Poster Session 4, 2:15 PM - 3:00 PM: Campus Center Auditorium [A48]

Biomembrane Interactions with Model Microplastics

Presenter: Mya Rachel Grossman

Faculty Sponsor: Maria Santore

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

ABSTRACT

Micron-scale particles, including microplastics, increasingly interact with human cells. However,

their interactions with cell membranes remain poorly understood. My research investigates how

such particles adhere to model cell membranes using Giant Unilamellar Vesicles (GUVs), which

are microscopic lipid vesicles that mimic the surface of human cells.

GUVs are generated through electroformation. The initial stages of my project focused on

optimizing electroformation conditions to reproducibly create large batches of vesicles.

Parameters including applied voltage and frequency from a function generator, osmolarity of

sugar solutions, temperature, and electroforming duration were thoroughly examined and

refined, as each of these factors impacts the yield and quality of produced vesicles. The

electroformed GUVs were composed of two lipids with distinct charge properties: DOPC, a

neutral and zwitterionic lipid, and DOTAP, a cationic lipid which is used to impact membrane

surface charge.

To enable adhesion assays, I developed a purification protocol to remove particulate debris and

membrane fragments that interfere with membrane-particle interactions. A sedimentation and

re-sedimentation protocol was established by matching osmolarity conditions between sugars

used in the electroformation chamber and in the sedimentation assay, as well as determining a

time frame at which vesicles were settled at the bottom of a suspension tube and still viable. This

approach has demonstrated the production of purified vesicles suitable for adhesion studies.

By establishing a basis for vesicle formation and purification, this research provides a controlled

system for studying membrane–particle interactions and contributes to understanding how

synthetic particles may interact with human cell membranes.

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