Photodynamic therapy in dermatology

Development of a novel laboratory photodynamic therapy device: automated multi-mode LED system for optimum well-plate irradiation

Photodynamic therapy (PDT) is a targeted treatment method that utilizes a photosensitizer (PS) to induce cytotoxicity in malignant and non-malignant tumors. Optimization of PDT requires investigation of the selectivity of PS for the target tissues, irradiating light source, irradiation wavelengths, fluence rate, fluence, illumination mode, and overall treatment plan. In this study, we developed the Multi-mode Automatized Well-plate PDT LED Laboratory Irradiation System (MAWPLIS), an innovative device that automates time-consuming well plate light dosage/PS dose measurement experiment. The careful control of LED current and temperature stabilization in the LED module allowed the system to achieve high optical output stability. The MAWPLIS was designed by integrating a 3-axis moving system and motion controller, a quick-switching LED controller unit equipped with interchangeable LED modules capable of employing multiple wavelengths, and a TEC system. The proposed system achieved high optical output stability (1 mW) within the range of 0-500 mW, high wavelength stability (5 nm) at 635 nm, and high temperature stability (0.2 °C) across all radiation modes. The system's validation involved in vitro analysis using 5-ALA across varying concentrations, incubation periods, light exposures, and wavelengths in HT-29 colon cancer and WI-38 human lung fibroblast cell lines. Specifically, a combination of 405 nm and 635 nm wavelengths was selected to demonstrate enhanced strategies for colon cancer cell eradication and system validation. The MAWPLIS system represents a significant advancement in photodynamic therapy (PDT) research, offering automation and standardization of time-intensive experiments, high stability and precision, and improved PDT efficacy through dual-wavelength integration.

Topical 5-aminolevulinic acid (ALA)-photodynamic therapy (PDT) for lichen sclerosus of face: case report and literature review

Lichen sclerosus (LS) is a chronic inflammatory dermatosis typical of the genital region, with rare involvement of extragenital areas and particularly the face. LS therapeutic management is challenging, and common therapies including topical and systemic corticosteroids, topical calcineurin inhibitors, surgery are often ineffective. Herein, we present a case of LS occurred in a 36-year-old girl with facial involvement resistant to therapy with systemic corticosteroids and topical tacrolimus. Considering the involvement of a sensitive area, the young age of the patient, and the consistent clinical experience in using photodynamic therapy for the treatment of facial skin disease, we started a treatment with topical 5-aminolevulinic acid (ALA)-photodynamic therapy (PDT) with a dosage of 37 J/cm2 once a month. We compared our case with eight other facial LS patients from the literature and treated differently.

A systematic computational study of acridine derivatives through conceptual density functional theory

A detailed computational analysis of acridine derivatives viz. acridone, 9-amino acridine hydrochloride hydrate, proflavin, acridine orange and acridine yellow is done in terms of conceptual density functional theory (CDFT). CDFT-based global descriptors-ionization potential, electron affinity, HOMO-LUMO gap, hardness, softness, electronegativity and electrophilicity index of acridine derivatives for ground state as well as excited state are estimated with the help of different hybrid functionals B3LYP/6-31G (d, p), B3LYP/6-311G (d, p), B3LYP/DGDZVP and B3LYP/LANL2DZ. Acridine derivatives show higher values of ionization potential and electron affinity in excited state as compared to ground state, indicating that these compounds are willing to accept electrons in excited state rather than donating electron. Acridone shows the maximum HOMO-LUMO energy gap in ground and excited state which implies that one-way electron transfer is most feasible with this compound. Our computed results emphasize the pronounced electron acceptor behaviour of the acridine derivatives in the excited state which has already been experimentally verified. It is observed that the trend in the computed values of the descriptors is not much improved on refinement of the basis set.

Interaction of Cyanine-D112 with Binary Lipid Mixtures: Molecular Dynamics Simulation and Differential Scanning Calorimetry Study

This comprehensive molecular dynamics (MD) simulation and experimental study investigates the lipid bilayer interactions of dye D112 for potential photodynamic therapy (PDT) applications. PDT involves formation of a reactive oxidant species in the presence of a light sensitive molecule and light, interrupting cellular functions. D112 was developed as a photographic emulsifier, and we hypothesized that its combined cationic and lipophilic nature can render a superior photosensitizing property-crucial in various light therapies. The focus of this study is to elucidate the binding and insertion mechanisms of D112 with mixed lipid bilayers of anionic dipalmitoyl-phosphatidylserine (DPPS) and zwitterionic dipalmitoyl-phosphatidylcholine (DPPC) lipids to resemble cancer cell membranes. Our studies confirm initial electrostatic binding between the positively charged moieties of D112 and negatively charged lipid headgroups. Additionally, MD simulations combined with differential scanning calorimetry (DSC) studies confirm that D112-lipid interactions are governed by enthalpy-driven nonclassical hydrophobic effects in the membrane interior. It was further noted that despite the electrostatic preference of D112 toward the anionic lipids, D112 molecules colocalized on DPPC-rich domains after insertion. Atomistic level MD studies point toward two possible insertion mechanisms for D112: harpoon and flip. Further insights from the simulation showcase the interactions of low and high aggregates of D112 with the bilayer as the concentration of D112 increases in solution. The size of aggregates modulates the orientation and degree of insertion, providing important information for future studies on membrane permeation mechanisms.

A wireless optoelectronic skin patch for light delivery and thermal monitoring

Wearable optoelectronic devices can interface with the skin for applications in continuous health monitoring and light-based therapy. Measurement of the thermal effect of light on skin is often critical to track physiological parameters and control light delivery. However, accurate measurement of light-induced thermal effects is challenging because conventional sensors cannot be placed on the skin without obstructing light delivery. Here, we report a wearable optoelectronic patch integrated with a transparent nanowire sensor that provides light delivery and thermal monitoring at the same location. We achieve fabrication of a transparent silver nanowire network with >92% optical transmission that provides thermoresistive sensing of skin temperature. By integrating the sensor in a wireless optoelectronic patch, we demonstrate closed-loop regulation of light delivery as well as thermal characterization of blood flow. This light delivery and thermal monitoring approach may open opportunities for wearable devices in light-based diagnostics and therapies.

