Fig. 4

Characterisation of biologically relevant properties of PVA cryogels for bioprocess applications. Diffusion of glycerol and glutamate (candidate substrate molecules) in conventional and transparent PVA cryogels quantified at 35 °C, in terms of the effective diffusion coefficient, Deff (a). Reference aqueous diffusion coefficients, D, are indicated by labelled dotted lines. Error bars represent SD of 2 replicates. Biocompatibility of cryogels was determined by comparing cell viability before and after immobilisation in PVA cryogel beads under continuous cultivation (b). Cell-membrane integrity is used as proxy for cell viability, expressed as percentage intact cells:total cells as measured by LIVE/DEAD staining and CLSM. Error bars represent SEM for minimum of 3 samples with 3–4 images each; datapoints shown as grey symbols. Statistical significance for one-way ANOVA with Tukey’s multiple comparison indicated by ****p < 0.0001; ***p < 0.001; **p < 0.01; *p < 0.05; ns not significant