PVA hydrogel

A new composite PVA hydrogel for an artificial muscle has been prepared by a freezing and thawing method [71]. The gel contained PAA and PAAm.HCl (poly-allylamine hydrochloride). The electrocontractile behavior of the composite gel in various solutions was studied. A large stroke and better controllability have been detected in a 10 mM NaOH/7 mM Ba(OH)2 system. 

Gene Expression of Cells Encapsulated in PMBV/PVA Hydrogel. 155... 

Cell-Based Biochips Fabricated Using a PMBV/PVA Hydrogel. 157... 

PMBV/PVA hydrogel Boronate/diol reaction Chemical stimulation (e.g., sugar) [40, 41]... 

Fig. 2 Concept of 3D cell engineering based on a spontaneously forming and reversible PMBV/ PVA hydrogel with high cytocompatibility as soft biodevice...

Fig. 3 Above Spontaneous gelation mechanism between the phenylboronic acid moiety (boronate ion) in water-soluble PMBV and the hydroxyl groups (diol units) in PVA. Below Photoimages of spontaneously forming PMBV/PVA hydrogel, before gelation (left), after gelation...

D-fructose (4370 M"1) > D-galactose (276 M"1) > D-glucose (110 M"1). From these results, it was confirmed that the PMBV/PVA hydrogel was formed under biological conditions, and that the reversible properties of the hydrogel corresponded to the formation of a complex between the phenylboronic acid group in PMBV and the diol moiety in PVA. 

PMBV and PVA can spontaneously form a hydrogel without using any crosslinkers. Even in cell culture conditions, the gelation can be confirmed. Therefore, it was possible to encapsulate cells in the PMBV/PVA hydrogel. The encapsulation method is illustrated in Fig. 6. 

Cell encapsulation method using PMBV/PVA hydrogel... 

Figure 9 shows the proliferation of cells encapsulated in the PMBV/PVA hydrogel. The encapsulated cells (L929) did not proliferate with the excessive proliferation seen on the TCPS. The encapsulated cells were recovered from the PMBV/PVA... 

PMBV/PVA hydrogel (filled circles) and on TCPS (circles)... 

It is hypothesized that cells proliferate uniformly and that the distribution of cell cycle phases is synchronized in the G0/G1 phase in the PMBV/PVA hydrogel. It has also been reported that cells synchronized at G0/G1 phase express a high level of cell-specific functions [59]. Thus, it is expected that the PMBV/PVA hydrogel can avoid a reduction in activity of entrapped cells and preserve cells with high functionality. 

The PMBV/PVA hydrogel containing L929 cells was prepared and incubated for 7 days. After recovery from the PMBV/PVA hydrogel, L929 cells were fixed... 

Fig. 10 Cell cycle distribution of fibroblast (L929) cells depends on the elapsed time after encapsulated in the PMBV/ PVA hydrogel and on culture time on TCPS...

Liver cells, HepG2, could also be encapsulated in the PMBV/PVA hydrogel, and the cell-specific functions were evaluated. HepG2 cells secrete albumin during cell culture. Culture supernatants were collected and albumin content measured using... 

The ES cells were encapsulated in the PMBV/PVA hydrogel by the same method used for the L929 cells. In general, ES cells form a cell aggregate called an embryoid body in suspension culture. However, it was observed that the encapsulated ES cells in the hydrogel did not form any embryoid body for 72 h. 

The PMBV/PVA hydrogel containing ES cells was dissociated by the addition of 0.2 M D-fructose solution after 3 days. After dissociation of the PMBV/PVA hydrogel, the recovered ES cells were cultured on gelatin-coated TCPS in the culture medium as usual, and the differentiation characters of recovered ES cells were estimated by alkaline phosphatase (ALP) staining (Fig. 14). 

ES cells in the PMBV/PVA hydrogel ES cells under the suspension culture... 

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