Applications of Fluorous Porphyrinoids: An Update†

Porphyrins and related macrocycles have been studied broadly for their applications in medicine and materials because of their tunable physicochemical, optoelectronic and magnetic properties. In this review article, we focused on the applications of fluorinated porphyrinoids and their supramolecular systems and summarized the reports published on these chromophores in the past 5-6 years. The commercially available fluorinated porphyrinoids: meso-perfluorophenylporphyrin (TPPF₂₀ ) perfluorophthalocyanine (PcF₁₆ ) and meso-perfluorophenylcorrole (CorF₁₅ ) have increased photo and oxidative stability due to the presence of fluoro groups. Because of their tunable properties and robustness toward oxidative damage these porphyrinoid-based chromophores continue to gain attention of researchers developing advanced functional materials for applications such as sensors, photonic devices, component for solar cells, biomedical imaging, theranostics and catalysts.

Metal organic frameworks (MOFs) with therapeutic and biomedical applications: a patent review

Introduction: Metal organic frameworks (MOFs) are a recent group of nano porous materials with exceptional physical properties, such as large surface areas, high pore volumes, low densities and well-defined pores. This type of material has been used frequently for biomedical and therapeutic applications, such as drug delivery systems and theranostic materials.Areas covered: In this review, the authors searched for patents filed in the last 10 years, found in different databases, related to the therapeutic or biomedical application of MOFs for use in different health fields. The possibility of these new materials becoming new therapeutic possibilities available to the population was emphasized.Expert opinion: The advances in research with MOFs have grown in the last 10 years and with that many possibilities for their applications have emerged in several areas, especially biomedical. The possibility of using these materials in drug delivery systems is the most common form of possibility of use in the health area, mainly due to easy obtaining and high reproducibility, which are seen very positively by the drug development technology sector.

Interventions for basal cell carcinoma of the skin

BACKGROUND

Basal cell carcinoma (BCC) is the commonest cancer affecting white-skinned individuals, and worldwide incidence is increasing. Although rarely fatal, BCC is associated with significant morbidity and costs. First-line treatment is usually surgical excision, but alternatives are available. New published studies and the development of non-surgical treatments meant an update of our Cochrane Review (first published in 2003, and previously updated in 2007) was timely.

OBJECTIVES

To assess the effects of interventions for BCC in immunocompetent adults.

SEARCH METHODS

We updated our searches of the following databases to November 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and LILACS.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of interventions for BCC in immunocompetent adults with histologically-proven, primary BCC. Eligible comparators were placebo, active treatment, other treatments, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcome measures were recurrence at three years and five years (measured clinically) (we included recurrence data outside of these time points if there was no measurement at three or five years) and participant- and observer-rated good/excellent cosmetic outcome. Secondary outcomes included pain during and after treatment, early treatment failure within six months, and adverse effects (AEs). We used GRADE to assess evidence certainty for each outcome.

MAIN RESULTS

We included 52 RCTs (26 new) involving 6690 participants (median 89) in this update. All studies recruited from secondary care outpatient clinics. More males than females were included. Study duration ranged from six weeks to 10 years (average 13 months). Most studies (48/52) included only low-risk BCC (superficial (sBCC) and nodular (nBCC) histological subtypes). The majority of studies were at low or unclear risk of bias for most domains. Twenty-two studies were industry-funded: commercial sponsors conducted most of the studies assessing imiquimod, and just under half of the photodynamic therapy (PDT) studies. Overall, surgical interventions have the lowest recurrence rates. For high-risk facial BCC (high-risk histological subtype or located in the facial 'H-zone' or both), there may be slightly fewer recurrences with Mohs micrographic surgery (MMS) compared to surgical excision (SE) at three years (1.9% versus 2.9%, respectively) (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.16 to 2.64; 1 study, 331 participants; low-certainty evidence) and at five years (3.2% versus 5.2%, respectively) (RR 0.61, 95% CI 0.18 to 2.04; 1 study, 259 participants; low-certainty evidence). However, the 95% CI also includes the possibility of increased risk of recurrence and no difference between treatments. There may be little to no difference regarding improvement of cosmetic outcomes between MMS and SE, judged by participants and observers 18 months post-operatively (one study; low-certainty evidence); however, no raw data were available for this outcome. When comparing imiquimod and SE for nBCC or sBCC at low-risk sites, imiquimod probably results in more recurrences than SE at three years (16.4% versus 1.6%, respectively) (RR 10.30, 95% CI 3.22 to 32.94; 1 study, 401 participants; moderate-certainty evidence) and five years (17.5% versus 2.3%, respectively) (RR 7.73, 95% CI 2.81 to 21.3; 1 study, 383 participants; moderate-certainty evidence). There may be little to no difference in the number of participant-rated good/excellent cosmetic outcomes (RR 1.00, 95% CI 0.94 to 1.06; 1 study, 326 participants; low-certainty evidence). However, imiquimod may result in greater numbers of good/excellent cosmetic outcomes compared to SE when observer-rated (60.6% versus 35.6%, respectively) (RR 1.70, 95% CI 1.35 to 2.15; 1 study, 344 participants; low-certainty evidence). Both cosmetic outcomes were measured at three years. Based on one study of 347 participants with high- and low-risk primary BCC of the face, radiotherapy may result in more recurrences compared to SE under frozen section margin control at three years (5.2% versus 0%, respectively) (RR 19.11, 95% CI 1.12 to 325.78; low-certainty evidence) and at four years (6.4% versus 0.6%, respectively) (RR 11.06, 95% CI 1.44 to 84.77; low-certainty evidence). Radiotherapy probably results in a smaller number of good participant- (RR 0.76, 95% CI 0.63 to 0.91; 50.3% versus 66.1%, respectively) or observer-rated (RR 0.48, 95% CI 0.37 to 0.62; 28.9% versus 60.3%, respectively) good/excellent cosmetic outcomes compared to SE, when measured at four years, where dyspigmentation and telangiectasia can occur (both moderate-certainty evidence). Methyl-aminolevulinate (MAL)-PDT may result in more recurrences compared to SE at three years (36.4% versus 0%, respectively) (RR 26.47, 95% CI 1.63 to 429.92; 1 study; 68 participants with low-risk nBCC in the head and neck area; low-certainty evidence). There were no useable data for measurement at five years. MAL-PDT probably results in greater numbers of participant- (RR 1.18, 95% CI 1.09 to 1.27; 97.3% versus 82.5%) or observer-rated (RR 1.87, 95% CI 1.54 to 2.26; 87.1% versus 46.6%) good/excellent cosmetic outcomes at one year compared to SE (2 studies, 309 participants with low-risk nBCC and sBCC; moderate-certainty evidence). Based on moderate-certainty evidence (single low-risk sBCC), imiquimod probably results in fewer recurrences at three years compared to MAL-PDT (22.8% versus 51.6%, respectively) (RR 0.44, 95% CI 0.32 to 0.62; 277 participants) and five years (28.6% versus 68.6%, respectively) (RR 0.42, 95% CI 0.31 to 0.57; 228 participants). There is probably little to no difference in numbers of observer-rated good/excellent cosmetic outcomes at one year (RR 0.98, 95% CI 0.84 to 1.16; 370 participants). Participant-rated cosmetic outcomes were not measured for this comparison. AEs with surgical interventions include wound infections, graft necrosis and post-operative bleeding. Local AEs such as itching, weeping, pain and redness occur frequently with non-surgical interventions. Treatment-related AEs resulting in study modification or withdrawal occurred with imiquimod and MAL-PDT.

