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Topical Photodynamic Therapy (topical + photodynamic_therapy)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Reduction in the Incidence of Squamous Cell Carcinoma in Solid Organ Transplant Recipients Treated with Cyclic Photodynamic Therapy

DERMATOLOGIC SURGERY, Issue 5 2010
ANDREA WILLEY MD
BACKGROUND AND OBJECTIVES Squamous cell carcinomas (SCCs) produce significant morbidity in solid organ transplant recipients (SOTRs), particularly in patients who develop multiple tumors. Topical photodynamic therapy (PDT) has been shown to decrease the number of keratotic lesions in SOTRs, but the duration of the beneficial effect is limited. The aim of this study was to evaluate the potential benefit of cyclic PDT in the prevention of new SCCs in SOTRs. METHODS Twelve high-risk SOTRs received cyclic PDT treatments at 4- to 8-week intervals for 2 years. The development of new SCCs (invasive and in situ) performed 12 and 24 months after the start of cyclic PDT were compared with the number of SCCs developed during the year before initiation of cyclic PDT. RESULTS The median reduction in the 12- and 24-month post-treatment counts from the 1-month pretreatment counts was 79.0% (73.3,81.8%) and 95.0% (87.5,100.0%), respectively. Treatments were well tolerated. CONCLUSION Cyclic PDT with 5-aminolevulinic acid may reduce the incidence of SCC in SOTRs. Additional studies with larger numbers of patients and optimized protocols are necessary to further explore the potential benefits of cyclic PDT in the prevention of skin cancer in this high-risk patient population. Dr. Lee is member of the Medical Advisory Board of Dusa Pharmaceuticals, Inc. [source]

Aesthetic effects of topical photodynamic therapy

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 11 2010
E Kohl
Abstract Topical photodynamic therapy has shown to be effective for the treatment of several aspects of skin ageing. Multiple studies have demonstrated improvement of fine wrinkles, mottled hyperpigmentation, tactile roughness and sallowness. These results are supported by immunohistochemical analysis that revealed both upregulation of collagen production and increased epidermal proliferation. Neocollagenesis as an indirect dermal effect of photodynamic therapy is stimulated through cytokine induction. This article reviews the available literature for photodynamic rejuvenation while discussing cosmetic effects, light sources, adverse effects and the mechanism of action. [source]

Topical photodynamic therapy with 5-aminolaevulinic acid does not induce hair regrowth in patients with extensive alopecia areata

BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2000
R. Bissonnette
Background,Photodynamic therapy (PDT) is a new modality involving the administration of a photosensitizer, or photosensitizer precursor, followed by its activation with light to generate a therapeutic effect. 5-Aminolaevulinic acid (ALA) is a photosensitizer precursor that is transformed by cells into protoporphyrin IX (PpIX), which can in turn be activated by red light. Objectives,To investigate the effect of PDT in alopecia areata (AA). Methods,In six patients with extensive AA, topical ALA lotion at 5%, 10% and 20% as well as the vehicle lotion alone were applied separately to different scalp areas, followed 3 h later by exposure to red light at each treatment session. Results,No significant hair growth was observed after 20 twice-weekly treatment sessions. A significant increase in erythema and pigmentation was observed for the three concentrations of ALA lotion vs. the vehicle, implying that a phototoxic PDT effect was achieved in the skin. In vivo fluorescence spectroscopy in one patient showed an increase in red PpIX fluorescence 3 h after ALA application followed by a decrease after light exposure. On fluorescence microscopy, bright red fluorescence was present in the epidermis and sebaceous glands, but not in the inflammatory infiltrate surrounding the hair follicle following ALA application. Conclusions,PDT was ineffective in the treatment of AA. [source]

New and emerging treatments in dermatology: acne

DERMATOLOGIC THERAPY, Issue 2 2008
A. Katsambas
ABSTRACT:, Topical retinoids, benzoyl peroxide, azelaic acid, and topical and oral antibiotics remain the milestone of treatment for mild to moderate acne vulgaris. Oral isotretinoin is useful for the treatment of severe nodular acne, treatment-resistant acne, and acne with a risk of physical or psychological scarring. Hormonal treatment in female acne is useful in resistant or late-onset acne. With increasing concerns regarding teratogenicity of isotretinoin and increasing antibiotic resistance, there is a clear need for therapeutic alternatives to these long-used treatments. Research in the pathogenesis of acne has allowed for new therapies and future perspectives regarding acne to evolve. They include low-dose long-term isotretinoin regimens, insulin-sensitizing agents, 5,-reductase type 1 inhibitors, topical photodynamic therapy, new combination formulations, dietary interventions, and antiinflammatory agents such as lipoxygenase inhibitors. [source]

