The Influence of Differently Shaped Gold Nanoparticles Functionalized with NIPAM-Based Hydrogels on the Release of Cytochrome C

Sulalit Bandyopadhyay; Anuvansh Sharma; Wilhelm Robert Glomm

doi:10.3390/gels3040042

The Influence of Differently Shaped Gold Nanoparticles Functionalized with NIPAM-Based Hydrogels on the Release of Cytochrome C

Gels. 2017 Nov 8;3(4):42. doi: 10.3390/gels3040042.

Authors

Sulalit Bandyopadhyay¹, Anuvansh Sharma², Wilhelm Robert Glomm^{3

4}

Affiliations

¹ Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Science and technology (NTNU), N-7491 Trondheim, Norway. sulalit.bandyopadhyay@ntnu.no.
² Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Science and technology (NTNU), N-7491 Trondheim, Norway. anuvansh.sharma@ntnu.no.
³ Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Science and technology (NTNU), N-7491 Trondheim, Norway. Wilhelm.glomm@sintef.no.
⁴ Polymer Particle and Surface Chemistry Research Group, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway. Wilhelm.glomm@sintef.no.

Abstract

Here, we report the synthesis and functionalization of five different shapes of Au nanoparticles (NPs), namely nanorods, tetrahexahedral, bipyramids, nanomakura, and spheres with PEG and poly (N-isopropylacrylamide)-acrylic acid (pNIPAm-AAc) hydrogels. The anisotropic NPs are synthesized using seed-mediated growth in the presence of silver. The NPs have been characterized using Dynamic Light Scattering (DLS), zeta potential measurements, UV-Visible spectrophotometry (UV-Vis), and Scanning Transmission Electron Microscopy (S(T)EM). Cyt C was loaded into the PEG-hydrogel-coated AuNPs using a modified breathing-in method. Loading efficiencies (up to 80%), dependent on particle geometry, concentration, and hydrogel content, were obtained. Release experiments conducted at high temperature (40 °C) and acidic pH (3) showed higher release for larger sizes of PEG-hydrogel-coated AuNPs, with temporal transition from spherical to thin film release geometry. AuNP shape, size, number density, and hydrogel content are found to influence the loading as well as release kinetics of Cyt C from these systems.

Keywords: NIPAm; PEG; anisotropy; cytochrome C; gold; nanostructures.