skin. A major limitation of c-PDT is significant treatment-related pain, but DL-PDT has proved to be an almost pain-free procedure. Treatment duration is based on individual patient need but most patients receive 2 to 3 treatment cycles, with results fully evident 3-6 months post-treatment. PDT for aesthetic-cosmetic treatments has established its value in modern procedural dermatology as mono- or combination therapy. A major, unique advantage of PDT is that it is a non-invasive treatment that effectively rejuvenates photodamaged skin, while successfully treating a range of dermatologic conditions, including prevention and therapy of pre-cancerous actinic keratosis.

Comparison of the Effect of Skin Preparation Pads on Transepidermal Water Loss in Ex Vivo Human Skin

Introduction

Pre-treatment of the skin to remove scales and crusts prior to photodynamic therapy (PDT) is essential to enhance the uptake of topically applied methyl aminolevulinate (MAL) and to improve treatment efficacy. This study compared the effect of two different skin preparation pads on skin integrity in ex vivo human skin.

Methods

Ex vivo human skin samples from three donors were pre-treated in triplicates with PREPSTER™ (PR) skin preparation pad (6, 8, and 10 passages) or Ambu Unilect™ (A-UN) skin preparation pad (6, 8, and 10 passages). In addition, skin samples were pre-treated with tape strippings (10 adhesive tape strips) as a reference method for comparison. Transepidermal water loss (TEWL) was measured on intact skin and following skin barrier impairment using skin preparation pads and tape stripping. Histological analysis was performed to verify the impairment of the stratum corneum (SC) barrier function in samples from intact skin (control), 10 tape strippings (reference method), 10 passages of PR, and 10 passages of A-UN.

Results

TEWL increased with the increasing number of passages of skin preparation pads, with 2.4- and 3.3-fold increases following 10 passages of A-UN and PR, respectively, versus a 2.2-fold increase with 10 tape strippings (reference). Histological analysis showed only partial removal of the SC, with no damage observed on the epidermis, regardless of the procedure used.

Conclusion

Pre-treatment of skin using PR and A-UN skin preparation pads markedly increases TEWL, indicating slight impairment of the SC barrier function. Comparison of both skin preparation pads showed that PR pad consistently induced significantly higher TEWL than A-UN pad (p < 0.05), regardless of the number of passages. Both skin preparation pads are thought to increase the uptake of MAL and can therefore be used for the preparation of skin prior to PDT.

Funding

Nestlé Skin Health – Galderma R&D.

Consensus recommendations on the use of daylight photodynamic therapy with methyl aminolevulinate cream for actinic keratoses in Australia

Australia has the highest prevalence of actinic keratoses (AK) worldwide. Because of the risk of transformation of AK to invasive squamous cell carcinomas, consensus guidelines recommend that AK are removed using appropriate therapies to prevent progression to invasive disease. Daylight photodynamic therapy (PDT) is emerging as an efficacious treatment for AK, particularly for patients who require treatment of large areas of chronic actinic damage that can be exposed easily to daylight. Daylight PDT with methyl aminolevulinate (MAL) cream is a simple treatment for AK, almost painless, well tolerated and convenient, requiring minimal time in the clinic. Randomised controlled studies from northern Europe and Australia support the use of daylight PDT as an effective therapy for grade I and II AK on the face and scalp. There is sufficient daylight to conduct daylight PDT in Australia at any time of the year and during most weather conditions. Hence, daylight PDT with MAL can be included as an effective and well-tolerated new treatment option for the treatment of AK in Australia. These consensus recommendations provide guidelines for Australian clinicians on the use of daylight PDT in the treatment of diagnosed AK.

Photodynamic therapy: current status and future directions

Photodynamic therapy (PDT) is a minimally invasive therapeutic modality used for the management of a variety of cancers and benign diseases. The destruction of unwanted cells and tissues in PDT is achieved by the use of visible or near-infrared radiation to activate a light-absorbing compound (a photosensitizer, PS), which, in the presence of molecular oxygen, leads to the production of singlet oxygen and other reactive oxygen species. These cytotoxic species damage and kill target cells. The development of new PSs with properties optimized for PDT applications is crucial for the improvement of the therapeutic outcome. This review outlines the principles of PDT and discusses the relationship between the structure and physicochemical properties of a PS, its cellular uptake and subcellular localization, and its effect on PDT outcome and efficacy.

Photodynamic therapy with topical aminolevulinic acid

Photodynamic therapy (PDT) is a relatively new therapy in dermatology that uses the topical application of a porphyrin derivative to selectively destroy a cutaneous target. The action is implemented by the application of a specific light frequency. The ability of porphyrin to selectively target tumor tissue has been known since the 1960s. In the late 1970s, the underlying mechanism was defined, and Dougherty’s discovery of the first chromophore led to the production and commercialization of Photofrin^®. Many other chromophores that can act as photosensitizers have been studied since then, with aminolevulinic acid currently the most commonly used chromophore in clinical practice. PDT is simple, minimally invasive and can be administered on an outpatient basis. The efficacy of PDT has been proven for actinic keratosis, Bowen’s disease and basal cell carcinoma; another of its well-known applications is the treatment of photoaging. Indications for its use are continuously increasing, and promising results are reported for various skin diseases. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence.

Effect of molecular characteristics on cellular uptake, subcellular localization, and phototoxicity of Zn(II) N-alkylpyridylporphyrins

Tetra-cationic Zn(II) meso-tetrakis(N-alkylpyridinium-2 (or -3 or -4)-yl)porphyrins (ZnPs) with progressively increased lipophilicity were synthesized to investigate how the tri-dimensional shape and lipophilicity of the photosensitizer (PS) affect cellular uptake, subcellular distribution, and photodynamic efficacy. The effect of the tri-dimensional shape of the molecule was studied by shifting the N-alkyl substituent attached to the pyridyl nitrogen from ortho to meta and para positions. Progressive increase of lipophilicity from shorter hydrophilic (methyl) to longer amphiphilic (hexyl) alkyl chains increased the phototoxicity of the ZnP PSs. PS efficacy was also increased for all derivatives when the alkyl substituents were shifted from ortho to meta, and from meta to para positions. Both cellular uptake and subcellular distribution of the PSs were affected by the lipophilicity and the position of the alkyl chains on the periphery of the porphyrin ring. Whereas the hydrophilic ZnPs demonstrated mostly lysosomal distribution, the amphiphilic hexyl derivatives were associated with mitochondria, endoplasmic reticulum, and plasma membrane. A comparison of hexyl isomers revealed that cellular uptake and partition into membranes followed the order para > meta > ortho. Varying the position and length of the alkyl substituents affects (i) the exposure of cationic charges for electrostatic interactions with anionic biomolecules and (ii) the lipophilicity of the molecule. The charge, lipophilicity, and the tri-dimensional shape of the PS are the major factors that determine cellular uptake, subcellular distribution, and as a consequence, the phototoxicity of the PSs.

[Botulinum toxin: the misguided path]

Botulinum toxin is widely used and has become a popular mass phenomenon in aesthetic medicine. Considerable scientific data concerning the biopsychosocial impact of botulinum toxin use have become available. The bidirectional interaction of mimic and emotion, described as the facial feedback hypothesis, is particularly influenced, as is mimicry. Furthermore, botulinum toxin can cause dysfunction of face harmony including false laughing or the "frozen face". As a result, complex psychosocial disturbances can occur and may affect social interaction and cause flattening of affect. Thus one must ask whether in the future botulinum toxin will continue to be employed in aesthetic dermatology or perhaps be regarded as a misguided path.