Journal: Bioactive Materials

Article Title: A multimodal ROS logic-gated therapeutic platform disrupts the vicious cycle of senescence to promote aged bone defect repair

doi: 10.1016/j.bioactmat.2026.02.002

Figure Lengend Snippet: Anti-senescence effects of the hydrogel platform on BMSCs. (A) Schematic diagram illustrating hallmark differences between senescent and rejuvenated BMSCs. (B) qRT-PCR analysis of senescence-related genes ( p16 , p21 , p53 ) after different treatments ( n = 3). (C) Western blot analysis of p16, p21, and p53 protein expression in senescent BMSCs. (D) Corresponding quantitative analysis of protein expression ( n = 3). (E) Representative immunofluorescence images of p53 staining in BMSCs (scale bars: 90 μm). (F) Quantitative analysis of p53 fluorescence intensity ( n = 3). (G) Representative cell cycle distribution plots obtained by flow cytometry. (H) Statistical analysis of S-phase ( n = 3). (I) Representative SA- β -gal staining images of senescent BMSCs (scale bars: 200 μm). (J) Quantification of SA- β -gal positive cells ( n = 3). (K) qRT-PCR analysis of SASP-associated genes ( Ccl2 , Mmp2 , Il-6 , Tnf-α ) in BMSCs ( n = 3). Data are presented as mean ± SD; ∗ P < 0.05, ∗∗ P < 0.01, ∗∗∗ P < 0.001.

Article Snippet: Tissue sections were stained for γ-H2A.X (Servicebio, GB111841 , 1:500), p62 (Affinity, AF5384, 1:500), p16 (Santa Cruz, sc-81156, 1:200), p21 (Affinity, AF6290, 1:300), Cyclin D1 (Proteintech, 26939-1-AP, 1:200), MMP-2 (Servicebio, GB11130, 1:500), IL-6 (Servicebio, GB11117, 1:200), and TNF-α (Servicebio, GB115702 , 1:200) following standard protocols.

Techniques: Quantitative RT-PCR, Western Blot, Expressing, Immunofluorescence, Staining, Fluorescence, Flow Cytometry

Journal: Bioactive Materials

Article Title: Microenvironment-educated MSC-EVs loaded injectable smart hydrogel for targeting senescent nucleus pulposus cells and inhibiting ferroptosis against intervertebral disc degeneration

doi: 10.1016/j.bioactmat.2026.02.030

Figure Lengend Snippet: Senescent Microenvironment-Educated Mesenchymal Stem Cells Release High-Affinity Senescent NPC Domesticated Extracellular Vesicles. (A) Schematic diagram of the experimental setup for educating MSCs with SASP-CM to generate D-EVs versus N-EVs. (B) Confocal microscopy images showing different EVs internalization by senescent NPCs after 12 h in vitro. (C) Flow cytometry and quantification analysis of different EVs uptake by senescent NPCs. (D) In vivo validation of the senescent niche. Representative fluorescence images following injection of senescence-tracer (Red). (E) In vivo PKH26-labeled D-EVs tracking. (F) Representative SA-β-Gal images and quantification of MSCs treated with SASP-CM or not. (G) Gene Ontology (GO) analysis confirming enrichment of external encapsulating structure organization and cytokine production in Biological Process (BP) categories. (H) Heatmap indicating gene expression associated with EVs biogenesis within D-MSCs and N-MSCs. (I) Heatmap indicating gene expression associated with cytokine production within D-MSCs and N-MSCs. (J and L) Gene Ontology (GO) analysis confirming enrichment of terms related to vesicle organization and transport in the Cellular Component (CC) categories. (K) Western blot analysis confirmed core senescence markers p16 and p21 and DNA damage marker γ-H2AX in N-MSC and D-MSC. (M) Western blot analysis confirmed the expression of CD9, CD63, TSG101, Calnexin, and GM130 in MSC-EVs, N-EVs, or D-EVs. (N) TEM images showing the morphology and size of MSC-derived EVs, N-EVs, and D-EVs. (O) NTA shows size distribution in MSC-EVs, N-EVs, or D-EVs. The data were presented as mean ± SD. n = 3, ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After blocked with 5% non-fat milk for 2 h at room temperature, the membranes were incubated with primary antibodies against GAPDH (1:5000, 104941-AP, Proteintech), TSG101 (1:1000, DF8427, Affinity), CD9 (1:1000, AF5139, Affinity), CD63 (1:2000, 25682-1-AP, Proteintech), Calnexin (1:5000, 10427-2-AP, Proteintech), GM130 (1:20000, 11308-1-AP, Proteintech), CXCR3 (1:5000, 26756-1-AP, Proteintech), CXCL10 (1:2000, 10937-1-AP, Proteintech), MMP3 (1:2000, 17873-1-AP, Proteintech), ADAMTS5 (DF13268, Affinity), P16 (AF5484, Affinity), P21 (10355-1-AP, Proteintech), GPX4 (1:1000, 381958, Zen-bio), SLC7A11 (1:1000, 26864-1-AP, Proteintech), ACSL4 (1:5000, 22401-1-AP, Proteintech) and Tubulin (1:10000, T40103 , Abmart) overnight at 4 °C.