AUTHORS' CONCLUSIONS

Surgical interventions have the lowest recurrence rates, and there may be slightly fewer recurrences with MMS over SE for high-risk facial primary BCC (low-certainty evidence). Non-surgical treatments, when used for low-risk BCC, are less effective than surgical treatments, but recurrence rates are acceptable and cosmetic outcomes are probably superior. Of the non-surgical treatments, imiquimod has the best evidence to support its efficacy. Overall, evidence certainty was low to moderate. Priorities for future research include core outcome measures and studies with longer-term follow-up.

5-Aminolevulinic Acid-Induced Fluorescence in Focal Cortical Dysplasia: Report of 3 Cases

BACKGROUND

Three patients enrolled in a clinical trial of 5-aminolevulinic-acid (5-ALA)-induced fluorescence-guidance, which has been demonstrated to facilitate intracranial tumor resection, were found on neuropathological examination to have focal cortical dysplasia (FCD).

OBJECTIVE

To evaluate in this case series visible fluorescence and quantitative levels of protoporphyrin IX (PpIX) during surgery and correlate these findings with preoperative magnetic resonance imaging (MRI) and histopathology.

METHODS

Patients were administered 5-ALA (20 mg/kg) approximately 3 h prior to surgery and underwent image-guided, microsurgical resection of their MRI- and electrophysiologically identified lesions. Intraoperative visible fluorescence was evaluated using an operating microscope adapted with a commercially available blue light module. Quantitative PpIX levels were assessed using a handheld fiber-optic probe and a wide-field imaging spectrometer. Sites of fluorescence measurements were co-registered with both preoperative MRI and histopathological analysis.

RESULTS

Three patients with a pathologically confirmed diagnosis of FCD (Types 1b, 2a, and 2b) underwent surgery. All patients demonstrated some degree of visible fluorescence (faint or moderate), and all patients had quantitatively elevated concentrations of PpIX. No evidence of neoplasia was identified on histopathology, and in 1 patient, the highest concentrations of PpIX were found at a tissue site with marked gliosis but no typical histological features of FCD.

CONCLUSION

FCD has been found to be associated with intraoperative 5-ALA-induced visible fluorescence and quantitatively confirmed elevated concentrations of the fluorophore PpIX in 3 patients. This finding suggests that there may be a role for fluorescence-guidance during surgical intervention for epilepsy-associated FCD.

Photodynamic Therapy of Psoriasis Using Photosensitizers of Vegetable Origin

Psoriasis is an immune-mediated, chronic and recurrent inflammatory skin disease, prevalent worldwide, and represents an important burden in life quality of patients. The most common clinical variant is termed as psoriasis vulgaris or plaque psoriasis, which with an individualized and carefully monitored therapy can decrease the patients' morbidity and improving their life quality. The aim is to achieve disease control, minimize the adverse drug effects, and tailor the treatment to individual patient factors. Photodynamic therapy (PDT) is based on local or systemic administration of a non-toxic photosensitizer followed by irradiation with a particular wavelength to generate reactive oxygen species (ROS), mainly highly cytotoxic singlet oxygen (1O2). The generation of these species results in the attack to substrates involved in biological cycles causing necrosis and apoptosis of affected tissues. Photosensitizers are found in natural products and also obtained by partial syntheses from abundant natural starting compounds. They can be isolated at low cost and in large amounts from plants or algae. Therefore, this manuscript reviews the use of molecules from vegetal sources as photosensitizer agents for the PDT of psoriasis. Psoriasis pathogenesis, management and treatment were reviewed. PDT principles, fundamentals and utilization for the treatment of psoriasis were also discussed. Photosensitizers for PDT of psoriasis are also reviewed focusing on those from vegetal sources. Despite the PDT is utilized for the treatment of psoriasis, very little amount of photosensitizers from plant sources are utilized, such as chlorophyll derivatives and hypericin; however, other natural photosensitizers such as curcumin, could also be investigated. They could constitute a very important, safe and cheap alternative for the successful photodynamic treatment of psoriasis.

Probing the Hydrogen Bond Involving Acridone Trapped in a Hydrophobic Biological Nanocavity: Integrated Spectroscopic and Docking Analyses

Spectroscopic analyses reveal that acridone (AD) penetrates through the structure and enters the hydrophobic cavity of the protein β-lactoglobulin (βLG). Although the protein contains two tryptophan (Trp) residues, AD interacts with only one (Trp-19), which is authenticated by the appearance of a single isoemissive point in TRANES. Alteration in the secondary structure of the protein while AD pierces through βLG is evident from the circular dichroism spectroscopic study. The ground-state interaction between AD and βLG is proven from the UV-vis spectroscopic study and the static nature of quenching of intrinsic fluorescence of the protein by the ligand. The steady-state fluorescence study in varied temperatures indicates the involvement of hydrogen bonding in the ligand-protein interaction. Further, the time-resolved fluorescence anisotropy study gives a hint of the presence of a hydrogen bond in AD-βLG interaction, which possibly involves the rotamers of Trp-19. In fact, the idea of involvement of rotamers of Trp-19 is obtained from the increase in fluorescence lifetime of βLG in the presence of AD. The docking study agrees to the involvement of hydrogen bonding in AD-βLG interaction. The direct evidence of hydrogen bonding between Trp and AD is obtained from the laser flash photolysis studies where the signature of formation of ADH^• and Trp^• through hydrogen abstraction between Trp and AD, loosely bound through hydrogen bonding, gets prominence. Thus, binding of AD to βLG involves hydrogen bonding in a hydrophobic pocket of the protein.

