Effect of low cross-linked matrices on osteoblast and osteoclast.

(a) The ablation of cellular components by DOC was confirmed by DAPI staining. Bar: 50 μm. (b)The Lox activity of prepared matrices before and after the DOC treatment was analyzed. The Lox activity was significantly decreased in the matrices produced by BAPN-treated cells. DOC treatment did not significantly affect the Lox activity of prepared matrices, regardless of the BAPN concentration. (c) The proliferation of MC cells was significantly increased in the low cross-link density matrices. (d) Alkaline phosphatase (ALP) activity increased in cells seeded on low cross-linked matrices. (e) Gene expression of Cbfa1/Runx2, type I collagen α2 chain (Col1a2), alkaline phosphatase (Alpl), and osteocalcin (Spp1) significantly increased in these matrices at 3 and 7 days of culture. (f) Osteoclasts were cultured on differentially cross-linked matrices for 6 days under the differentiation condition. The number of multi-nuclear tartrate-resistant acid phosphatase (TRAP)-positive cells increased in the low cross-link density matrices. (g) Gene expression of cathepsin K (Ctsk), nuclear factor of activated T-cells cytoplasmic 1 (Nfatc1), and dendritic cell-specific transmembrane protein (DCstamp) increased in low cross-link density matrices. *p < 0.05, compared to the control.