Publications by authors named "Jessie L Webber"

An antimicrobial peptide, nisin Z, was embedded within polyelectrolyte multilayers (PEMs) composed of natural polysaccharides in order to explore the potential of forming a multilayer with antimicrobial properties. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR), the formation of carrageenan/chitosan multilayers and the inclusion of nisin Z in two different configurations was investigated. Approximately 0.

View Article and Find Full Text PDF

Hypothesis: Odd-even effects in polysaccharide polyelectrolyte multilayers influence their hydration content and the chemical environment of the water within them.

Experiments: Polysaccharide polyelectrolyte multilayers (PEMs) composed of pharmaceutical grade fucoidan and chitosan were studied under confinement using synchrotron FTIR microspectroscopy at increasing pressure, in order to isolate and measure infrared spectra of water within the PEM, without interference from bulk water. Complementary studies of the PEMs were carried out using lab-based in situ attenuated total reflectance Fourier transform spectroscopy (ATR FTIR) and quartz crystal microbalance with dissipation monitoring (QCM-D), as well as zeta potential measurements, to determine the quantity of adsorbed polymer, hydration content, film thickness, viscoelastic properties and surface charge during layer-by-layer deposition.

View Article and Find Full Text PDF

The interfacial behavior of surfactants present in a natural extract from Quillaja saponaria Molina bark at the air-solution interface is studied by measurements of interfacial tension, interfacial elasticity, and interfacial reflectance FTIR spectroscopy. The active molecule, saponin, is observed directly at the air-solution interface (via reflectance FTIR spectroscopy) above and below the pKa of the molecule, and spectra confirm the altered charge of the interfacial layer at the two solution conditions. For all concentrations of saponin studied, and at pH values below and above pKa (i.

View Article and Find Full Text PDF

Soft polymer films, such as polyelectrolyte multilayers (PEMs), are useful coatings in materials science. The properties of PEMs often rely on the degree of hydration, and therefore the study of these films in a hydrated state is critical to allow links to be drawn between their characteristics and performance in a particular application. In this work, we detail the development of a novel soft contact cell for studying hydrated PEMs (poly(sodium 4-styrenesulfonate)/poly(allylamine hydrochloride)) using FTIR microspectroscopy.

View Article and Find Full Text PDF

Hypothesis: Solid-state lipid formulations, whereby liquid lipids are encapsulated in inorganic particle matrices, have attracted significant interest for drug/nutrient delivery in recent years. We hypothesized that the surface chemistry of the inorganic material used to encapsulate lipids impacts the lipase-mediated digestion and partitioning of lipolytic species between the solubilized aqueous and insoluble pellet phases.

Experiments: Medium chain triglycerides were spray dried with silica nanoparticles, montmorillonite or laponite platelets to form inorganic-lipid hybrid particles.

View Article and Find Full Text PDF

A polyelectrolyte multilayer (PEM) system based on biopolymers has been constructed and studied in its formation and enzymatic breakdown. The multilayer is composed of fucoidan (a proven antimicrobial/anti-inflammatory seaweed-based polysaccharide) and poly-l-arginine (a polypeptide that can be readily degraded with trypsin to yield arginine, a known NO donor), thus making the multilayer a potential dual action surface treatment for wound dressings. Studies on the formation of the multilayer revealed that the film built-up in the expected stepwise manner with consistent reversal of the zeta potential upon the adsorption of each subsequent polyion.

View Article and Find Full Text PDF

Two different fucoidan polymers (unfractionated Fucus vesiculosus fucoidan, and fractionated low molecular weight Fucus vesiculosus fucoidan) have been used to create substrates for protein adsorption studies. Polyelectrolyte multilayers were formed using the fucoidans (polyanions) with chitosan as the corresponding polycation. Multilayer formation was studied using zeta potential measurements, quartz crystal microbalance with dissipation monitoring (QCM-D) and attenuated total reflectance (ATR) FTIR spectroscopy.

View Article and Find Full Text PDF

We studied the interfacial mechanical properties of polyelectrolyte multilayer assemblies of poly(diallylamine hydrochloride) (PAH) and poly(4-styrenesulfonate)sodium salt (PSS) at the air-water interface using axisymmetric drop shape analysis (ADSA) during hydrostatic inflation as a function of aqueous salt concentration and two different polyanion molecular weights (M ∼ 13 and 70 kDa). Surface elastic moduli (G) ranged from 50 to 300 mN m. Using the measured film thickness, the bulk moduli (G) ranged from 10 to 90 MPa consistent with elastomeric solids.

View Article and Find Full Text PDF