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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Poster Abstracts
59
22-POS
Board 11
Polystyrene Nanoparticles Alter the Structure and Stability of Model Cell Membranes
David R. Van Doren, Luke Cuculis.
Shelli L. Frey
,
Gettysburg College, Gettysburg, PA, USA.
Unique material properties of nanoparticles (NPs) contribute to a diversity of applications that
range from increasing transparency and protection of sunscreen to transporting drugs across cell
membranes without damaging the cell itself. Because the interactions of NPs with biological
membranes have not been fully characterized to correlate surface physical and chemical
characteristics with mode of action, model cell membranes exposed to NPs were monitored with
fluorescence microscopy. Giant unilamellar vesicles (GUVs) composed of 1:1:1
dipalmitoylphosphatidylcholine (DPPC)/1,2-dioleoyl-sn-glycero-3-phosphocholine
(DOPC)/cholesterol were prepared with 0.8% mol fluorescent TR-DHPE, exposed to NPs either
during the vesicle electroformation process or afterwards, and then imaged. The effects of
varying concentrations of 40, 60, or 100 nm functionalized polystyrene NPs were measured
through morphology changes and vesicle size distributions. Aminated polystyrene particles
reduced the size of stable GUVs with the magnitude of the effect scaling with NP concentration.
Additionally, the distribution of aminated nanoparticles within the membrane resulted in lipid
tubule formation that extended from the vesicle structure; the membrane bending may be
attributed to a NP crowding mechanism. Carboxylated particles produced less dramatic effects
compared to the control system. In both cases, high NP concentration completely prevented
GUV formation, indicating a saturation concentration effect. Understanding the features
impacting NP-membrane interactions may help elucidate health and environmental implications
of these associations and direct the design of better NP-based technology.