Simulations on the selectivity of 5-aminolaevulinic acid-induced fluorescence in vivo

Ackermann, Günther; Abels, Christoph; Bäumler, Wolfgang; Langer, Stefan; Landthaler, Míchael; Lang, Elmar; Szeimies, R.-M.

doi:10.1016/s1011-1344(98)00210-3

Cited by 38 publications

(29 citation statements)

References 24 publications

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“…The endogenous photosensitiser ALA is a haem precursor and induces the synthesis of porphyrins (protoporphyrin IX, PpIX) in mitochondria-containing cells (Williams, 1990). A selectivity of ALA-induced porphyrins is described in neoplastic tissue (Abels et al, 1994;Ackermann et al, 1998;Langer et al, 1999) as well as in malignant cells (Rittenhouse-Diakun et al, 1995) and provides the basis for clinical use of ALA-based photodynamic therapy and diagnosis (Kriegmair et al, 1995). ALA is water soluble and can therefore be administered either systemically (Grant et al, 1993) or topically (Szeimies et al, 1994).…”

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confidence: 99%

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

et al. 2003

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To improve efficacy of photodynamic therapy (PDT) with intravenously administered 5-aminolaevulinic acid (ALA) fractionating the light dose or reducing the light intensity may be a possibility. Therefore, Syrian Golden hamsters were fitted with dorsal skinfold chambers containing an amelanotic melanoma (n ¼ 26). PDT was performed (100 mW cm À2 , 100 J cm À2 , continuously or fractionated, and 25 mW cm À2 , 100 J cm À2 ; continuously or fractionated) using an incoherent light source following i.v. application of ALA. Following fractionated irradiation, the light was paused after 20 J cm À2 for 15 min. Prior to and up to 24 h after PDT tissue, pO 2 was measured using luminescence lifetime imaging. The efficacy was evaluated by measuring the tumour volume of amelanotic melanoma cells grown subcutaneously in the back of Syrian Golden hamsters (n ¼ 36). Only high-dose PDT resulted in a significant decrease of pO 2 . Irrespective of the mode of irradiation only high-dose PDT induced complete remission of all tumours (13 out of 13). It could be shown that low-dose PDT failed to induce a significant decrease of pO 2 . No significant effect of fractionated irradiation was shown regarding the therapeutic efficacy 28 days after PDT. Thus performing a fractionated PDT with ALA or reducing the light intensity seems not to be successful in clinical PDT according to the present data.

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confidence: 99%

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

et al. 2003

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“…In contrast, we found that FD was superior for non-PBCCs in this respect. The better correlation between fluorescence and microscopic margins in this study was probably attributable to a number of factors, including the specific clinical subtypes of the BCCs assessed and the longer period for which the photosensitiser was left on before the fluorescence margins were measured (3 vs 6 h) (28). However, surgical depth was not significantly different between the 2 groups for non-PBCCs.…”

Section: Discussionmentioning

confidence: 63%

Efficacy of Fluorescence Diagnosis-guided Mohs Micrographic Surgery for Pigmented vs Non-pigmented Basal Cell Carcinoma

Jeon¹,

Kim²,

Song³

2014

Acta Derm Venerol

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Pigmented basal cell carcinoma (PBCC) occurs more frequently in Asian population. The efficacy of fluorescence diagnosis (FD) for PBCCs treated with Mohs micrographic surgery has not yet been determined. This study enrolled 255 patients with 258 biopsy-proven BCC lesions: 199 PBCCs (77.1%) and 59 non-PBCCs (22.9%). We compared the clinicopathological and surgical features of the PBCCs and non-PBCCs. Each group was divided into 2 sub-groups, those assessed and not assessed by FD, to retrospectively analyse surgical features. Aggressive histological subtypes were less prevalent in PBCCs than in non-PBCCs. PBCCs required significantly fewer stages of Mohs excision, with significantly smaller surgical margins and surgical depth, than non-PBCCs. FD did not confer any benefits on PBCCs during Mohs micrographic surgery. However, non-PBCCs assessed by FD required significantly fewer Mohs stages, with significantly smaller surgical margins, than lesions not assessed by FD. These findings suggest that FD should be performed before Mohs micrographic surgery to delineate the margins of non-PBCCs in Asians.

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“…5-ALA is a prodrug that can be converted in situ into a highly fluorescent substance, protoporphyrin IX (PpIX), an effective photosensitizer by the heme biosynthetic pathway. The presence of exogenous 5-ALA bypasses feedback control, and thus may induce intracellular accumulation of photosensitizing concentrations of PpIX [3]. Topical photodynamic therapy using 5 aminolevulinic acid (5-ALA-PDT) has shown to be highly efficient for the topical treatment of a variety of superficial skin malignances [4]; it presents advantages over conventional treatments, like surgery, electrodessication, cryosurgery, topical application of podophylin or 5-fluorouracil, and radiotherapy [5].…”

Section: Introductionmentioning

confidence: 99%

Stratum corneum lipids liposomes for the topical delivery of 5-aminolevulinic acid in photodynamic therapy of skin cancer: preparation and in vitro permeation study

et al. 2001

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BackgroundPhotodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) is a skin cancer therapy that still has limitations due to the low penetration of this drug into the skin. We have proposed in this work a delivery system for 5-ALA based on liposomes having lipid composition similar to the mammalian stratum corneum (SCLLs) in order to optimize its skin delivery in Photodynamic Therapy (PDT) of skin cancers.MethodsSCLLs were obtained by reverse phase evaporation technique and size distribution of the vesicles was determinated by photon correlation spectroscopy. In vitro permeation profile was characterized using hairless mouse skin mounted in modified Franz diffusion cell.ResultsSize exclusion chromatography on gel filtration confirmed vesicle formation. SCLLs obtained by presented a degree of encapsulation of 5-ALA around 5.7%. A distribution of vesicle size centering at around 500 nm and 400 nm respectively for SCLLs and SCLLs containing 5-ALA was found. In vitro 5-ALA permeation study showed that SCLLs preparations presented higher skin retention significantly (p < 0.05) on the epidermis without SC + dermis, with a decreasing of skin permeation compared to aqueous solution.ConclusionsThe in vitro delivery performance provided by SCLLs lead to consider this systems adequate for the 5-ALA-PDT of skin cancer, since SCLLs have delivered 5-ALA to the target skin layers (viable epidermis + dermis) to be treated by topical PDT of skin cancer.

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Simulations on the selectivity of 5-aminolaevulinic acid-induced fluorescence in vivo

Cited by 38 publications

References 24 publications

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

Efficacy of Fluorescence Diagnosis-guided Mohs Micrographic Surgery for Pigmented vs Non-pigmented Basal Cell Carcinoma

Stratum corneum lipids liposomes for the topical delivery of 5-aminolevulinic acid in photodynamic therapy of skin cancer: preparation and in vitro permeation study

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