Techniques: Confocal Microscopy, In Vitro, Flow Cytometry, In Vivo, Biomarker Discovery, Fluorescence, Injection, Labeling, Gene Expression, Western Blot, Marker, Expressing, Derivative Assay

Journal: Bioactive Materials

Article Title: Microenvironment-educated MSC-EVs loaded injectable smart hydrogel for targeting senescent nucleus pulposus cells and inhibiting ferroptosis against intervertebral disc degeneration

doi: 10.1016/j.bioactmat.2026.02.030

Figure Lengend Snippet: D-EVs Alleviate Cellular Senescence and Restore ECM anabolic/catabolic metabolism in Senescent NPCs. (A) The CCK8 assay was used to determine D-EVs concentrations on cell viability. (B) Flow cytometry analysis of proliferative capacity in the above group, and (C) quantitative analysis. (D) Representative ROS images of senescent NPCs treated with N-EVs, D-EVs, or D-EVs + GW4869. (E) Representative SA-β-Gal images of senescent NPCs treated with N-EVs, D-EVs, or D-EVs + GW4869, and (F) quantitative analysis. (G) Confocal analysis of γ-H2A with IF staining depicting DNA damage in the control, TBHP, N-Evs, or D-EVs group. (H) WB analysis of ECM metabolism–related and aging-related proteins in NPCs following treatment with Control, TBHP, N-Evs, or D-EVs. (I) Western blot analysis of p53, p21, and p16 in senescent NPCs treated with D-EVs, D-CM, or D-CM EV-dep . (J) Confocal analysis of COL2 with IF staining in the control, TBHP, N-EVs, or D-EVs group. The data were presented as mean ± SD. n = 3, ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After blocked with 5% non-fat milk for 2 h at room temperature, the membranes were incubated with primary antibodies against GAPDH (1:5000, 104941-AP, Proteintech), TSG101 (1:1000, DF8427, Affinity), CD9 (1:1000, AF5139, Affinity), CD63 (1:2000, 25682-1-AP, Proteintech), Calnexin (1:5000, 10427-2-AP, Proteintech), GM130 (1:20000, 11308-1-AP, Proteintech), CXCR3 (1:5000, 26756-1-AP, Proteintech), CXCL10 (1:2000, 10937-1-AP, Proteintech), MMP3 (1:2000, 17873-1-AP, Proteintech), ADAMTS5 (DF13268, Affinity), P16 (AF5484, Affinity), P21 (10355-1-AP, Proteintech), GPX4 (1:1000, 381958, Zen-bio), SLC7A11 (1:1000, 26864-1-AP, Proteintech), ACSL4 (1:5000, 22401-1-AP, Proteintech) and Tubulin (1:10000, T40103 , Abmart) overnight at 4 °C.

