- New 5-Aminolevulinic Acid Esters-Efficient Protoporphyrin Precursors for Photodetection and Photodynamic Therapy
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Photodetection (PD) and photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) accumulation are approaches to detect and treat dysplasia and early cancer in the gastrointestinal tract and in the urinary bladder. Because ALA-induced PPIX production is limited, we synthesized ALA ester hydrochlorides 3-22 and tested them in two different in vitro models (gastrointestinal tract: HT29-CCD18; urinary bladder: J82-UROTSA). PPIX accumulation after incubation with 0.12 mmol/L for 3 h and PPIX accumulation as a function of different incubation times were measured using flow cytometry. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were performed to check cellular dark toxicity. Phototoxicity after irradiation was tested. ALA nonafluorohexylester hydrochloride 11, ALA thiohexylester hydrochloride 13 and ALA dibenzyldiester dihydrochloride 19 induced appreciably increased PPIX levels and showed improved phototoxicity compared with the references ALA hydrochloride 1, ALA hexylester hydrochloride 3 and ALA benzylester hydrochloride 4. Thus, the new compounds 11, 13 and 19 are promising compounds for PD and PDT.
- Brunner,Hausmann,Knuechel
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- Synthesis and evaluation of new 5-aminolevulinic acid derivatives as prodrugs of protoporphyrin for photodynamic therapy
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Protoporphyrin IX (PpIX) is used as a photosensitizer in the photodynamic diagnosis (PDD) and photodynamic therapy (PDT) of cancer and is synthesized intracellularly from 5-aminolevulinic acid (5-ALA) precursors. Thirteen novel 5-ALA derivatives were designed and synthesized appropriately with tailored hydrophilicity and lipophilicity. The generation of PpIX was detected and their antitumor activity in vitro and in vivo was also investigated. It was shown that compounds 9b-c, 11b-c and 13a displayed a characteristic long wavelength absorption peak at 593 nm after 5 h incubation in mice fibrosarcoma S180 cells. After being exposed to 600 nm laser light irradiation, these compounds can inhibit cell proliferation in S180 cells in vitro. The growth of S180 cell tumors in Kunming mice was significantly inhibited by these compounds in vivo. Among these compounds, 13a has low dark toxicity and high phototoxicity, which makes it an effective and promising prodrug for PDT.
- Zhu, Wei,Gao, Ying-Hua,Song, Chun-Hong,Lu, Zhi-Bin,Namulinda, Tabbisa,Han, Yi-Ping,Yan, Yi-Jia,Wang, Lai-Xing,Chen, Zhi-Long
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- The effects of 5-aminolevulinic acid esters on protoporphyrin IX production in human adenocarcinoma cell lines
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Photodynamic diagnosis (PDD) and photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) is an interesting approach to detect and treat dysplasia and early cancers in the gastrointestinal tract. Because of low lipophi
- Brunner,Hausmann,Krieg,Endlicher,Schoelmerich,Knuechel,Messmann
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- Esters of 5-aminolevulinic acid as photosensitizing agents in photochemotherapy
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The invention provides compounds for use in photochemotherapy or diagnosis, said compounds being branched alkyl esters or substituted alkyl esters of 5-aminolevulinic acid, or derivatives or pharmaceutically acceptable salts thereof. In particular, the invention provides compounds of formula (I): R22N—CH2COCH2CH2CO—OR1 (wherein R1 represents an optionally substituted branched alkyl (e.g. C5-30 alkyl) group, or a substituted alkyl group; R2, each of which may be the same or different, represents a hydrogen atom or an optionally substituted alkyl group, preferably a group R1; wherein said substituents are selected from hydroxy, alkoxy, acyloxy, alkoxycarbonyloxy, amino, aryl, nitro, oxo, fluoro, —SR3, —NR32 and PR32 groups, and each alkyl group is optionally interrupted by one or more O—, —NR3—, —S— or —PR3— groups; and R3 represents a hydrogen atom or a C1-6 alkyl group) and salts thereof for use in diagnosis and photochemotherapy of disorders of abnormalities of external or internal surfaces of the body, and products and kits for performing the invention.
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