Photosensitivity and cancer immune-targeted therapies

The novel group of immunological agents used for solid tumors has importantly improved the quality of life and the survival rate of oncologic patients. Compared to conventional chemotherapy agents, they are more effective and less toxic. However, adverse cutaneous effects are commonly observed, and in some cases, they may induce treatment discontinuation, with heavy impact on patient prognosis. Among these, photosensitive reactions, either phototoxic or photoallergic, are increasing. Much remains to be clarified on the understanding of their prevention, diagnosis, and management. We have reviewed the literature about photosensitive reactions occurring during oncologic immunotherapies. Early dermatological diagnosis and adequate management, with oncologist's cooperation, is fundamental.

Efficacy and safety of photodynamic therapy with amino-5-laevulinate nanoemulsion versus methyl-5-aminolaevulinate for actinic keratosis: A meta-analysis

BACKGROUND

Photodynamic therapy is an effective treatment for actinic keratosis. 5-aminolevulinic acid nanoemulsion (BF-200 ALA) and methyl-5-aminolevulinate (MAL) are both prodrugs for the treatment of actinic keratosis with photodynamic therapy. A comparison of the efficacy and safety between the drugs is critical for clinical practice.

OBJECTIVES

To investigate if photodynamic therapy in combination with BF-200 ALA is superior to photodynamic therapy with MAL for actinic keratosis.

METHODS

We performed a meta-analysis to investigate the combination of photodynamic therapy with BF-200 ALA and with MAL. The PubMed, Cochrane Library, Web of Science and EMBASE databases were searched to select eligible randomized controlled trials. Our search was conducted on April 1, 2019, and included the search terms "5-aminolevulinic acid nanoemulsion or BF-200 ALA", "methyl-5-aminolevulinate or methyl aminolaevulinate" and "actnic keratosis". Cochrane Risk of Bias Tool was used to estimate the risk of bias.

RESULTS

The meta-analysis consisted of 5988 actinic keratosis lesions in five eligible randomized controlled trials, with a total of 2953 actinic keratosis lesions treated with BF-200 ALA and 3035 actinic keratosis lesions treated with MAL. BF-200 ALA in combination with photodynamic therapy showed significantly higher overall complete clearance rates (RR: 1.07, 95% CI 1.02-1.12, p = 0.01) and 3 month complete clearance rates (RR: 1.09, 95% CI 1.06-1.12, p < 0.00001) compared to MAL. A subgroup analysis was performed for photodynamic therapy combined with BF-200 ALA, revealing increased complete clearance rates of grade II-III lesions in comparison with MAL (RR: 1.24, 95% CI 1.05-1.46, p = 0.01). Compared with MAL, the pooled relative risk for the meta-analysis for recurrence was 0.67 (95% CI 0.48-0.92, p = 0.01) at 12 month after BF-200 ALA treatment.

CONCLUSION

Photodynamic therapy with BF-200 ALA has a 9% better chance of complete clearance at 3 months and a 24% better chance of grade II-III lesions after treatment than with MAL for patients with actinic keratosis.

In vivo wireless photonic photodynamic therapy

An emerging class of targeted therapy relies on light as a spatially and temporally precise stimulus. Photodynamic therapy (PDT) is a clinical example in which optical illumination selectively activates light-sensitive drugs, termed photosensitizers, destroying malignant cells without the side effects associated with systemic treatments such as chemotherapy. Effective clinical application of PDT and other light-based therapies, however, is hindered by challenges in light delivery across biological tissue, which is optically opaque. To target deep regions, current clinical PDT uses optical fibers, but their incompatibility with chronic implantation allows only a single dose of light to be delivered per surgery. Here we report a wireless photonic approach to PDT using a miniaturized (30 mg, 15 mm³) implantable device and wireless powering system for light delivery. We demonstrate the therapeutic efficacy of this approach by activating photosensitizers (chlorin e6) through thick (>3 cm) tissues inaccessible by direct illumination, and by delivering multiple controlled doses of light to suppress tumor growth in vivo in animal cancer models. This versatility in light delivery overcomes key clinical limitations in PDT, and may afford further opportunities for light-based therapies.

Some activities of PorphyChem illustrated by the applications of porphyrinoids in PDT, PIT and PDI

Photodynamic therapy is an innovative approach to treat diverse cancers and diseases that involves the use of photosensitizing agents along with light of an appropriate wavelength to generate cytotoxic reactive oxygen species.

Light therapies for acne: abridged Cochrane systematic review including GRADE assessments

We undertook a Cochrane review of randomized controlled trials (RCTs) evaluating the effects of light-based interventions for acne vulgaris. We searched the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, LILACS, ISI Web of Science and grey literature sources (September 2015). We used the Grading of Recommendations Assessment, Development and Evaluation Working Group approach to assess the quality of evidence (QoE). We included 71 RCTs (4211 participants, median sample size 31). Results from a single study (n = 266, low QoE) showed little or no difference in effectiveness on participants' assessment of improvement between 20% aminolaevulinic acid (ALA) photodynamic therapy (PDT), activated by blue light, vs. vehicle plus blue light, whereas another study (n = 180) comparing ALA-PDT (red light) concentrations showed that 20% ALA-PDT was no more effective than 15% ALA-PDT but better than 10% and 5% ALA-PDT. Pooled data from three studies (n = 360, moderate QoE) showed that methyl aminolaevulinate PDT, activated by red light, had a similar effect on changes in lesion counts vs. placebo cream with red light. Several studies compared yellow light with placebo or no treatment, infrared light with no treatment, gold microparticle suspension with vehicle and clindamycin/benzoyl peroxide (C/BPO) combined with pulsed dye laser with C/BPO alone. None of these showed any clinically significant effects. Most studies reported adverse effects, but inadequately, with scarring reported as absent, and blistering only in studies on intense pulsed light, infrared light and PDT (very low QoE). Carefully planned studies, using standardized outcome measures and common acne treatments as comparators, are needed.

