Fd70s 100mg

MAP gels were incubated with 100 µM 70 kDa dextran-FITC (FD70S-100MG, Sigma-Aldrich) solution in PBS or a 100 nM fluorescein solution in PBS. 20µL of microgels were pipetted and annealed in a 3-mm diameter PDMS well on a glass coverslip to form a MAP scaffold. Fluorescence recovery after photobleaching (FRAP) was conducted using a Leica TCS SP5 confocal microscope. A 20x dry objective and argon laser were used for bleaching and imaging. For pore diffusivity measurements, bleaching was performed with 30% laser power and 100% transmission, with imaging at 15% transmission to limit additional bleaching. For the single-phase bleaching measurements in non-porous hydrogel and PBS, 70% laser power and 100% transmission were used for bleaching, with 6% transmission used for imaging. After bleaching for 8 seconds, at least 50 images were taken with the interval of 390 ms (Figure S2). A circle of 100 μm diameter centered on the bleach spot was taken as the analysis region of interest (ROI) in all cases using ImageJ. The diffusivity was calculated via the approach of Soumpasis ^{[44 (link)]} (1):
$$D=\frac{.224w^2}{t_{1/2}}$$
Where $w$ is the ROI radius, $t_{1/2}$ is the halftime calculated by fitting the mean intensity of the ROI in time to an exponential equation (2):
$$F\left(t\right)=a+\frac{b}{2^{{t/t}_{1/2}}}$$
Where $a$ and $b$ were obtained from the fitted curve.

8-mm disc gels were prepared as previously described in the rheology technique section. Gels were swollen in PBS overnight and placed between two slide glasses in PBS with 100 µM 70 kDa dextran-FITC (FD70S-100MG, Sigma-Aldrich). The fluorescent images of gels (FITC) were taken every day and the intensity profiles over time were used to calculate the diffusivity using Fick’s law.