Hydrogels

Due to the shortage of organ donors, printing methods of tissues or organs have become widespread. In order to fulfill this need, the cell or biomolecule is embedded in a hydrogel and these mixtures are printed using a computer controlled rapid prototyping system to produce a printed organ (9). Bioprinting is a promising high-throughput technique for producing tissue engineered artificial tissues and organs. Gels with or without cell / biological factors are printed layer by layer in place with the ultimate goal of immobilizing damaged or diseased tissue (Fig. 1) (8, 9).

We have proposed the use of poly (dimethylacrylamide) hydrogel as a pore forming matrix for the synthesis of mesoporous metal oxides. 2-4 hydrogels are prepared by photocrosslinking of the respective polymer. The hydrogel is swollen in a metal salt solution and subsequently calcined to produce a metal oxide with homogeneous mesopores. 4 nanometers This method is between "soft" and "hard template". Like hydrogels, hydrogels form a continuous network that occupies inorganic precursor materials without the risk of phase separation. At the same time, the swollen hydrogel is a very flexible phase and the (crosslinked) polymer strands are somewhat loosely aligned and movable like a soft matrix. In addition, the hydrogel can be fixed to the surface of the substrate by covalent bonding, which contributes to the preparation of a film having a thickness in the μm to sub μm range.

In this paper, we summarized the principle of hydrogel network design, combination of molecular switches and the principle of hydrogel microstructure and enabled space-oriented operation of hydrogels by shape memory effect (SME) without large volume. change. SME involves elastic deformation (programming) of the sample temporarily fixed by reversible covalent bonding or physical crosslinking, resulting in a temporary shape. When these molecular switches are affected by the application of appropriate stimuli, the material can be inverted to its original shape. Hydrophobic shape memory polymers (SMPs) with complex functions including multiple or reversible shape transformations can give inspiration to the molecular structure of shape memory hydrogels (SMH), but are called softness of hydrophilicity It is a material that can not be reproduced in the same world. A triple-shaped hydrogel can be achieved by introducing such a side chain of the second type.

Shape memory hydrogels: evolution of structural principles to achieve shape transformation of hydrophilic polymer networks