Lipids Commons^™

Colloidal Nanomaterial Surface Chemistry And Characterization Studied By Linear And Nonlinear Spectroscopy, Asela Sampath Dikkumbura

LSU Doctoral Dissertations

Recent studies have demonstrated the use of nanomaterials such as metallic nanoparticles, liposomes, and polymer microparticles for biomedical applications, encompassing the field of nanomedicine. For developing novel core-shell metallic nanoparticles with controlled surface morphology, the in situ growth dynamics of colloidal silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) in water are monitored in a stepwise synthesis approach using time-dependent second harmonic generation (SHG) and extinction spectroscopy. Transmission electron microscopy images show that the CS NP surface morphology becomes more smooth and uniform as the reaction proceeds, corresponding to lower, stable SHG signals and narrower plasmonic spectra that are compared to finite-difference …

Cardiolipin Prevents Membrane Translocation And Permeabilization By Daptomycin, Tianhua Zhang, Jawad K. Muraih, Nasim Tishbi, Jennifer Herskowitz, Rachel L. Victor, Jared Silverman, Stephanie Uwumarenogie, Scott D. Taylor, Michael Palmer, Evan Mintzer

Lander College of Arts and Sciences Publications and Research

Daptomycin is an acidic lipopeptide antibiotic that, in the presence of calcium, forms oligomeric pores on membranes containing phosphatidylglycerol. It is clinically used against various Gram-positive bacteria such as Staphylococcus aureus and Enterococcusspecies. Genetic studies have indicated that an increased content of cardiolipin in the bacterial membrane may contribute to bacterial resistance against the drug. Here, we used a liposome model to demonstrate that cardiolipin directly inhibits membrane permeabilization by daptomycin. When cardiolipin is added at molar fractions of 10 or 20% to membranes containing phosphatidylglycerol, daptomycin no longer forms pores or translocates to the inner membrane leaflet. Under …

Quantification Of Factors Governing Drug Release Kinetics From Nanoparticles: A Combined Experimental And Mechanistic Modeling Approach, Kyle Daniel Fugit

Theses and Dissertations--Pharmacy

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies.

A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release …