Fig. 4: Isolation and detection of EVs with in vivo MGL.

a Schematic schedule of the in vivo MGL in a 4T1 tumor-bearing mouse model. b Protocol diagram of the collection process for tissue-derived EVs. c Schematic of the detection of biotin-linked MGL CD63⁺ EVs and the detected distribution in plasma and different tissue samples. The fluorescence detection was on CD63⁺ EVs from plasma, tumor tissue and other major organs of 4T1 tumor-bearing mice with MGL, as well as CD63⁺ EVs from plasma and tumor tissue of 4T1 tumor-bearing mice without MGL. ΔFL = FL – FL₀, where FL₀ and FL are the fluorescence intensity detected by Melac-Chip before and after the addition of sample. n = 5 biologically independent experiments. Data shown as mean ± SD. d Schematic of the detection of biotin-linked MGL PD-L1⁺ EVs. e The detected fluorescence intensity of PD-L1⁺ EVs from plasma samples of 4T1 tumor-bearing mice (n = 3 biologically independent experiments) with different injection manners of Ac₄ManNAz. I. t. refers to intratumoral injection and i. p. refers to intraperitoneal injection. Data shown as mean ± SD. f The detected fluorescence intensity of PD-L1⁺ EVs from plasma samples of normal mice and 4T1 tumor-bearing mice with Ac₄ManNAz treatment (n = 5 biologically independent experiments). Data are presented as mean values ± SD. g Normalized PD-L1 fluorescence intensity of plasma samples (n = 3 biologically independent experiments) from 4T1 tumor-bearing mice at 0, 1, 2, 3 and 4 d injection of Ac₄ManNAz (once/day). “3 d + and 7 d -” indicates a stop for 7 days after 3 consecutive days of injection. Data shown as mean ± SD. Statistical significance was determined using Tukey’s Method with One-Way ANOVA. P = 0.1063 (0 d vs 1 d), and P = 0.0005 (0 d vs 2 d). ***P < 0.001, and n.s. indicates non-significance (P > 0.05). Source data are provided as a Source Data file.