FIG. 4.

Alginate–fibrin microbeads degradation and cell release. (A-C) Optical photos at 1, 7, and 14 days. A blue filter was used to enhance the contrast of the microbeads. Arrows in B and C indicate cell release from the microbeads. (D-G) Live/dead staining images of the bottom CPC surface. (D) At 7 days, some cells showed as green dots, indicating that they were still encapsulated in the fragments of microbeads. Other cells had a spread, spindled morphology, indicating that they were released and attached to CPC. (E) The spread morphology at 14 days. (F) At 21 days, the number of attached cells increased. (G) For comparison, alginate microbeads without fibrin did not degrade, with the cells remaining as green dots, and did not spread at 21 days. (H) Scanning electron microscopy (SEM) micrograph of released cells attaching to the CPC bottom surface. Arrows indicate the cytoplasmic extensions of the cells. Color images available online at www.liebertonline.com/tea