HYDROPHOBICITY-DEPENDENT FLUORESCENCE PROPERTIES AND INTRACELLULAR FLUOROSPECTROSCOPIC BEHAVIOR OF PHOTOTOXIC DRUGS

Fluorospectroscopic behavior of chlorpromazine, mequitazine, afloqualone and piroxicam, which are known to induce skin photosensitivity, was examined in both homogeneous solutions and human buccal mucosal cells. Each drug showed large Stokes' shifts and their fluorescence intensities increased in hydrophobic solvents. These results indicated that the drugs tested can be used as hydrophobic fluorescence probes. Fluorescence microscopic observations of buccal mucosal cells treated with these drugs showed that all the drugs, especially chlorpromazine and mequitazine, were distributed in intracellular membranous regions.     

SYNTHESIS AND CHARACTERIZATION OF POLY(ASPARTIC ACID) AND ITS DERIVATIVES AS BIODEGRADABLE MATERIALS

ABSTRACT

Three types of modified poly(aspartic acid)s, such as poly(aspartic acid-co-aminocarboxylic acid) (4), alkylamine modified poly(aspartic acid) (5) and crosslinked poly(aspartic acid) (6), were synthesized and calcium-ion chelating ability, hygroscopicity and water absorption were evaluated. The calcium-ion chelating ability of 4 depended on the kind of aminocarboxylic acids and the content of aminocarboxylic acid in the copolymer. The highest value was 3 times higher than that of poly(acrylic acid) with a M_w of 14000. The highly modified PASP, e.g., 50 mol% lauryl amine modified poly(aspartic acid), showed the highest by grogroscopicity among homopoly(aspartic acid)s and modified poly(aspartic acid)s. The maximum swelling of poly(aspartic acid) hydrogel prepared by the γ-irradiation of homopoly(as-partic acid) was 3400 g-deionized water/g-dry hydrogel.     

Detection of highly oriented aggregation of L-glutamic acid-derived lipids in dilute organic solution

Aggregation structures in organic gels and xerogels formed from L-glutamic acid-derived lipids were investigated by scanning and transmission electron microscopies, X-ray analyses, and 1H NMR and IR spectroscopic methods. These analyses showed that the gels were produced through the formation of highly oriented aggregates based on a single layer and a remarkable development of their fibrous morphology. We also describe how the critical aggregation concentration can be observed at a concentration below the critical gel concentration by using a dye-complexation method with a cyanine dye, NK-77.