(715h) Polyacrylamide Hydrogels Prepared Using Templates: Synthesis, Characterization and Efficiency of Separation of Macromolecules

Nanoporous polymer hydrogels offer a desirable combination of mechanical, optical, and transport characteristics that have placed them at the core of a variety of biomedical technologies including engineered tissue scaffolds, substrates for controlled release of pharmaceutical compounds, and sieving matrices for electrophoretic separation of DNA and proteins. All these applications are closely related to the nanoporous morphology of the matrix, especially the mean pore size and its distribution.

Crosslinked polyacrylamide is a widely used gel matrix for protein and DNA electrophoresis because it offers a number of attractive properties including excellent separation resolution, optical/UV transparency, and electro-neutrality. In order to rationally engineer gels with properties that are optimally suitable for any of these applications, it is essential to understand the nature of the gel pore structure and parameters through which it can be manipulated.

In this work we study the efficiency of separation of macromolecules through a porous structure of polyacrylamide hydrogel obtained by two methods of polymerization: 1) through a more common protocol to develop a separation in a capillary gel electrophoresis system and 2) through photo-initiated polymerization. The porous structure was formed using nanotemplates based in Sodium Dodecyl Sulfate. Different concentrations of SDS were studied in order to assess the influence of the size and distribution of the pores on the separation process of macromolecules. The porous structure was characterized using novel techniques in which the hydrogel samples are prepared at room temperature for direct visualization of nanoporous morphology using transmission electron microscopy (TEM). Additionally, other techniques to characterize the porous structure were explored such as: Thermoporometry, Dynamic Mechanical Analysis and Computed Tomography Imaging Spectrometer. The results regarding the efficiency of separation of macromolecules and the characterization of the porous structure are compared and discussed for each type of polymerization. Directions for future research are also included.