Acridone in a biological nanocavity: detailed spectroscopic and docking analyses of probing both the tryptophan residues of bovine serum albumin

AD initially gets hooked to Trp 212 housed in domain IIA, inducing conformational changes in the protein and paving the way for the ligand to reach Trp 134 located in domain IB.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Clinical comparison of salicylic acid peel and LED-Laser phototherapy for the treatment of Acne vulgaris in teenagers

Acne vulgaris treatments usually cause sensitivity, teratogenicity and bacterial resistance. Investigations of other therapeutic techniques, such as phototherapy, are highly relevant. Thus, we compared the effectiveness of two Acne vulgaris treatments in adolescents: peeling with salicylic acid (SA) and phototherapy. Teens were randomly divided into: group I, treatment with SA peels (10%) and group II, treatment with phototherapy (blue LED and red laser lights). Photographs were taken before and after ten sessions of each treatment, carried out weekly, and compared. To compare the differences between the treatments, the Student t-test was used. P values < 0.05 were considered significant. Both techniques are effective therapies for the treatment of acne in teenagers since the number of comedones, papules and pustules decreased significantly at the end of the session. However, when the two treatments were compared, phototherapy showed a significant difference in reducing the number of pustules. The combined use of red and blue lights due to their anti-inflammatory and wound-healing properties is a more efficient alternative for treating Acne vulgaris in relation to SA and proves more reliable and without side effects, improving the adolescents' skin health.

Light therapies for acne

BACKGROUND

Acne vulgaris is a very common skin problem that presents with blackheads, whiteheads, and inflamed spots. It frequently results in physical scarring and may cause psychological distress. The use of oral and topical treatments can be limited in some people due to ineffectiveness, inconvenience, poor tolerability or side-effects. Some studies have suggested promising results for light therapies.

OBJECTIVES

To explore the effects of light treatment of different wavelengths for acne.

SEARCH METHODS

We searched the following databases up to September 2015: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase and LILACS. We searched ISI Web of Science and Dissertation Abstracts International (from inception). We also searched five trials registers, and grey literature sources. We checked the reference lists of studies and reviews and consulted study authors and other experts in the field to identify further references to relevant randomised controlled trials (RCTs). We updated these searches in July 2016 but these results have not yet been incorporated into the review.

SELECTION CRITERIA

We included RCTs of light for treatment of acne vulgaris, regardless of language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 71 studies, randomising a total of 4211 participants.Most studies were small (median 31 participants) and included participants with mild to moderate acne of both sexes and with a mean age of 20 to 30 years. Light interventions differed greatly in wavelength, dose, active substances used in photodynamic therapy (PDT), and comparator interventions (most commonly no treatment, placebo, another light intervention, or various topical treatments). Numbers of light sessions varied from one to 112 (most commonly two to four). Frequency of application varied from twice daily to once monthly.Selection and performance bias were unclear in the majority of studies. Detection bias was unclear for participant-assessed outcomes and low for investigator-assessed outcomes in the majority of studies. Attrition and reporting bias were low in over half of the studies and unclear or high in the rest. Two thirds of studies were industry-sponsored; study authors either reported conflict of interest, or such information was not declared, so we judged the risk of bias as unclear.Comparisons of most interventions for our first primary outcome 'Participant's global assessment of improvement' were not possible due to the variation in the interventions and the way the studies' outcomes were measured. We did not combine the effect estimates but rated the quality of the evidence as very low for the comparison of light therapies, including PDT to placebo, no treatment, topical treatment or other comparators for this outcome. One study which included 266 participants with moderate to severe acne showed little or no difference in effectiveness for this outcome between 20% aminolevulinic acid (ALA)-PDT (activated by blue light) versus vehicle plus blue light (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.72 to 1.04, low-quality evidence). A study (n = 180) of a comparison of ALA-PDT (activated by red light) concentrations showed 20% ALA was no more effective than 15% (RR 1.05, 95% CI 0.96 to 1.15) but better than 10% ALA (RR 1.22, 95% CI 1.05 to 1.42) and 5% ALA (RR 1.47, 95% CI 1.19 to 1.81). The number needed to treat for an additional beneficial outcome (NNTB) was 6 (95% CI 3 to 19) and 4 (95% CI 2 to 6) for the comparison of 20% ALA with 10% and 5% ALA, respectively.For our second primary outcome 'Investigator-assessed changes in lesion counts', we combined three RCTs, with 360 participants with moderate to severe acne and found methyl aminolevulinate (MAL) PDT (activated by red light) was no different to placebo cream plus red light with regard to change in inflamed lesions (ILs) (mean difference (MD) -2.85, 95% CI -7.51 to 1.81), percentage change in ILs (MD -10.09, 95% CI -20.25 to 0.06), change in non-inflamed lesions (NILs) (MD -2.01, 95% CI -7.07 to 3.05), or in percentage change in NILs (MD -8.09, 95% CI -21.51 to 5.32). We assessed the evidence as moderate quality for these outcomes meaning that there is little or no clinical difference between these two interventions for lesion counts.Studies comparing the effects of other interventions were inconsistent or had small samples and high risk of bias. We performed only narrative synthesis for the results of the remaining trials, due to great variation in many aspects of the studies, poor reporting, and failure to obtain necessary data. Several studies compared yellow light to placebo or no treatment, infrared light to no treatment, gold microparticle suspension to vehicle, and clindamycin/benzoyl peroxide combined with pulsed dye laser to clindamycin/benzoyl peroxide alone. There were also several other studies comparing MAL-PDT to light-only treatment, to adapalene and in combination with long-pulsed dye laser to long-pulsed dye laser alone. None of these showed any clinically significant effects.Our third primary outcome was 'Investigator-assessed severe adverse effects'. Most studies reported adverse effects, but not adequately with scarring reported as absent, and blistering reported only in studies on intense pulsed light, infrared light and photodynamic therapies. We rated the quality of the evidence as very low, meaning we were uncertain of the adverse effects of the light therapies.Although our primary endpoint was long-term outcomes, less than half of the studies performed assessments later than eight weeks after final treatment. Only a few studies assessed outcomes at more than three months after final treatment, and longer-term assessments are mostly not covered in this review.

AUTHORS' CONCLUSIONS

High-quality evidence on the use of light therapies for people with acne is lacking. There is low certainty of the usefulness of MAL-PDT (red light) or ALA-PDT (blue light) as standard therapies for people with moderate to severe acne.Carefully planned studies, using standardised outcome measures, comparing the effectiveness of common acne treatments with light therapies would be welcomed, together with adherence to the Consolidated Standards of Reporting Trials (CONSORT) guidelines.

Resistance of Nonmelanoma Skin Cancer to Nonsurgical Treatments. Part II: Photodynamic Therapy, Vismodegib, Cetuximab, Intralesional Methotrexate, and Radiotherapy

A wide range of treatments is now available for nonmelanoma skin cancer, including 5-fluorouracil, ingenol mebutate, imiquimod, diclofenac, photodynamic therapy, methotrexate, cetuximab, vismodegib, and radiotherapy. All are associated with high clinical and histologic response rates. However, some tumors do not respond due to resistance, which may be primary or acquired. Study of the resistance processes is a broad area of research that aims to increase our understanding of the nature of each tumor and the biologic features that make it resistant, as well as to facilitate the design of new therapies directed against these tumors. In this second article, having covered the topical treatments of nonmelanoma skin cancer, we review resistance to other nonsurgical treatments, such as monoclonal antibodies against basal and squamous cell carcinomas, intralesional chemotherapy, photodynamic therapy, and radiotherapy.

