Fig. 3

A, B Intracellular uptake of PLGA NPs, PLGA-IR780 NPs, MH-PLGA NPs and MH-PLGA-IR780 NPs (labelled with DiI) in the HOS cell line as measured by CLSM and FC analysis at prolonged coincubation times. The scale bars are 50 µm. Statistical analyses of the intracellular uptake rate of the four NPs. (The data are presented as the mean ± SD value, n = 3, *p < 0.05). C, D Homologous targeting capacity of PLGA-IR780 NPs wrapped by other OS (MG63, K7M2) cell membranes. The scale bars represent 50 µm. Statistical analyses of the intracellular uptake rate of the MK-PLGA-IR780 and MM-PLGA-IR780 NPs (labelled with DiI) to MG63, K7M2 and HOS cell lines. (The data are presented as the mean ± SD values, n = 3, *p < 0.05). E, F The homologous targeting capacity of MH-PLGA-IR780 NPs (labelled with DiI) was verified by coincubation with HOS, 4T1, A549, HFOB, K7M2, MG63 and 143b cell lines for 4 h. The scale bars represent 10 µm. Statistical analyses of the intracellular uptake rate of MH-PLGA-IR780 NPs to HOS, 4T1, A549, HFOB, K7M2, MG63 and 143b cell lines. G The penetration capability of PLGA NPs, PLGA-IR780 NPs, MH-PLGA NPs and MH-PLGA-IR780 NPs in HOS 3D tumor spheroids was observed by CLSM. The scale bars represent 50 µm