In vitro PTT with the scaffolds. (a) Tumor cell killing effect of the CS/nHA/CD and CS/nHA scaffolds with or without 808 nm laser irradiation for 10 min. (b) Confocal laser scanning microscopy images of live/dead stained tumor cells with different treatments. (i-iv) CS/nHA/CD+NIR, CS/nHA+NIR, CS/nHA/CD, and CS/nHA, respectively. Most cells were dead (red) in the CS/nHA/CD+NIR group, indicating an excellent tumor ablation effect. (c) SEM images of the tumor cells with different treatments. (i-iv) CS/nHA/CD+NIR, CS/nHA+NIR, CS/nHA/CD, and CS/nHA, respectively. Tumor cells were swollen, and the cell membrane was damaged (highlighted by white arrows) in the CS/nHA/CD +NIR group, whereas they showed normal morphology in the other groups. Each value is the mean ± standard deviation; *p < 0.05, **p < 0.01.