In situ production of ROS in the skin by photodynamic therapy as a powerful tool in clinical dermatology

Photodynamic therapy (PDT) is a clinical modality of photochemotherapy based on the accumulation of a photosensitizer in target cells and subsequent irradiation of the tissue with light of adequate wavelength promoting reactive oxygen species (ROS) formation and cell death. PDT is used in several medical specialties as an organ-specific therapy for different entities. In this review we focus on the current dermatological procedure of PDT. In the most widely used PDT protocol in dermatology, ROS production occurs by accumulation of the endogenous photosensitizer protoporphyrin IX after treatment with the metabolic precursors 5-methylaminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA). To date, current approved dermatological indications of PDT include actinic keratoses (AK), basal cell carcinoma (BCC) and in situ squamous cell carcinoma (SCC) also known as Bowen disease (BD). With regards to AKs, PDT can also treat the cancerization field carrying an oncogenic risk. In addition, an increasing number of pathologies, such as other skin cancers, infectious, inflammatory or pilosebaceous diseases are being considered as potentially treatable entities with PDT. Besides the known therapeutic properties of PDT, there is a modality used for skin rejuvenation and aesthetic purposes defined as photodynamic photorejuvenation. This technique enables the remodelling of collagen, which in turn prevents and treats photoaging stygmata. Finally we explore a new potential treatment field for PDT determined by the activation of follicular bulge stem cells caused by in situ ROS formation.

Photodynamic therapy with 5-aminolaevulinic acid and DNA damage: unravelling roles of p53 and ABCG2

OBJECTIVES

In spite of high sensitivity of A549 cells (p53(+/+) ) to lethal effects of photodynamic therapy with 5-aminolaevulinic acid (5-ALA/PDT), DNA damage was observed only in H1299 cells (p53(-/-) ), suggesting that p53 may exert a protective effect. Studies on human colon adenocarcinoma cell lines HCT-116, and their cognate knockouts for p53, were not entirely consistent with the assumption above. Exploring alternative explanations for such conflicting behaviour, we observed that expression of the ATP-binding cassette G2 (ABCG2), a regulator of cell component efflux, had important effects on PDT-generated DNA injury in PC3 cells (prostate) which are p53(-/-) and positive for ABCG2. Addition of an ABCG2 inhibitor in ABCG2 positive A549 (p53(+/+) ) and PC3 (p53(-/-) ) cells eliminated resistance to DNA damage.

MATERIALS AND METHODS

All cell lines investigated were incubated with 5-ALA and irradiated. Effects of PDT were evaluated assessing residual cell viability, cell-cycle profiles, PpIX localization, comet assay and Western blotting. Identical measurements were made in the presence of ABCG2 inhibitor, in cells expressing the transporter.

RESULTS

Our data show that cell aptitude to defend its DNA from PDT-induced injury was mainly ruled by ABCG2 expression. These findings, while providing helpful information in predicting effectiveness of 5-ALA/PDT, may indicate a way to shift PDT from a palliative to a more effective approach in anti-cancer therapy.

Fluorinated porphyrinoids as efficient platforms for new photonic materials, sensors, and therapeutics

Porphyrinoids are robust heterocyclic dyes studied extensively for their applications in medicine and as photonic materials because of their tunable photophysical properties, diverse means of modifying the periphery, and the ability to chelate most transition metals. Commercial applications include their use as phthalocyanine dyes in optical discs, porphyrins in photodynamic therapy, and as oxygen sensors. Most applications of these dyes require exocyclic moieties to improve solubility, target diseases, modulate photophysical properties, or direct the self-organization into architectures with desired photonic properties. The synthesis of the porphyrinoid depends on the desired application, but the de novo synthesis often involves several steps, is time consuming, and results in low isolated yields. Thus, the application of core porphyrinoid platforms that can be rapidly and efficiently modified to evaluate new molecular architectures allows researchers to focus on the design concepts rather than the synthesis methods, and opens porphyrinoid chemistry to a broader scientific community. We have focused on several widely available, commercially viable porphyrinoids as platforms: meso-perfluorophenylporphyrin, perfluorophthalocyanine, and meso-perfluorophenylcorrole. The perfluorophenylporphyrin is readily converted to the chlorin, bacteriochlorin, and isobacteriochlorin. Derivatives of all six of these core platforms can be efficiently and controllably made via mild nucleophilic aromatic substitution reactions using primary S, N, and O nucleophiles bearing a wide variety of functional groups. The remaining fluoro groups enhance the photo and oxidative stability of the dyes and can serve as spectroscopic signatures to characterize the compounds or in imaging applications using (19)F NMR. This review provides an overview of the chemistry of fluorinated porphyrinoids that are being used as a platform to create libraries of photo-active compounds for applications in medicine and materials.

Combined Treatments with Photodynamic Therapy for Non-Melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the Caucasian population. Among NMSC types, basal cell carcinoma (BCC) has the highest incidence and squamous cell carcinoma (SCC) is less common although it can metastasize, accounting for the majority of NMSC-related deaths. Treatment options for NMSC include both surgical and non-surgical modalities. Even though surgical approaches are most commonly used to treat these lesions, Photodynamic Therapy (PDT) has the advantage of being a non-invasive option, and capable of field treatment, providing optimum cosmetic outcomes. Numerous clinical research studies have shown the efficacy of PDT for treating pre-malignant and malignant NMSC. However, resistant or recurrent tumors appear and sometimes become more aggressive. In this sense, the enhancement of PDT effectiveness by combining it with other therapeutic modalities has become an interesting field in NMSC research. Depending on the characteristics and the type of tumor, PDT can be applied in combination with immunomodulatory (Imiquimod) and chemotherapeutic (5-fluorouracil, methotrexate, diclofenac, or ingenol mebutate) agents, inhibitors of some molecules implicated in the carcinogenic process (COX2 or MAPK), surgical techniques, or even radiotherapy. These new strategies open the way to a wider improvement of the prevention and eradication of skin cancer.

