Figure 4

Fluorescent images of the unseeded MDM scaffolds in meniscus tissue (MDM + Meniscus) and meniscus tissue controls (Meniscus) at day 7 (a–j) and day 28 (k–t). Initially, the meniscus tissue contains abundant cells throughout (e,j) and by day 28 cells are bridging the interface between the inner core and outer ring of meniscus tissue (o). For the samples containing the MDM scaffold inner cores (Meniscus + MDM), the meniscus outer ring contains abundant cells (a–d), and these cells are starting to populate the MDM scaffold at day 7 (f–i). By day 28, the meniscus cells fully bridge the interface (k–n) and have filled the MDM scaffold inner cores (p–s). All meniscus cells are stained green (calcein AM) and the matrix is stained red (Alexa fluor 633 NHS ester). Scale bar is 200 μm.