Fig. 3: Intratumoral in situ assembly of D-NP/C-NP achieves long retention and enrichment of the NPs in the tumor site to serve as drug depots.

a IVIS imaging of 4T1 tumor-bearing mice at different times after i.v. injection of the mixture of D-NP plus C-NP (D-NP/C-NP) or S-NP plus C-NP (S-NP/C-NP) (n = 3). The NPs were labeled with DiD. White circles indicate the tumor sites. b Representative ex vivo imaging of the tumor tissues and major organs after i.v. injection of D-NP/C-NP or S-NP/C-NP at 96 h post-injection. c ROI analysis of the fluorescent signals of the collected tumor tissue and major organs in b. Data are presented as the mean ± s.d. (n = 3). Statistical significance was calculated via Student’s t-test (two-tails) in c. *p < 0.05. d Schematic showing the use of intravital CLSM to visualize the intratumoral in situ assembly and long retention of D-NP/C-NP in real time. e Intravital CLSM real-time visualization of D-NP/C-NP and S-NP/C-NP tumor accumulation in GFP-4T1 tumor-bearing mice. Both D-NP/C-NP and S-NP/C-NP were labeled with Cy5. A representative image from one of five independent fields of view in a single experiment. Source data are provided as a Source Data file.