Spectroscopic exploration of drug–protein interaction: a study highlighting the dependence of the magnetic field effect on inter-radical separation distance formed during photoinduced electron transfer

The magnetic field effect can be used as a “spectroscopic ruler” to assess inter-radical separation distances in photoinduced electron transfer.

Photodynamic therapy in the treatment of basal cell carcinoma: a systematic review and meta-analysis

BACKGROUND/PURPOSE

This meta-analysis was designed to compare the efficacy, cosmetic outcome and safety of photodynamic therapy (PDT) with other procedures for the treatment of primary basal cell carcinoma (BCC).

METHODS

A computerized search through electronic databases was performed to search for relevant randomized controlled trials (RCTs) published before October 2013. Only RCTs that compared PDT to non-PDT for patients with BCC were selected. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Eight studies with a total of 1583 patients met the inclusion criteria. PDT was associated with lower complete clearance rate (RR: 0.93, 95% CI: 0.89-0.98), higher 1-year recurrence rate (RR: 12.42, 95% CI: 2.34-66.02) and 5-year recurrence rate (RR: 6.79, 95% CI: 2.43-18.96) when compared with surgical excision. There was no statistically significant difference in complete clearance rate (RR: 0.92, 95% CI: 0.85-1.00), 1-year recurrence rate (RR: 1.04, 95% CI: 0.46 to 2.39) or 5-year recurrence rate (RR: 1.08, 95% CI: 0.62-1.86) when PDT was compared with cryotherapy. PDT had higher complete clearance rate compared with placebo but no statistically significant difference in complete clearance rate and 1-year recurrence rate when compared with pharmacologic treatment (topical imiquimod and 5-fluorouracil). PDT had a significantly better cosmetic outcome than surgery and cryotherapy.

CONCLUSIONS

PDT is a useful method for the treatment of BCC, more efficient than placebo and with a similar efficiency to cryosurgery and pharmacologic treatment. Even though it is less effective than surgical excision, PDT has cosmetic advantages over surgery and cryosurgery.

Effect of photodynamic therapy on the skin using the ultrashort laser ablation

Photodynamic Therapy (PDT) with 5-aminolevulinic acid (ALA) is known to be limited for applications in tumours of large volume mainly due to the limited penetration of topical photosensitization. The results show that micro-holes created using a femtosecond laser before PDT significantly increased the depth of PDT effect in the healthy tissue. The combination of ultrashort laser ablation technique with PDT showed an important scientific breakthrough related to transportation and delivery of drugs into the deeper regions of the tissue.

Real-time analysis of endogenous protoporphyrin IX fluorescence from δ-aminolevulinic acid and its derivatives reveals distinct time- and dose-dependent characteristics in vitro

Photodynamic therapy (PDT) and photodiagnosis based on the intracellular production of the photosensitizer protoporphyrin IX (PPIX) by administration of its metabolic precursor -aminolevulinic acid (ALA) achieved their breakthrough upon the clinical approval of MAL (ALA methyl ester) and HAL (ALA hexyl ester). For newly developed ALA derivatives or application in new tumor types, in vitro determination of PPIX formation involves multiparametric experiments covering variable pro-drug concentrations, medium composition, time points of analysis, and cell type(s). This study uses a fluorescence microplate reader with a built-in temperature and atmosphere control to investigate the high-resolution long-term kinetics (72 h) of cellular PPIX fueled by administration of either ALA, MAL, or HAL for each 10 different concentrations. For simultaneous proliferation correction, A431 cells were stably transfected with green fluorescent protein. The results indicate that the peak PPIX level is a function of both, incubation concentration and period: maximal PPIX is generated with 1 to 2-mM ALA/MAL or 0.125-mM HAL; also, the PPIX peak shifts to longer incubation periods with increasing pro-drug concentrations. The results underline the need for detailed temporal analysis of PPIX formation to optimize ALA (derivative)-based PDT or photodiagnosis and highlight the value of environment-controlled microplate readers for automated in vitro analysis.

Aminolevulinic acid photodynamic therapy: medical evidence for its expanded use

Photodynamic therapy (PDT) has gained much popularity over the past several years as clinicians and researchers have expanded upon its indications and how one should utilize PDT in everyday practice. PDT is not a new field within dermatology or medicine in general, but for all practical reasons, PDT is considered to still be in its infancy. This article will review the history of PDT, explore PDT in both the US and European market place, and show how PDT is best utilized today in the USA. Finally, future ideas/thoughts on where PDT is heading will be surmised.

Interventions for non-metastatic squamous cell carcinoma of the skin: systematic review and pooled analysis of observational studies

OBJECTIVES

To assess the effects of treatments for non-metastatic invasive squamous cell carcinoma (SCC) of the skin using evidence from observational studies, given the paucity of evidence from randomised controlled trials.

DESIGN

Systematic review of observational studies.

DATA SOURCES

Medline, Embase, to December 2012.

REVIEW METHODS

Observational studies of interventions for primary, non-metastatic, invasive, SCC of the skin that reported recurrence during follow-up, quality of life, initial response to treatment, adverse events, cosmetic appearance, or death from disease. Studies were excluded if data for primary cutaneous SCC was not separable from other data. Data were extracted independently by two reviewers. Meta-analysis was performed where appropriate using a random effects model to estimate the pooled proportion of an event with 95% confidence intervals.

RESULTS

118 publications were included, covering seven treatment modalities. Pooled estimates of recurrence of SCCs were lowest after cryotherapy (0.8% (95% confidence interval 0.1% to 2%)) and curettage and electrodesiccation (1.7% (0.5% to 3.4%)), but most treated SCCs were small, low risk lesions. After Mohs micrographic surgery, the pooled estimate of local recurrence during variable follow-up periods from 10 studies was 3.0% (2.2% to 3.9%), which was non-significantly lower than the pooled average local recurrence of 5.4% (2.5% to 9.1%) after standard surgical excision (12 studies), and 6.4% (3.0% to 11.0%) after external radiotherapy (7 studies). After an apparently successful initial response of SCCs to photodynamic therapy, pooled average recurrence of 26.4% (12.3% to 43.7%; 8 studies) was significantly higher than other treatments. Evidence was limited for laser treatment (1 study) and for topical and systemic treatments (mostly single case reports or small non-comparative series with limited follow-up).

CONCLUSIONS

Many observational studies have looked at different treatment modalities for SCC, but the evidence base for the effectiveness of these interventions is poor. Comparison of outcomes after different treatments should be interpreted cautiously owing to biases inherent in the types of study included, and lack of direct comparisons to enable the estimation of relative treatment effect. Further evidence is needed to develop a prognostic model and stratify individuals at high risk of developing SCC, to improve the evidence base for this common cancer and to optimise clinical management.

