Journal: Bioactive Materials

Article Title: Smart microenvironment-adaptive nanocatalytic hydrogel for sequential antibacterial, anti-inflammatory, and regenerative therapy of biofilm-infected wounds

doi: 10.1016/j.bioactmat.2026.02.043

Figure Lengend Snippet: Characterization, and Cytocompatibility Validation of HCOC. (A) Schematic illustration of the development of HCOC. (B) FTIR spectrum of OSA, CMCS and OC hydrogel. (C) Time-dependent evolution of gelation of OC and HCOC. (D) SEM images of HCOC and EDS mapping images of C, N, O and Cu for HCOC. (E) FTIR spectra of HC, OC and HCOC. (F) Dynamic frequency sweep measurements of OC and HCOC. (G) Frequency-dependent viscoelastic behavior of OC and HCOC. (H) Alternating strain sweep with alternating strains of 1% and 1000% at 100s intervals and (I) Self-healing behavior of HCOC. (J) Live/dead staining showing the metabolic activity of L929 and RAW 264.7 cells after treatment with HCOC for 48 h. Rates of proliferation of (K) L929 cells and (L) RAW 264.7 cells after treatment with PBS or HCOC. (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001).

Article Snippet: Following the protocol of the DMAO/PI Bacterial Live/Dead Staining Kit (Beyotime Biotechnology), the bacteria were incubated with a working solution containing both DMAO and PI dyes in the dark at room temperature for 15-20 min. Fluorescence microscopy imaging was subsequently carried out.

Techniques: Biomarker Discovery, Staining, Activity Assay

Journal: Bioactive Materials

Article Title: Smart microenvironment-adaptive nanocatalytic hydrogel for sequential antibacterial, anti-inflammatory, and regenerative therapy of biofilm-infected wounds

doi: 10.1016/j.bioactmat.2026.02.043

Figure Lengend Snippet: pH Self-Adaptive Antioxidant Capacity of HCOC (Stage II: anti-inflammation). Cu ion release behavior of (A) HC (1 mg/mL) and (B) HCOC (1 mg/mL) at different pH levels. (C) ABTS + and (D) H 2 O 2 scavenging activity at different pH of Cu 5.4 O, HC and HCOC. (E) O 2 ∙ - , (F)∙OH scavenging activity of Cu 5.4 O, HAs, HC, HCOC. (G) SOD-like, (H) CAT-like and (I) GPx-like activities of HCOC. (J) Fluorescence images showing intracellular ROS detection by DCFH-DA staining, live/dead staining images and (K) cell viability of L929 cells with different treatments (All groups received 500 μM H 2 O 2 and different HCOC concentrations (I: PBS; II: 0; III: 0.25; IV: 0.50; V: 1.0 mg/mL HCOC). (L) Quantitative analysis of the cells under different treatments. (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001, ∗∗∗∗P < 0.0001) (M) Schematic illustration of pH-responsive activity and ROS scavenging and alleviating cellular oxidative stress of HCOC.

Article Snippet: Following the protocol of the DMAO/PI Bacterial Live/Dead Staining Kit (Beyotime Biotechnology), the bacteria were incubated with a working solution containing both DMAO and PI dyes in the dark at room temperature for 15-20 min. Fluorescence microscopy imaging was subsequently carried out.

Techniques: Activity Assay, Fluorescence, Staining

Journal: Bioactive Materials

Article Title: Sustained release PLGA microspheres loaded with a bone-affinity Bmp2 enhance fracture healing and mitigate heterotopic ossification