Techniques: CCK-8 Assay, Flow Cytometry, Staining, Control, Western Blot

Journal: Bioactive Materials

Article Title: Microenvironment-educated MSC-EVs loaded injectable smart hydrogel for targeting senescent nucleus pulposus cells and inhibiting ferroptosis against intervertebral disc degeneration

doi: 10.1016/j.bioactmat.2026.02.030

Figure Lengend Snippet: D-EVs Counteract NPC Senescence by Suppressing Ferroptosis. (A) KEGG pathway analysis of DEGs in senescent NPCs following treatment with D-EVs or not. (B-C) GSEA plots showing significant enrichment of ferroptosis and cell cycle in senescent NPCs. (D-E) Heatmap quantification of key genes involved in ferroptosis and cell cycle. (F) Western blot analysis of key ferroptosis (GPX4, SLC7A11, ACSL4) and senescence (p21, P16) markers in NPCs following treatment with different experimental conditions. (G) Representative images of C11-BODIPY 581/591 staining to detect lipid peroxidation (green) in the control, TBHP, Era, Era + Fer-1, or TBHP + Fer-1 groups. (H-I) Quantitative assessment of malondialdehyde (MDA) levels (H) and glutathione (GSH) levels (I) in the control, TBHP, N-EVs, D-EVs, or D-EVs + Era groups. (J) Western blot analysis of key ferroptosis (GPX4, SLC7A11, ACSL4) and senescence (p21, P16) markers in NPCs following treatment with PBS, N-EVs, D-EVs, or D-EVs + Era. (K) Confocal analysis of GPX4 with IF staining in the control, TBHP, N-Evs, D-EVs, and D-EVs + Era group. (L) Flow cytometry analysis of cell cycle distribution in the above experimental conditions. Statistical comparisons were performed between the experimental group and the TBHP-induced group. The data were presented as mean ± SD. n = 3, ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After blocked with 5% non-fat milk for 2 h at room temperature, the membranes were incubated with primary antibodies against GAPDH (1:5000, 104941-AP, Proteintech), TSG101 (1:1000, DF8427, Affinity), CD9 (1:1000, AF5139, Affinity), CD63 (1:2000, 25682-1-AP, Proteintech), Calnexin (1:5000, 10427-2-AP, Proteintech), GM130 (1:20000, 11308-1-AP, Proteintech), CXCR3 (1:5000, 26756-1-AP, Proteintech), CXCL10 (1:2000, 10937-1-AP, Proteintech), MMP3 (1:2000, 17873-1-AP, Proteintech), ADAMTS5 (DF13268, Affinity), P16 (AF5484, Affinity), P21 (10355-1-AP, Proteintech), GPX4 (1:1000, 381958, Zen-bio), SLC7A11 (1:1000, 26864-1-AP, Proteintech), ACSL4 (1:5000, 22401-1-AP, Proteintech) and Tubulin (1:10000, T40103 , Abmart) overnight at 4 °C.

Techniques: Western Blot, Staining, Control, Flow Cytometry

Journal: Bioactive Materials

Article Title: Microenvironment-educated MSC-EVs loaded injectable smart hydrogel for targeting senescent nucleus pulposus cells and inhibiting ferroptosis against intervertebral disc degeneration

doi: 10.1016/j.bioactmat.2026.02.030

Figure Lengend Snippet: D-EVs Deliver GPX4 to Inhibit Ferroptosis in Senescent NPCs. (A) Representative Senescent-Tracker images of NPCs treated with N-EVs, D-EVs, Era, and D-Evs sh-CXCL10 . (B) Volcano plot of transcriptomic data comparing D-MSC and N-MSC. (C) KEGG pathway analysis of DEGs in D-MSCs versus N-MSCs. (D) Volcano plot of proteomic data comparing D-EVs and N-EVs. (E) KEGG pathway analysis of transcriptomic and proteomic data integration. (F) A Venn diagram illustrating the intersection of genes from the D-MSC transcriptome, the D-EVs proteome, and the ferroptosis-related gene set. (G) Bar graph showing the relative expression levels of core overlapping genes identified in (F). (H) MS analysis revealed that GPX4 is enriched in the D-EVs proteome. (I) Western blot analysis confirming GPX4 protein in D-EVs and N-EVs. (J) Western blot analysis of key senescence (p21, P16) markers in NPCs following treatment with PBS or N-EVs with CXCL10 or GPX4 knockout. (K) Representative images of EdU depicting cell proliferation ability in the control, TBHP, D-EVs, D-EVs sh-CXCL10 , D-EVs sh-GPX4 , and D-EVs sh-CXCL10+GPX4 groups. (L-M) Confocal images showing GPX4 delivery from different EVs to senescent NPCs at 12h and 24h co-culture, and (N) colocalization analysis. The data were presented as mean ± SD. n = 3, ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After blocked with 5% non-fat milk for 2 h at room temperature, the membranes were incubated with primary antibodies against GAPDH (1:5000, 104941-AP, Proteintech), TSG101 (1:1000, DF8427, Affinity), CD9 (1:1000, AF5139, Affinity), CD63 (1:2000, 25682-1-AP, Proteintech), Calnexin (1:5000, 10427-2-AP, Proteintech), GM130 (1:20000, 11308-1-AP, Proteintech), CXCR3 (1:5000, 26756-1-AP, Proteintech), CXCL10 (1:2000, 10937-1-AP, Proteintech), MMP3 (1:2000, 17873-1-AP, Proteintech), ADAMTS5 (DF13268, Affinity), P16 (AF5484, Affinity), P21 (10355-1-AP, Proteintech), GPX4 (1:1000, 381958, Zen-bio), SLC7A11 (1:1000, 26864-1-AP, Proteintech), ACSL4 (1:5000, 22401-1-AP, Proteintech) and Tubulin (1:10000, T40103 , Abmart) overnight at 4 °C.

