title: Comparative evaluation of cytotoxicity of a glucosamine-TBA conjugate and a chitosan-TBA conjugate.
abstract: D-glucosamine and chitosan were modified by the immobilization of thiol groups utilizing 2-iminothiolane. The toxicity profile of the resulting D-glucosamine-TBA (4-thiobutylamidine) conjugate, of chitosan-TBA conjugate and of the corresponding unmodified controls was evaluated in vitro. On the one hand, the cell membrane damaging effect of 0.025% solutions of the test compounds was investigated via red blood cell lysis test. On the other hand, the cytotoxity of 0.025, 0.25 and 0.5% solutions of the test compounds was evaluated on L-929 mouse fibroblast cells utilizing two different bioassays: the MTT assay (3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide), which assess the mitochondrial metabolic activity of the cells, and the BrdU-based enzyme-linked immunosorbent assay, which measures the incorporation in the DNA of 5-bromo-2'-deoxyuridine and consequently the cell proliferation. Results of the red blood cell lysis test showed that both thiolated compounds displayed a lower membrane damaging effect causing a significantly lower haemoglobine release than the unmodified compounds. Data obtained by the MTT assay and the BrdU assay revealed a concentration dependent relative cytotoxicity for all tested compounds. The covalent linkage of the TBA-substructure to D-glucosamine did not cause a significant increase in cytotoxicity, whereas at higher concentrations a slightly enhanced cytotoxic effect was caused by the derivatisation of chitosan. In conclusion, the -TBA derivatives show a comparable toxicity profile to the corresponding unmodified compounds, which should not compromise their future use as save pharmaceutical excipients.
authors.affiliation: Center of Pharmacy, Institute of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstr. 14, 1090, Austria.
authors.forename: Davide
authors.initials: D
authors.lastname: Guggi
authors.forename: Nina
authors.initials: N
authors.lastname: Langoth
authors.forename: Martin H
authors.initials: MH
authors.lastname: Hoffer
authors.forename: Michael
authors.initials: M
authors.lastname: Wirth
authors.forename: Andreas
authors.initials: A
authors.lastname: Bernkop-Schnürch
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity*; D004910:Erythrocyte Membrane / Q000187:drug effects; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity*; D006461:Hemolysis; D007096:Imidoesters / Q000737:chemistry; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D011108:Polymers / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar
chemical_list: C493041:D-glucosamine-(4-thiobutylamidine); D007096:Imidoesters; D011108:Polymers; C493042:chitosan-4-thiobutylamidine; D002686:Chitin; C005905:methyl 4-mercaptobutyrimidate; D005944:Glucosamine