Colloids

Vaporizable Endoskeletal Drops

Our group recently discovered a new solid-in-liquid (endoskeletal) drop composition. The endoskeletal drops are suspended in water and have exciting biomedical applications. On one hand, a fluorocarbon solid in a fluorocarbon liquid stabilizes the liquid phase against vaporizaiton and creates very interseting structures (see image below). On the other hand, hydrocarbon solid in a fluorocarbon liquid allows vaporization near the melting point of the hydrocarbon solid - a new vaporization mechanism that we call "interfacial melting".

Read about the discovery here:

gazendra figure

Lipid Monolayer Intermolecular and Surface Forces

In collaboration with Todd Murray, our group is using novel laser acoustics methods to measure the viscoelastic properties of lipid microbubble shells. Read more here: , , ,

photoacoustics

We are also investigating models to link the chemistry to the interfacial transport properties via the intermolecular and surface forces. Read more here: ,

lipid molecules have a head region made from choline, phosphate, and glycerol. The tail region has an ester and n-methylene groups per acyl chain. Lipid molecules are surrounded by HCP neighboring tail groups.

Lung Surfactant Microbubbles (Synthetic Alveoli)

Another major goal of our lab is to examine the mechanical and gas transport properties of bio-mimetic lung surfactant films for the engineering of synthetic alveoli for oxygen delivery.

Read more here: , , ,

survanta surfactant turns to a nanodrop shape after 375.6 seconds at 0.5 kilopascals. At 2.3 kilopascals, it takes 90.1 seconds to turn into a nanobubble. For a DPPC at 0.5 kilopascals, it takes 331 seconds to turn into a nanobubble. At 2.3 kilopascals, it takes a DPPC surfactant 85.9 seconds.

Multifunctional Colloids

Our group is contantly synthesizing and characterizing novel colloidal constructs with multiple therapeutic and diagnostic functions. Examples include Gd-labeled microbubbles for MRI-guided focused ultrasound surgery, lung surfactant microbubbles for enhanced lipophilic drug payload, and polyplex-loaded microbubbles for ultrasound-targeted gene therapy. The example below shows recent work on gold nanoparticle-coated nanodrops for photoacoustic imaging and photothermal therapy. Read more here:

a gold nanoparticle coated nanodrop, which has a core that turns liquid as the temperature decreases and the pressure increases from 100 to 150 kilopascals