doi: 10.1016/j.bioactmat.2026.02.050

Figure Lengend Snippet: In vitro validation of D-Bmp2@M osteogenic efficacy and inhibition of ectopic ossification. a. Schematic diagram of the osteoblast-bone Transwell model. Bmp2/D-Bmp2@M microspheres or free Bmp2/D-Bmp2 were loaded in the upper chambers, MC3T3-E1 cells were cultured on two coverslips (one of which was precoated with HA) in the lower compartments, and the medium was refreshed every day for 7 or 14 days. Alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining were performed at days 7 and 14, respectively. b. Osteogenic differentiation staining: ALP (early-stage, day 7) and ARS (late-stage, day 14) staining. Scale bar: 200 μm. c. ALP activity was quantitatively analyzed using an ALP kit (n = 3 per group). d. Relative quantitative analysis of ARS staining was performed at an OD of 562 nm (n = 3 per group). e. qPCR analysis of Bmp2 signaling-related mRNA in MC3T3-E1 cells (n = 3 per group). f. Schematic diagram of the muscle-bone Transwell model. Bovine bone slices were co-incubated with Bmp2/D-Bmp2@M or free Bmp2/D-Bmp2 in the upper chambers, and C2C12 cells were cultured in the lower chambers and the medium was refreshed every day for 7 days. D-Bmp2 and Bmp2 retention on bone slices and ALP staining of C2C12 cells were analyzed on day 7. g. Representative fluorescence imaging of bone slices incubated with AF647-conjugated anti-Flag antibodies (above) (yellow arrows: bone slice) and C2C12 ALP staining images (below), scale bar: 200 μm. h. AF647-conjugated anti-Flag antibody fluorescence intensity quantification in bone slices (n = 3 per group). i. Quantification of ALP activity in C2C12 cells (n = 3 per group). j. qPCR analysis of Bmp2 signaling-related mRNA in C2C12 cells (n = 3 per group). The data are presented as the means ± SDs. One-way ANOVA was used for multiple comparisons. Significance levels: ns (not significant), ∗ p < 0.05, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001.

Article Snippet: Calcium nodules were stained with Alizarin Red S staining kit (Beyotime, China) at room temperature for 15 min, and staining conditions were monitored.

Techniques: In Vitro, Biomarker Discovery, Inhibition, Cell Culture, Staining, Activity Assay, Incubation, Fluorescence, Imaging

Journal: Bioactive Materials

Article Title: A foam cell-targeted lipophagy restoration strategy stabilizes vulnerable atherosclerotic plaques

doi: 10.1016/j.bioactmat.2026.02.041

Figure Lengend Snippet: In vivo atherosclerosis reversal. ( A ) Schematic illustration of the experimental timeline and treatment strategy for establishing a mature, vulnerable atherosclerosis model and evaluating therapeutic interventions. Mice were fed a high-fat diet (HFD) for 12 weeks and then divided into five groups (HFD+ 12W, Saline HFD+, OPN-HMCN@MLT HFD+, Saline HFD−, and OPN-HMCN@MLT HFD−). Except for the HFD+ 12W group, the remaining groups were further maintained for an additional 4 weeks under either HFD or non-HFD conditions with the indicated treatments. ( B , C ) Images of en face ORO-stained aortas ( B ) and quantitative analysis of ORO-positive regions ( C ) from mice subjected to different treatments and diets (n = 6, scale bar: 5 mm). ( D ) Aortic root sections stained by ORO, H&E, α-SMA antibody, Masson's trichrome, CD68 antibody, and MMP-9 antibody, respectively, following various therapeutic procedures (n = 6, scale bar: 500 μm). ( E - J ) Quantitative data of lipid accumulation ( E ), necrotic core area ( F ), collagen area ( G ), MMP-9 level ( H ), VSMC area ( I ), and macrophage-foam cell area ( J ) in aortic root sections. ( K ) Vulnerability scores of aortic root plaque. ∗ P < 0.05, ∗∗ P < 0.01, ∗∗∗ P < 0.001, ∗∗∗∗ P < 0.0001.

Article Snippet: Oil Red O, Hematoxylin-Eosin, and Masson's Trichrome Stain Kit were purchased from Servicebio in Wuhan, China.

