We report the design and characterization of thin polymer-based
coatings that promote the contact transfer of DNA to soft surfaces
under mild and physiologically relevant conditions. Past studies reveal
polymer multilayers fabricated using linear poly(ethylene imine) (LPEI),
poly(acrylic acid) (PAA), and plasmid DNA promote contact transfer
of DNA to vascular tissue. Here, we demonstrate that changes in the
structure of the polyamine building blocks of these materials can
have substantial impacts on rates and extents of contact transfer.
We used two hydrogel-based substrate models that permit identification
and manipulation of parameters that influence contact transfer. We
used a planar gel model to characterize films having the structure
(cationic polymer/PAA/cationic polymer/plasmid DNA)x fabricated using either LPEI or one of three poly(β-amino
ester)s as polyamine building blocks. The structure of the polyamine
influenced subsequent contact transfer of DNA significantly; in general,
films fabricated using more hydrophilic polymers promoted transfer
more effectively. This planar model also permitted characterization
of the stabilities of films transferred onto secondary surfaces, revealing
rates of DNA release to be slower than rates of release prior to transfer.
We also used a three-dimensional hole-based hydrogel model to evaluate
contact transfer of DNA from the surfaces of inflatable catheter balloons
used in vascular interventions and selected a rapid-transfer coating
for proof-of-concept studies to characterize balloon-mediated contact
transfer of DNA to peripheral arterial tissue in swine. Our results
reveal robust and largely circumferential transfer of DNA to the luminal
walls of peripheral arteries using inflation times as short as 15
to 30 s. The materials and approaches reported here provide new and
useful tools for promoting rapid, substrate-mediated contact transfer
of plasmid DNA to soft surfaces in vitro and in vivo that could prove
useful in a range of fundamental and applied contexts