In Vitro-In Vivo Correlation for the Degradation of Tetra-PEG Hydrogel Microspheres with Tunable β-Eliminative Crosslink Cleavage Rates

Figure 6

Loss of gel components as a function of . (a) Fractional fluorescence () remaining at the injection site as a normalized function of for 13 different hydrogel microspheres having values ranging from 12 to 2750 hours and (black square) or (red circle). The data were grouped into clusters having a median of , and vertical lines show the deviation of the measured parameter within each cluster. Theoretical curves were calculated according to equation 3 where and . (b) Fit of the clustered ultrasound volumes of materials E-M (Table S1) to equation 4 using  mm³ and . Error bars represent the standard deviation of the clustered volume data.

(a)

(b)