Dependence of the swelling behavior of a pH-responsive PEG-modified nanogel on the cross-link density

作者：Tamura Goshu; Shinohara Yuya^*; Tamura Atsushi; Sanada Yusuke; Oishi Motoi; Akiba Isamu; Nagasaki Yukio; Sakurai Kazuo; Amemiya Yoshiyuki

来源：Polymer Journal, 2012, 44(3): 240-244.

DOI：10.1038/pj.2011.123

• drug delivery system
• PEGylated nanogel
• pH-responsive swelling
• small-angle X-ray scattering

We report pH-responsive structural changes in PEG-modified (PEGylated) nanogels, as determined by using small-angle X-ray scattering and dynamic light scattering. The size of the nanogels discontinuously increased at a lower pH than the pK(a) of the nanogels. This size increase was attributed to the swelling of the core part of the nanogel upon a change in pH. The swelling behavior was dependent on the cross-link density of the core. When the cross-link density was low, the core swelled greatly with preserving the polydispersity in size and maintained a constant shape; however, when the cross-link density was high, the core swelled minimally, and only the polydispersity increased. This difference in swelling behavior is discussed in terms of the inhomogeneous structural distribution of cross-links in the core. Polymer Journal (2012) 44, 240-244; doi:10.1038/pj.2011.123; published online 23 November 2011

• 出版日期2012-3