Techniques: Expressing, Western Blot, Knock-Out, Control, Co-Culture Assay

Journal: Bioactive Materials

Article Title: On-demand mild photothermal cascade platform reprogramming mitochondrial immunity for tendon rejuvenation

doi: 10.1016/j.bioactmat.2026.01.004

Figure Lengend Snippet: LT-NPs-NIR protects TSPCs against oxidative stress-induced senescence and preserves tenogenic phenotype. (A–D) Immunofluorescence staining for DNA damage (γ-H2AX), proliferation (Ki67), and senescence markers (P16, P53). (E–G) Assessment of stemness (SOX2) and tenogenic differentiation markers (SCX, COL1). (H) Quantitative analysis of the indicated markers. (I) qRT-PCR analysis of SASP-related inflammatory mediators (IL-1β, CXCL10) and matrix-degrading enzymes (MMP3, MMP13). (J) Schematic illustrating the mechanism of ROS scavenging and SASP inhibition. Significance: ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. Snt: senescent cells; Yng: young cells.

Article Snippet: After washing, cells were incubated with primary antibodies against Ki67 (ab15580, Abcam), Phosphorylated Histone H2AX (γ-H2AX) (ab81299, Abcam), SOX2 (sc-365964, Santa Cruz), Type I Collagen (COL1) (ab138492, Abcam), tenomodulin (TNMD) (ab203676, Abcam; sc-51813, Santa Cruz), Scleraxis (SCX) (sc-518082, Santa Cruz), IRF3 (ab68481, Abcam), Transcription Factor p65/RELA (P65) (A22331, Abclonal), Cyclin-Dependent Kinase Inhibitor 2A (p16INK4a) (P16) (sc-1661, Santa Cruz), P53 (10442-1-AP, Proteintech), Inducible Nitric Oxide Synthase (iNOS) (ab178945, Abcam), Arginase-1(Arg-1) (ab96183, Abcam), HSP70 (sc-32239, Santa Cruz), IL-6 (ab233706, Abcam), Matrix Metalloproteinase 13 (MMP13) (ab39012, Abcam), Double-stranded DNA (dsDNA) Marker (sc-58749, Santa Cruz), and Translocase of Outer Mitochondrial Membrane 20 (TOMM20) (11802-1-AP, Proteintech).

Techniques: Immunofluorescence, Staining, Quantitative RT-PCR, Inhibition

Journal: Bioactive Materials

Article Title: On-demand mild photothermal cascade platform reprogramming mitochondrial immunity for tendon rejuvenation