Techniques: In Vivo, Saline, Staining

Journal: Bioactive Materials

Article Title: A foam cell-targeted lipophagy restoration strategy stabilizes vulnerable atherosclerotic plaques

doi: 10.1016/j.bioactmat.2026.02.041

Figure Lengend Snippet: In vivo anti-atherosclerosis effects. ( A ) Diagram illustrating the treatment protocol for apoE −/− mice. ( B , C ) En face ORO staining images and quantitative analysis of the lesion area of aortic lesion areas in apoE −/− mice following various treatments (n = 6, scale bar: 5 mm). ( D ) Quantification of the reduction ratio (versus model) of ORO-positive area to the entire aorta. ( E ) Cross-sectional images of ORO-stained aortic root (scale bars, 500 μm) and brachiocephalic artery (scale bars, 200 μm). n = 6. ( F and G ) Quantitative analysis of the aortic root lesion area ( F ) and the reduction ratio (versus model) of ORO-positive area to the aortic root ( G ). ( H ) Aortic root sections stained by H&E, α-SMA antibody, Masson's trichrome, CD68 antibody, MMP-9 antibody, and OPN antibody, respectively, following various therapeutic procedures (n = 6, scale bar: 500 μm). ( I-M ) Quantitative data of necrotic core area ( I ), collagen area ( J ), VSMC area ( K ), macrophage-foam cell area ( L ), and MMP-9 level ( M ) in aortic root sections. ( N ) Representative TEM images of LDs in the aortic root and arch of apoE −/− mice following various treatments (scale bar: 1 μm). The green arrow indicates elastic fibers. ( O-R ) Quantification of lipid droplet number and average area per cell section, n = 6. ∗ P < 0.05, ∗∗ P < 0.01, ∗∗∗ P < 0.001, and ∗∗∗∗ P < 0.0001.

Article Snippet: Oil Red O, Hematoxylin-Eosin, and Masson's Trichrome Stain Kit were purchased from Servicebio in Wuhan, China.

Techniques: In Vivo, Staining

Journal: Bioactive Materials

Article Title: A dual-functional hydrogel integrating adhesive and lubricating interfaces for mitochondrial protection–Driven cartilage regeneration

doi: 10.1016/j.bioactmat.2026.02.051

Figure Lengend Snippet: In vitro antioxidant and mitochondrial homeostasis regulatory effects of AdHy@Pae. (A) Flow cytometric analysis of the cell cycle. (B–D) Quantitative statistics of the percentage of cells in G0/G1, S, and G2/M phases. (E) JC-1 fluorescence staining. (F) Quantitative analysis of JC-1 red/green fluorescence ratio (ΔΨm). (G) Flow cytometric detection of intracellular ROS using DCFH-DA probe. Data are shown as mean ± SD (n = 3, ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001, ∗∗∗∗P < 0.0001).

Article Snippet: After LPS stimulation (10 μg mL −1 , 12 h, ServiceBio, GC205009 ) to induce an inflammatory phenotype, cells were treated with hydrogel extracts (Hy, AdHy, AdHy@Pae) for 24 h. Cells were then washed twice with PBS, harvested, and fixed overnight at 4 °C in 70% cold ethanol; after washing, they were stained with 500 μL cell-cycle staining solution (MULTI SCIENCES, CCS012) for 30 min in the dark.

Techniques: In Vitro, Fluorescence, Staining

Journal: Bioactive Materials

Article Title: Integrated fabrication of a shape-adaptable, antioxidative composite stent for effective closure and biological repair of enteroatmospheric fistula

doi: 10.1016/j.bioactmat.2026.01.014

Figure Lengend Snippet: Biocompatibility and cell migration of the composite stent. (A) Live/dead staining of IEC-6 cells cultured with the stent, showing cell viability. (B) Hemocompatibility of the stent: (i) hemolysis assay of red blood cells, (ii) corresponding hemolysis percentage. (C) Representative images of cell migration in the scratch assay. (D) Quantification of (i) migration area and (ii) percentage closure over time. (E) Representative Transwell images of migrated cells. (F) Quantification of migrated cells in the Transwell assay. Data were presented as mean ± SD (n = 3). ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001. Gel represents the G 2 S 4 hydrogel group, and Comp represents the composite stent group; the same abbreviations are used in the following figures.

Article Snippet: Live/Dead Cell Staining Kit was bought from KeyGEN BioTech (Jiangsu, China).

Techniques: Migration, Staining, Cell Culture, Hemolysis Assay, Wound Healing Assay, Transwell Assay