Nano-Imprinted Thin Films of Reactive, Azlactone-Containing Polymers: Combining Methods for the Topographic Patterning of Cell Substrates with Opportunities for Facile Post-Fabrication Chemical Functionalization

Authors

Nathaniel J. Fredin, University of Wisconsin-Madison
Ryan M. Flessner, University of Wisconsin-Madison
Christopher M. Jewell, University of Wisconsin-Madison
Shane L. Bechler, University of Wisconsin-Madison
Maren E. Buck, University of Wisconsin-MadisonFollow
David M. Lynn, University of Wisconsin-Madison

Document Type

Article

Publication Date

9-1-2010

Publication Title

Microscopy Research and Technique

Abstract

Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) were used to characterize changes in nanoscale structure that occur when ultrathin polyelectrolyte multilayers (PEMs) are incubated in aqueous media. The PEMs investigated here were fabricated by the deposition of alternating layers of plasmid DNA and a hydrolytically degradable polyamine onto a precursor film composed of alternating layers of linear poly(ethylene imine) (LPEI) and sodium poly(styrene sulfonate) (SPS). Past studies of these materials in the context of gene delivery revealed transformations from a morphology that is smooth and uniform to one characterized by the formation of nanometer-scale particulate structures. We demonstrate that in-plane registration of LSCM and AFM images acquired from the same locations of films fabricated using fluorescently labeled polyelectrolytes allows the spatial distribution of individual polyelectrolyte species to be determined relative to the locations of topographic features that form during this transformation. Our results suggest that this physical transformation leads to a morphology consisting of a relatively less disturbed portion of film composed of polyamine and DNA juxtaposed over an array of particulate structures composed predominantly of LPEI and SPS. Characterization by scanning electron microscopy and energy-dispersive X-ray microanalysis provides additional support for this interpretation. The combination of these different microscopy techniques provides insight into the structures and dynamics of these multicomponent thin films that cannot be achieved using any one method alone, and could prove useful for the further development of these assemblies as platforms for the surface-mediated delivery of DNA.

Keywords

DNA delivery, Nanostructure, Polymers, layer-by-layer, Thin films

Volume

73

Issue

9

First Page

834

Last Page

844

DOI

10.1002/jemt.20830

ISSN

1059910X

Comments

Peer reviewed accepted manuscript.

Recommended Citation

Fredin, Nathaniel J.; Flessner, Ryan M.; Jewell, Christopher M.; Bechler, Shane L.; Buck, Maren E.; and Lynn, David M., "Nano-Imprinted Thin Films of Reactive, Azlactone-Containing Polymers: Combining Methods for the Topographic Patterning of Cell Substrates with Opportunities for Facile Post-Fabrication Chemical Functionalization" (2010). Chemistry: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/chm_facpubs/31