Fig. 5.

Enhanced anticancer capacity of LSC-D nanoparticles under NIR laser irradiation in vitro. a Owing to the decrease of NADH by ROS oxidization in the LSC + L-treated group, the cell counting kit-8 (CCK-8) assay that relies on NADH induced color change for quantification of cell survival underestimates the cell survival for the LSC + L-treated cells. b images of live and dead stains showing that most NCI/RES-ADR cells treated with LSC + L are alive, whereas almost all the cells are dead or detached after treated with LSC-D + L. The nanoparticle concentration was 0.02-1.6 mg ml^-1. c–e Viability of NCI/RES-ADR (c) MCF-7 (d), and OVCAR-8 (e) cancer cells after treated with free DOX, LSC nanoparticles, and DOX-laden LSC (LSC-D) nanoparticles at different concentrations (0.02–1.6 mg ml⁻¹ empty nanoparticle and/or 0.5–40 µg ml⁻¹ DOX) without or with NIR laser (L) irradiation (1 W cm⁻² for 1 min) quantified using crystal violet assay. Error bars represent s.d. (n = 3). f, g Viability of NCI/RES-ADR (f) and OVCAR-8 (g) spheres enriched with CSCs after treated with free DOX together with LSC or LSC-D nanoparticles at different concentrations (0.5–40 µg ml⁻¹) without or with NIR laser irradiation by using crystal violet assay. Error bars represent s.d. (n = 3). h Images of live and dead stains showing nearly all cells are alive in spheres with the LSC + L treatment. i–j Relative NADH in NCI/RES-ADR (i) and OVCAR-8 (j) spheres showing successful inhibition NADH in LSC-treated groups with laser irradiation (LSC + L, 1 W cm⁻², 1 min). Error bars represent s.d. (n = 3). The LSC + L group is compared with the LSC group with the same LSC concentration, as well as the control and laser (alone) groups. *p < 0.05 (Kruskal–Wallis H-test). The five nanoparticle concentrations (0.02, 0.04, 0.2, 0.4, and 1.6 mg ml⁻¹) correspond to the five concentrations of DOX (0.5, 1, 5, 10, and 40 µg ml⁻¹). Control cells were cultured in medium without any treatment. Scale bars: 100 μm