Fig 1: PCH and PHS promote osteoclast formation and resorption by osteoclasts. A) TRAP staining images of osteoclasts on PCL, PCH, or PHS sheets after seven days of stimulation using M‐CSF and RANKL. S, PCL, PCH, or PHS sheets. 1) Cells around the sheet. 2) Cells on the surface of the sheet. Black arrows, osteoclasts. Red arrows, osteoclast precursors. B) SEM images of osteoclasts and their resorption lacunae on the surface of the sheet. C,D) Count of osteoclasts around C) and on the surface of D) the sheet, n = 3. E,F) Areas of osteoclasts around E) and on the surface of F) the sheet, n = 3. G) Analysis of resorption area. H) Measurement of lacune depth. I) TRAP staining images of the calcified cartilaginous matrix in rats with large‐segment bone defects implanted with PCL, PCH, or PHS at 4 weeks. Black arrows, osteoclasts. Red arrows, calcified cartilaginous matrix. J–M) Statistical analysis of osteoclast formation‐related mRNA expression, including Trap J), Nfatc1 K), Ctsk L), and C‐fos M), n = 3. All data are expressed as the mean ± SD. For C–H) and J–M), statistical analysis was performed using one‐way ANOVA with Tukey's multiple comparison tests. ns, no significant difference. ***p < 0.001.