Ionic Dependence of Gelatin Hydrogel Architecture Explored Using Small and Very Small Angle Neutron Scattering Technique

Abstract

The hierarchical structure of gelatin hydrogels mimics a natural extracellular matrix and provides an optimized microenvironment for the growth of 3D structured tissue analogs. In the presence of metal ions, gelatin hydrogels exhibit various mechanical properties that are correlated with the molecular interactions and the hierarchical structure. The structure and structural response of gelatin hydrogels to variation of gelatin concentration, pH, or addition of metal ions are explored by small and very small angle neutron scattering over broad length scales. The measurements of the hydrogels reveal the existence of a two‐level structure of colloid‐like large clusters and a 3D cage‐like gel network. In the presence of Fe3+ ions the hydrogels show a highly dense and stiff network, while Ca2+ ions have an opposite effect. The results provide important structural insight for improvement of the design of gelatin based hydrogels and are therefore suitable for various applications.

Magnetic Nanoparticle Chains in Gelatin Ferrogels: Bioinspiration from Magnetotactic Bacteria

“…Thus, the gelatin gel does not only serve as an inert matrix limiting the diffusion process of the reacting ions and slowing down the growth process of magnetite NCs, but also provides active nucleation sites promoting the formation of magnetite NCs. [14] Recently performed molecular dynamic simulations show that a triple helical (Gly-Hyp-Pro) n peptide favors the binding of the Fe(OH) x motifs (forming in the early stage of magnetite crystallization) and thus induces the intergrowth of macromolecules and magnetite NCs already at the precursor stage, which is also recently proved by SANS. [13] Furthermore, the high-resolution (HR)-TEM images of isolated magnetite NCs clearly reveal the highly pronounced mosaic-like defected structure, although they demonstrate single-crystal like diffraction properties ( Figure S2, Supporting Information).…”

Effect of sticker clustering on the dynamics of associative networks

“…The value of q was chosen to be 0.04 nm À1 because it is low enough to be well within the Porod scattering regime. 25,27,35,36 As shown in Fig. 5, the clustering strength increases with decreasing average spacing between the stickers, l, for the random copolymers.…”

“…The main difference between the three polymers is captured by the first term, A/q n which defines the clustering strength from a large network structure and has been used as a method to evaluate the clustering strength of random polymer networks. 25,27,35,36 Note that while no quantitative relation can be inferred from this factor, a high clustering strength is associated with networks while low clustering strength corresponds to dissolved chains. 25,27,35,36 The clustering strength is significantly higher for PDHMc8 compared to PDHM5 and PDHM10 (Fig.…”

“…25,27,35,36 Note that while no quantitative relation can be inferred from this factor, a high clustering strength is associated with networks while low clustering strength corresponds to dissolved chains. 25,27,35,36 The clustering strength is significantly higher for PDHMc8 compared to PDHM5 and PDHM10 (Fig. 5).…”

Gelatin Hydrogel-Based Organic Electrochemical Transistors and Their Integrated Logic Circuits

“…Compared to the liquid-like electrolyte, for example, NaCl and KCl, with active Ag and AgCl gate electrodes in the conventional OECT, this gelatin hydrogel contacted on the PEDOT:PSS surface has limited mobile ions. − We have modified the gelatin materials by applying additives such as acid and base to have enough mobile cations and anions, so that their mobile charges are able to easily penetrate into the PEDOT:PSS interface. By modulating the pH condition of gelatin hydrogels, the concentrations of hydrogen ions and hydroxide ions at the interface vary with the conductivity of PEDOT:PSS.…”