Nanostructurered delivery system, comprising at least one polymer, and/or at least one lipid and at least one polymethine dye for use in the treatment of diseases of the liver and/or the kidneys, wherein the at least polymethine dye, as a targeting unit, causes the transport of the nanostructured delivery system into the target tissue, and wherein the at least one polymethine dye is a symmetrical or asymmetrical polymethine of the general structure I, II, III or IV: wherein a. n stands for the numerical values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, b. R 1 -R 17 may be the same or different and maybe hydrogen, one or more alkyl, tert-alkyl, cycloalkyl or aryl-, carboxyaryl-, dicarboxyaryl-, heteroaryl- or heterocycloaliphatic radicals, alkyloxy-, alkylmercapto, heteroaryloxy-, heteroarylmercapto-, hydroxyl-, nitro- or cyano- group, an alkyl-substituted or cyclic amine function and/or two ortho-position radicals, e.g., R 3 and R 4, R 13 and R 14 and/or R 1 and R 2 and R 11 and R 12 and/or R 7 and R 9 together may form an additional aromatic, heteroaromatic, aliphatic or heteroaliphatic ring, c. at least one of the R 1 -R 17 substituents has a solubilizing and/or ionizable or ionized substituent such as SO 3 -, (- SO 3 H), PO 3 2-, COOH, OH or NR 3 +, cyclodextrins or sugar, which determines the hydrophilic properties of these polymethine dyes, wherein this substituent may be bound to the polymethine dye also by a spacer group, and d. at least one of the R 1 -R 17 substituents has a reactive group (linker) such as isocyanates, isothiocyanates, hydrazines, amines, mono- and dichloro- or mono- and dibromotriazines, aziridines, epoxides, sulfonyl halides, acid halides, carboxylic anhydrides, N-hydroxysuccinimide esters, imido esters, carboxylic acids, glyoxal, aldehyde, maleimide or iodacetamide and phosphoramidite derivatives or azides, alkynes or olefins, wherein this substituent may be bound to the polymethine dye also by a spacer group, e. the aromatic, heteroaromatic, aliphatic or heteroaliphatic spacer group consists of structural elements such as [(CH 2) a) - Y- (CH 2) b] c or [(C 6 H 4) a) - Y- (C 6 H 4) b], where Y may be the same or different and comprises CR 2 -, O-, S-, SO 2, SO 2 NH-, NR-, COO- or CONR functions, wherein it is bound to one of the R 1 -R 17 substituents, and a and b may be the same or different and have numerical values of 0-18 and numerical values for c of 0-18, f. the R 8 and R 9 substituents with corresponding n=2, 3, 4 or 5, may also be present 2x, 3x, 4x or 5x, and wherein these may be the same or different, and wherein the nanostructured delivery system comprises at least pharmaceutically active ingredient. a. n stands for the numerical values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, b. R 1 -R 17 may be the same or different and maybe hydrogen, one or more alkyl, tert-alkyl, cycloalkyl or aryl-, carboxyaryl-, dicarboxyaryl-, heteroaryl- or heterocycloaliphatic radicals, alkyloxy-, alkylmercapto, heteroaryloxy-, heteroarylmercapto-, hydroxyl-, nitro- or cyano- group, an alkyl-substituted or cyclic amine function and/or two ortho-position radicals, e.g., R 3 and R 4, R 13 and R 14 and/or R 1 and R 2 and R 11 and R 12 and/or R 7 and R 9 together may form an additional aromatic, heteroaromatic, aliphatic or heteroaliphatic ring, c. at least one of the R 1 -R 17 substituents has a solubilizing and/or ionizable or ionized substituent such as SO 3 -, (- SO 3 H), PO 3 2-, COOH, OH or NR 3 +, cyclodextrins or sugar, which determines the hydrophilic properties of these polymethine dyes, wherein this substituent may be bound to the polymethine dye also by a spacer group, and d. at least one of the R 1 -R 17 substituents has a reactive group (linker) such as isocyanates, isothiocyanates, hydrazines, amines, mono- and dichloro- or mono- and dibromotriazines, aziridines, epoxides, sulfonyl halides, acid halides, carboxylic anhydrides, N-hydroxysuccinimide esters, imido esters, carboxylic acids, glyoxal, aldehyde, maleimide or iodacetamide and phosphoramidite derivatives or azides, alkynes or olefins, wherein this substituent may be bound to the polymethine dye also by a spacer group, e. the aromatic, heteroaromatic, aliphatic or heteroaliphatic spacer group consists of structural elements such as [(CH 2) a) - Y- (CH 2) b] c or [(C 6 H 4) a) - Y- (C 6 H 4) b], where Y may be the same or different and comprises CR 2 -, O-, S-, SO 2, SO 2 NH-, NR-, COO- or CONR functions, wherein it is bound to one of the R 1 -R 17 substituents, and a and b may be the same or different and have numerical values of 0-18 and numerical values for c of 0-18, f. the R 8 and R 9 substituents with corresponding n=2, 3, 4 or 5, may also be present 2x, 3x, 4x or 5x, and wherein these may be the same or different, and wherein