Fig. 2.

(a) Rapid diffusion (1–5 min) of FITC-labeled insulin (~6.5kD) from the microcapsules. Microcapsules containing recombinant FITC-insulin were immersed into PBS. The rapid diffusion was followed by green fluorescence under the microscope. White C, microcapsules. Arrows indicate efflux of FITC-insulin representing low molecular weight molecules. (b) The lack of influx of Alexa Fluor 488 (AF488)-labeled IgG (32kD) into microcapsules. Arrows indicate impermeability of microcapsules for AF488-IgG and other molecules (>30kD). Observation was continued for 15 min. (c) Light and fluorescent microscope images of ^GTh fibroblasts encapsulated using the phase microencapsulation technique (10×). There were approximately 500 cells per capsule. C, microcapsules. Arrow indicates a light reflection from capsule’s alginate-poly-L-lysine (AP_L) membrane, which is invisible under other imaging conditions (under fluorescent microscope or histology sections). (d) 3T3-L1 fibroblasts were differentiated into mature adipocytes for 8 days. Then acellular (empty), ^GWT, or ^GKO-containing microcapsules were added to form a monolayer of 102 microcapsules/cm². Adipocytes were incubated with microcapsules for the additional 6 days. The experiment was performed in 6-well dishes. Adipocytes were harvested in RIPA buffer (100 μL) and analyzed for triglyceride (TG) and protein content to obtain a TG/protein ratio. Data (mean ± SD, n = 3 per condition) are shown as percent of TG/protein ratio in 3T3-L1 adipocytes, which were not treated with microcapsules (none, 100%) to those treated with different microcapsules. P, significance measured by Mann–Whitney U test.