Determination of the glycosylation-pattern of the middle ear mucosa in guinea pigs.
In the present study the glycosylation pattern of the middle ear mucosa (MEM) of guinea pigs, an approved model for middle ear research, was characterized with the purpose to identify bioadhesive ligands which might prolong the contact time of drug delivery systems with the middle ear mucosa (MEM). To assess the utility of five fluorescein labeled plant lectins with different carbohydrate specificities as bioadhesive ligands, viable MEM specimens were incubated at 4°C and the lectin binding capacities were calculated from the MEM-associated relative fluorescence intensities. Among all lectins under investigation, fluorescein-labeled wheat germ agglutinin (F-WGA) emerged as the highest bioadhesive lectin. In general, the accessibility of carbohydrate moieties of the MEM followed the order: sialic acid and N-acetyl-d-glucosamine (WGA)>>mannose and galactosamine (Lensculinaris agglutinin)>N-acetyl-d-glucosamine (Solanumtuberosum agglutinin)>fucose (Ulexeuropaeus isoagglutinin I)>>terminal mannose α-(1,3)-mannose (Galanthusnivalis agglutinin). Competitive inhibition studies with the corresponding carbohydrate revealed that F-WGA-binding was inhibited up to 90% confirming specificity of the F-WGA-MEM interaction. The cilia of the MEM were identified as F-WGA binding sites by fluorescence imaging as well as a z-stack of overlays of transmission, F-WGA- and nuclei-stained images of the MEM. Additionally, co-localisation experiments revealed that F-WGA bound to acidic mucopolysaccharides of the MEM. All in all, lectin-mediated bioadhesion to the MEM is proposed as a new concept for drug delivery to prolong the residence time of the drug in the tympanic cavity especially for successful therapy for difficult-to-treat diseases such as otitis media.
Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Elisabeth
E
Engleder
Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Elisabeth
E
Demmerer
Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Xueyan
X
Wang
Department of Otorhinolaryngology, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria.
Clemens
C
Honeder
Department of Otorhinolaryngology, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria.
Chengjing
C
Zhu
Department of Pharmacology and Toxicology, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria.
Christian
C
Studenik
Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Michael
M
Wirth
Department of Otorhinolaryngology, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria.
Christoph
C
Arnoldner
Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria. Electronic address: franz.gabor@univie.ac.at.
Franz
F
Gabor
D000818:Animals; D004432:Ear, Middle / Q000187:drug effects / Q000378:metabolism*; D006031:Glycosylation; D006168:Guinea Pigs; D009092:Mucous Membrane / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D037121:Plant Lectins / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics*; D011485:Protein Binding / Q000502:physiology
D037121:Plant Lectins
Bioadhesive drug delivery; Guinea pigs; Lectins; Middle ear mucosa; Otitis media