Medicine and Health Sciences Commons^™

Amphiphilic Tobramycin Analogues As Antibacterial And Antifungal Agents, Sanjib K. Shrestha, Marina Y. Fosso, Keith D. Green, Sylvie Garneau-Tsodikova

Pharmaceutical Sciences Faculty Publications

In this study, we investigated the in vitro antifungal activities, cytotoxicities, and membrane-disruptive actions of amphiphilic tobramycin (TOB) analogues. The antifungal activities were established by determination of MIC values and in time-kill studies. Cytotoxicity was evaluated in mammalian cell lines. The fungal membrane-disruptive action of these analogues was studied by using the membrane-impermeable dye propidium iodide. TOB analogues bearing a linear alkyl chain at their 6″-position in a thioether linkage exhibited chain length-dependent antifungal activities. Analogues with C₁₂ and C₁₄ chains showed promising antifungal activities against tested fungal strains, with MIC values ranging from 1.95 to 62.5 mg/liter …

Influence Of Linker Length And Composition On Enzymatic Activity And Ribosomal Binding Of Neomycin Dimers, Derrick Watkins, Sunil Kumar, Keith D. Green, Dev P. Arya, Sylvie Garneau-Tsodikova

Pharmaceutical Sciences Faculty Publications

The human and bacterial A site rRNA binding as well as the aminoglycoside-modifying enzyme (AME) activity against a series of neomycin B (NEO) dimers is presented. The data indicate that by simple modifications of linker length and composition, substantial differences in rRNA selectivity and AME activity can be obtained. We tested five different AMEs with dimeric NEO dimers that were tethered via triazole, urea, and thiourea linkages. We show that triazole-linked dimers were the worst substrates for most AMEs, with those containing the longer linkers showing the largest decrease in activity. Thiourea-linked dimers that showed a decrease in activity by …

Alternating Magnetic Field-Induced Hyperthermia Increases Iron Oxide Nanoparticle Cell Association/Uptake And Flux In Blood-Brain Barrier Models, Mo Dan, Younsoo Bae, Thomas A. Pittman, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

PURPOSE: Superparamagnetic iron oxide nanoparticles (IONPs) are being investigated for brain cancer therapy because alternating magnetic field (AMF) activates them to produce hyperthermia. For central nervous system applications, brain entry of diagnostic and therapeutic agents is usually essential. We hypothesized that AMF-induced hyperthermia significantly increases IONP blood-brain barrier (BBB) association/uptake and flux.

METHODS: Cross-linked nanoassemblies loaded with IONPs (CNA-IONPs) and conventional citrate-coated IONPs (citrate-IONPs) were synthesized and characterized in house. CNA-IONP and citrate-IONP BBB cell association/uptake and flux were studied using two BBB Transwell^® models (bEnd.3 and MDCKII cells) after conventional and AMF-induced hyperthermia exposure.

RESULTS: …

Fret Detection Of Lymphocyte Function-Associated Antigen-1 Conformational Extension, Alexandre Chigaev, Yelena Smagley, Mark K. Haynes, Oleg Ursu, Cristian G. Bologa, Liliana Halip, Tudor Oprea, Anna Waller, Mark B. Carter, Yinan Zhang, Wei Wang, Tione Buranda, Larry A. Sklar

Pharmaceutical Sciences Faculty Publications

Lymphocyte function-associated antigen 1 (LFA-1, CD11a/CD18, αLβ2-integrin) and its ligands are essential for adhesion between T-cells and antigen-presenting cells, formation of the immunological synapse, and other immune cell interactions. LFA-1 function is regulated through conformational changes that include the modulation of ligand binding affinity and molecular extension. However, the relationship between molecular conformation and function is unclear. Here fluorescence resonance energy transfer (FRET) with new LFA-1-specific fluorescent probes showed that triggering of the pathway used for T-cell activation induced rapid unquenching of the FRET signal consistent with extension of the molecule. Analysis of the FRET quenching at rest revealed an …