doi: 10.1016/j.bioactmat.2026.01.004

Figure Lengend Snippet: LT-NPs-NIR modulate macrophage polarization and enhance TSPC-mediated tenogenic repair in a Transwell co-culture system. (A) Schematic of the Transwell co-culture setup. (B) SA-β-gal staining of macrophages. (C–F) Immunofluorescence of TSPCs for (C) P16, (D) SOX2, (E) SCX, and (F) Tenomodulin (TNMD) with F-actin. (G) Quantification of P16, SOX2, SCX, and TNMD levels. (H) Proposed mechanism: LT-NPs-NIR promote an M1-to-M2 macrophage shift and regulate TSPC senescence/stemness balance to favor tenogenic repair, potentially via STING/NF-κB signaling. Scale bars: 100 μm (B); 50 μm (C–E); 100 μm (F). Significance: ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After washing, cells were incubated with primary antibodies against Ki67 (ab15580, Abcam), Phosphorylated Histone H2AX (γ-H2AX) (ab81299, Abcam), SOX2 (sc-365964, Santa Cruz), Type I Collagen (COL1) (ab138492, Abcam), tenomodulin (TNMD) (ab203676, Abcam; sc-51813, Santa Cruz), Scleraxis (SCX) (sc-518082, Santa Cruz), IRF3 (ab68481, Abcam), Transcription Factor p65/RELA (P65) (A22331, Abclonal), Cyclin-Dependent Kinase Inhibitor 2A (p16INK4a) (P16) (sc-1661, Santa Cruz), P53 (10442-1-AP, Proteintech), Inducible Nitric Oxide Synthase (iNOS) (ab178945, Abcam), Arginase-1(Arg-1) (ab96183, Abcam), HSP70 (sc-32239, Santa Cruz), IL-6 (ab233706, Abcam), Matrix Metalloproteinase 13 (MMP13) (ab39012, Abcam), Double-stranded DNA (dsDNA) Marker (sc-58749, Santa Cruz), and Translocase of Outer Mitochondrial Membrane 20 (TOMM20) (11802-1-AP, Proteintech).

Techniques: Co-Culture Assay, Staining, Immunofluorescence

Journal: Bioactive Materials

Article Title: On-demand mild photothermal cascade platform reprogramming mitochondrial immunity for tendon rejuvenation

doi: 10.1016/j.bioactmat.2026.01.004

Figure Lengend Snippet: Molecular assessment of tendon repair and systemic biosafety. (A) Representative immunofluorescence images of inflammatory, matrix-degrading, tenogenic, and senescence markers, alongside macrophage phenotypes in repaired tendons. (B) Correlation analysis integrating molecular and functional recovery. Bar charts (left Y-axis) display the relative fluorescence intensity of the indicated markers, overlaid with line graphs (right Y-axis) showing the fold change in biomechanical properties (Ultimate Load and Tensile Modulus). Note the inverse correlation between SASP factors (IL-6, MMP13, P16) and mechanical strength. (C) Western blot analysis of the STING pathway, senescence indicators, and heterotopic ossification markers (OCN, SOX9, BMP-2). (D, E) Systemic biosafety evaluation via H&E staining of major organs (D) and blood biochemistry analysis (E) showing no toxicity. Significance: ns, not significant; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: After washing, cells were incubated with primary antibodies against Ki67 (ab15580, Abcam), Phosphorylated Histone H2AX (γ-H2AX) (ab81299, Abcam), SOX2 (sc-365964, Santa Cruz), Type I Collagen (COL1) (ab138492, Abcam), tenomodulin (TNMD) (ab203676, Abcam; sc-51813, Santa Cruz), Scleraxis (SCX) (sc-518082, Santa Cruz), IRF3 (ab68481, Abcam), Transcription Factor p65/RELA (P65) (A22331, Abclonal), Cyclin-Dependent Kinase Inhibitor 2A (p16INK4a) (P16) (sc-1661, Santa Cruz), P53 (10442-1-AP, Proteintech), Inducible Nitric Oxide Synthase (iNOS) (ab178945, Abcam), Arginase-1(Arg-1) (ab96183, Abcam), HSP70 (sc-32239, Santa Cruz), IL-6 (ab233706, Abcam), Matrix Metalloproteinase 13 (MMP13) (ab39012, Abcam), Double-stranded DNA (dsDNA) Marker (sc-58749, Santa Cruz), and Translocase of Outer Mitochondrial Membrane 20 (TOMM20) (11802-1-AP, Proteintech).

Techniques: Immunofluorescence, Functional Assay, Fluorescence, Western Blot, Staining