Fig. 2

a Chondrocyte cell proliferation when cultured with microspheres for 1, 3, and 7 days. Compared with the blank group, the L0 group promoted cell proliferation on the 7th day and the L1 group significantly promoted cell proliferation. Hydrogel loaded with sPL significantly promoted chondrocyte proliferation. b The proportion of viable cells following treatment with different microspheres (Green represents living cells, red represents dead cells); c Cell changes in cells cultured with microspheres as shown using ring pen ghost tire staining (Green indicates cell cytoskeleton, while blue indicates the nucleus); d The relative expression of chondrogenesis genes in the indicated groups. Compared with the blank group, the expression levels of type II collagen, ACAN, and SOX9 in L1 and L2 groups were significantly increased. (LK: no material and no sPL) **P < 0.0.1; ***P < 0.001; ****P < 0.0001