The understanding of how nanoparticles
(NPs) specifically bind to receptors in
cell membranes is still lacking. In particular,
a focus on decorating NPs with
specifically binding ligand for target receptors
have largely ignored the influence
of nonspecific colloidal interactions
on targeting affinity. Thus, model systems
were established in order to set a basis
for interpretation of the effect on the
avidity of NPs. Silica NPs were coated
with lipid bilayers by liposome fusion, using
different composition liposomes that
would modulate the interaction potential
of the particles. A controlled density of
biotin functional groups in the lipid membrane
served as a model for specific interactions
with avidin proteins. The quality
of the coating was estimated by dynamic
light scattering and zeta potential.
An optimal coating procedure was developed.
In addition, supported lipid bilayers
and poly(ethylene glycol) surface
coatings were self-assembled on silica sensor
surfaces with different coverages of
avidin proteins to mimic the cell membrane
and used to investigate the specific
and non-specific interactions with coated
silica NPs via Quartz Crystal Microbalance
with Dissipation monitoring.