Aminolevulinic acid-loaded Witepsol microparticles manufactured using a spray congealing procedure: implications for topical photodynamic therapy

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2009
Rasil Al-Kassas
Abstract Objectives The aim was to enhance aminolevulinic acid (ALA) stability by incorporation into low-melting microparticles prepared using a spray congealing procedure and to evaluate temperature-triggered release, allowing topical bioavailability following melting at skin temperature. Methods ALA-loaded Witepsol microparticles were prepared using a novel spray congealing technique. Entrapment efficiency was compared with conventional emulsion-based methods and modelled drug release profiles determined using a membrane separation technique. Raised receiver medium temperature was used to determine triggered release. Bioavailability and lipid-mediated enhancement of ALA penetration were determined in excised murine skin. Key findings ALA-loaded Witepsol microparticles were spherical, with a mean diameter of 20 ,m. Loading and stability studies demonstrated effective encapsulation, ranging from 91% to 100%, with no evidence of degradation to pyrazine derivatives. ALA release correlated with dissolution medium temperature, triggered at temperatures close to that of skin. Results suggested that molten Witepsol enhanced cutaneous permeation, whereas incorporation of microparticles in a semi-solid vehicle attenuated ALA penetration. Optimal use was direct application under occlusion. Conclusions Spray congealing is superior to the emulsion-based procedures with respect to encapsulation efficiency of ALA in Witepsol matrices, providing temperature-triggered release, enhanced stability and improved penetration of ALA through keratinised skin. These features could improve ALA delivery to superficial lesions as part of photodynamic therapy. [source]

Aesthetic effects of topical photodynamic therapy

Disappointing results and low tolerability of photodynamic therapy with topical 5-aminolaevulinic acid in psoriasis.

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2006
A randomized, double-blind phase I/II study
Abstract Background, Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. Objective, A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. Methods, In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm2 and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). Results, The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. Conclusion, Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. [source]

In vitro and in vivo comparison of two different light sources for topical photodynamic therapy

BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006
P. Babilas
Summary Background, Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is an effective and safe treatment option for the treatment of actinic keratosis (AK). Incoherent lamps are often used, matching the absorption maxima of ALA. Objectives, A comparative trial was performed to evaluate the efficacy of recently developed light-emitting diodes (LEDs). Methods, Human epidermal keratinocytes were incubated for 24 h with ALA (100, 200, 300, 400 or 500 ,mol L,1) and irradiated consecutively using either an incoherent halogen lamp (,em = 580,750 nm; 24 J cm,2; 40 mW cm,2) or an LED system (,em = 633 ± 3 nm; 3, 6, 12 or 24 J cm,2; 40 mW cm,2). Topical ALA-PDT was performed on 40 patients with AK (n = 584) in a symmetrical distribution suitable for two-sided comparison. After incubation with ALA (20% in cream base) irradiation was performed with the incoherent lamp (100 J cm,2; 160 mW cm,2) on one side and the LED system (40 J cm,2; 80 mW cm,2) on the opposite side followed by re-evaluation up to 6 months. Results, No significant differences between the LED system (3, 6, 12 or 24 J cm,2) and the incoherent light source (24 J cm,2) regarding cytotoxicity was found in vitro. The complete remission rate yielded in the in vivo investigation was also not significantly different at 6 weeks (P = 0·95), 3 months (P = 0·75) and 6 months (P = 0·61) following therapy. Six weeks following therapy complete remission rates of 84·3% (LED system) and 82·8% (incoherent lamp) were achieved. There was also no significant difference between both light sources regarding pain during light treatment (P = 0·67), patient satisfaction (P = 1·0) or cosmesis (P = 1·0) following therapy. Conclusions, These results show the efficacy of an LED system for ALA-PDT both in vitro and in vivo. ALA-PDT with the LED system showed a noninferiority regarding the clinical outcome in the treatment of AK compared with the incoherent lamp. [source]

Neoplasia treated by topical photodynamic therapy with variable irradiation dose and concentration of photosensitizer

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 7 2009
Q. Li
No abstract is available for this article. [source]