Nonionic hydrogels

Taguchi, T., Shiraogawa, M., Kishida, A. and Akashi, M. (1999) A study on hydroxyapatite formation on/in the hydroxyl groups-bearing nonionic hydrogels. Journal of Biomaterials Science-Polymer Edition, 10, 19-32. 

Other nonionic hydrogels Polyelectrolyte networks Interpenetrating networks... 

Nonionic hydrogels can be analyzed with Flory-Rehner theory to determine the quantitative parameters described previously. In Flory-Rehner analysis, hydrogel swelling is dictated by the thermodynamic free energies of mixing and... 

Studies of the swelling behavior of hydrogels must take into account many parameters. A differentiated view of ionic and nonionic hydrogels as well as of flie swelling behavior of hydrogels in pure water or in aqueous solutions is important... 

Even in a hydrophilic polymer, if surface density is high, a lubrication property is shown [16]. If the polymer has anionic or cationic groups, there will be ionic interaction with proteins or cells and this requires caution [17]. Adsorption of proteins or cells is difficult on a nonionic hydrogel. This has already been demonstrated by electrophoresis using a polyacrylamide gel, filtration of ce dex gel, and a cell culture on an agar gel. 

Fig. 14 A schematic diagram of adsorption of a protein and platelets onto a nonionic hydrogel having various water contents [13].

The FH theory (changes in G and F are assumed to be equivalent since the product pAV is small at low pressures) and the mbber elasticity theory follow for nonionic hydrogels ... 

In contrast to polyelectrolyte hydrogels, nonionic ones are almost insensitive to the ionic composition of the medium. In particular, the equilibrium swelling degree of a charge-free PAAm gel practically does not depend on the Cu2 + concentration (Fig. 4, curve 0) nor on the concentration of several other ions or on the pH value [101]. 

Table 1 Nonionic, Hydrophilic Monomers Used for Hydrogel Synthesis... 

Table 7 lists in four categories some of the linear polymers which can be cross-linked to form hydrogels nonionic, anionic, cationic, and ampholytic linear poly-... 

A variety of polymers including water-soluble and insoluble, ionic and nonionic hydrocolloids, and water-insoluble hydrogels can be used in bioadhesive systems [31]. The bioadhesive properties of the polymer are affected by the ... 

It has been found that the polymer surface having appropriately grafted nonionic, water-soluble polymer chains minimizes protein adsorption and cell adhesion. It should be noted that such minimum protein adsorption has been well known for a long time for hydrogels used for protein analysis such as polyacrylamine (PAAm) gel for electrophoresis, sephadex for protein gel filtration, and soft agar for cell culture. It is likely that the surface structure of these hydrogels resembles that of the grafted surface described above. 

Un-cross-linked semicrystalline poly vinyl alcohol) hydrogels were prepared by solvolysis of the corresponding vinyl trifluoroacetate polymers and copolymers. The relationships between polymer crystallinity, hydrogel structure, and mechanical properties in the subject hydrogels were examined. Evidence was presented that comonomers acted to disrupt crystal structure and increase water content. The effects of copolymer structure on surface characteristics important to biomedical applications were examined, and the importance of hydrogel nonionic character was demonstrated through protein binding studies. 

Fig. 2 (a-c) Physical polymer-network cross-linking provided by mixed micelles in hydrogels formed via hydrophobic interactions in surfactant solutions. Mixed micelles are formed by aggregation of hydrophobic blocks of per-se hydrophilic polymers and surfactant alkyl tails, (b) Nonionic polymer and ionic surfactant gel system at the state of preparation. For clarity, charges are not shown, (c) Ionic polymer and oppositely charged surfactant gel system after extraction of free micelles, (d) Structure of the hydrophobic monomers used in the micellar polymerization... 

Galaev, I. Y., Mattiasson, B. (1993). Thermoreactive water-soluble polymers, nonionic surfactants, and hydrogels as reagents in biotechnology. Enzyme and Microbial Technology, 15, 354-366. 

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