Erosion of multilayered films fabricated from degradable polyamines: Characterization and evidence in support of a mechanism that involves polymer hydrolysis

Authors

  • Jingtao Zhang,

    1. Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
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  • Nathaniel J. Fredin,

    1. Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
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  • David M. Lynn

    Corresponding author
    1. Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
    • Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, Wisconsin 53706
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Abstract

Multilayered polyelectrolyte assemblies fabricated using hydrolytically degradable polyamines (13) erode gradually when incubated in physiologically relevant media. This investigation sought to characterize physically and chemically the erosion of films fabricated from these polymers and sodium poly(styrene sulfonate) (SPS) and to investigate specifically the potential role of polymer hydrolysis in governing film erosion. The characterization of erosion using reflective infrared spectroscopy revealed changes in the carbonyl region of the spectrum that were consistent with the generation of polymer hydrolysis products. To evaluate the role of the esters in these materials more directly, we also synthesized a structural analogue of polymer 2 containing amide functionality rather than ester functionality. Assemblies fabricated from this amide-containing polymer did not erode significantly or release SPS into solution when incubated in phosphate-buffered saline (PBS). Finally, we characterized the erosion of assemblies fabricated from polymer 1 in PBS buffer prepared with D2O rather than H2O. These assemblies eroded significantly more slowly in deuterated media than in buffer prepared with H2O. These results, when combined, provide support for the view that polymer hydrolysis plays an important role in governing the erosion of assemblies fabricated from these degradable polymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5161–5173, 2006

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