PROTOCOL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42011001450.

Squamous Cell Carcinoma of the Eyelid Treated with Photodynamic Therapy

The ocular tissues can be the site of a number of malignant tumors in adults. Approximately 5% to 10% of all skin tumors occur in the eyelid. Incidence studies indicate that basal cell carcinoma is the most frequent malignant eyelid tumor (90%) followed by squamous cell carcinoma (9%). A 55-year-old man presented a squamous cell carcinoma (SCC) of 8 mm diameter, localized in the middle third of the lower eyelid, 3 mm under the eyelid margin on the eyelids. The histopathologic examination of a biopsy specimen showed the typical features of squamous cell carcinoma. Photodynamic therapy (PDT) with topical 5-aminolevulic acid (ALA) after Frost suture was employed. Very good results were obtained with rapid healing, without invasiveness, and without anesthesia. There was no evidence of scar formation and no signs of recurrence at 6 months follow-up. Many therapeutic methods have been suggested for squamous cell carcinoma of the eyelid. We consider photodynamic treatment of eyelid skin malignancies to be of great interest and it may represent an interesting future perspective for their management especially when surgical intervention cannot be tolerated by the patient.

Facial basal cell carcinomas recurring after photodynamic therapy: a retrospective analysis of histological subtypes

BACKGROUND

Photodynamic therapy (PDT) is an established treatment for basal cell carcinomas (BCCs). Although recurrences are sometime observed, their histological patterns have never been specifically studied or compared with the one of the initial tumor.

OBJECTIVE

To compare the histopathological aggressiveness of BCCs recurring after PDT with that of the primary tumors.

METHODS

The study population included 12 patients with 16 post PDT recurrent BCCs. Outcome measures were proportion of histologically aggressive subtypes in BCC recurrences vs. primary tumor.

RESULTS

62.5% of recurrent BCCs displayed a transition from a non-aggressive to an aggressive subtype.

CONCLUSIONS

Post PDT recurrences appear to display an increased histological aggressiveness, although the latter may reflect the natural course of tumor progression. Despite the presence of potential biases, our study raises the possibility that PDT favors the selection of more aggressive tumor cells. Better systematic large-scale follow-up studies are required to assess the exact frequency and histological types of BCC recurrences after PDT.

Photodynamic therapy can improve warts' discomfort in renal transplant patients prospective multicenter study

Many studies have been conducted showing that aminolevulinic acid (ALA)-photodynamic therapy (PDT) can be an alternative treatment for recalcitrant warts. Recently, we performed a study evaluating methyl-aminolevulinic acid (MAL)-PDT for the treatment of hand warts in a population of renal transplant patients. Two symmetrical targets were selected on each hand and randomly assigned to chemical keratolytic treatment followed by three cycles of ALA-PDT (75 J cm(-2) red light). Patients were evaluated after 3 months and a second run of PDT was performed if the total area and number of warts decreased less than 50%, with evaluation every 3 months for 1 year. Twenty patients were included and 16 were evaluable (9 M, 7 F). After 6 months the reduction of warts' area was 48.4% on the treated side versus 18.4% in the control area (P = 0.021). The decrease in the total number of warts was 41%versus 19.4% (P = NS). The global tolerance of the treatment was good with acceptable pain during irradiation. These results suggest that ALA-PDT is a safe and efficient treatment for transplanted patient warts. The improvement between treated and control zone is 20% due to the decrease in untreated warts' area and number.

The effect of increasing fluence on the treatment of actinic keratosis and photodamage by photodynamic therapy with 5-aminolevulinic acid and intense pulsed light

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) and intense pulsed light (IPL) is a relatively new combination for the treatment of actinic keratosis (AK) and photodamage. The objective of this study was to determine the effect of increasing the fluence of IPL on the outcome of patients with these skin conditions.

METHODS

Patients (N = 24) were randomly assigned to five treatment treatment groups: control (IPL alone) and ALA with 20, 25, 40, and 50  J/cm(2) fluence of IPL. Each patient received a single treatment. ALA was applied twice and allowed to incubate 2  h before IPL irradiation. Results were evaluated 5-7 days and 8 weeks after treatment. Clearance of AK lesions was evaluated by counting lesions before and after treatment, and improvement in photodamage was assessed by comparing pre- and post-treatment photographs. Statistical evaluation was based at nonparametric tests with a cut-off level at p < 0.10 and a confidence interval at 95%.

RESULTS

Responses to treatment were greatest in patients who received ALA and IPL fluences of 40 and 50  J/cm(2). Responses were "marked" in 19% of the patients receiving 50  J and "moderate" in 19% of the patients receiving 40  J. Compared to the mean pre-treatment AK grades, the mean post-treatment grades were 56% lower in the 50  J treatment group, 32% lower in the 25  J group, 50% lower in the 40  J group, 20% lower in the 20  J group, and 7% lower in the control group. Erythema, edema, crusts and erosion, and pain did not cause any patient to discontinue the study.

CONCLUSION

AK clearance, but not photorejuvenation, appears to improve with increasing fluence at the ALA PDT-IPL levels used in this study without serious adverse effects.

Determination of the tumor tissue optical properties during and after photodynamic therapy using inverse Monte Carlo method and double integrating sphere between 350 and 1000 nm

Photodynamic therapy (PDT) efficacy depends on the amount of light distribution within the tissue. However, conventional PDT does not consider the laser irradiation dose during PDT. The optical properties of biological tissues (absorption coefficient μ(a), reduced scattering coefficient μ's), anisotropy factor g, refractive index, etc.) help us to recognize light propagation through the tissue. The goal of this paper is to acquire the knowledge of the light propagation within tissue during and after PDT with the optical property of PDT-performed mouse tumor tissue. The optical properties of mouse tumor tissues were evaluated using a double integrating sphere setup and the algorithm based on the inverse Monte Carlo method in the wavelength range from 350 to 1000 nm. During PDT, the μ(a) and μ's were not changed after 1 and 5 min of irradiation. After PDT, the μ's in the wavelength range from 600 to 1000 nm increased with the passage of time. For seven days after PDT, the μ's increased by 1.7 to 2.0 times, which results in the optical penetration depth decreased by 1.4 to 1.8 times. To ensure an effective procedure, the adjustment of laser parameters for the decreasing penetration depth is recommended for the re-irradiation of PDT.