Journal: Bioactive Materials
Article Title: Glycosaminoglycan-functionalized hydrogels for sustained delivery of tissue inhibitor of metalloproteinase-3 mediating matrix metalloprotease inhibition and extracellular matrix stabilization
doi: 10.1016/j.bioactmat.2026.02.010
Figure Lengend Snippet: TIMP-3 from GelMA/sHAc hydrogels reduces matrix degradation ex-vivo. (A) Schematic overview of the ex-vivo matrix degradation assay. Human dentin slices were demineralized to expose the collagen matrix and activate endogenous proteases and subsequently incubated with TIMP-3-containing or TIMP-3-free hydrogels to assess their effects on native matrix degradation. (B) The potential of TIMP-3 released from hydrogels after 24 and 168 h to influence native matrix turnover was analyzed in an ex-vivo dentin slice model using the EnzChek assay, in comparison to hydrogels without TIMP-3. Demineralized dentin slices without additional treatment served as controls (Ctrl). (C) Collagen degradation by endogenous matrix-located proteases was assessed in the presence or absence of hydrogel released TIMP-3 or hydrogels without TIMP-3. Collagen preservation was measured by Sirius red staining followed by dye elution. Inactivated dentin slices from autoclaved teeth served as reference. One-way ANOVA: ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001., For (A) a = ∗∗∗p < 0.001 vs. Ctrl, for (B) b = ∗∗∗p < 0.001 vs. Reference. Significant differences were determined versus Ctrl/Reference and between hydrogels with or without TIMP-3 of the same composition to distinguish material-from TIMP-3-specific effects. (D, E) TIMP-3-loaded GelMA/sHA c hydrogels reduce ECM degradation in a human ex-vivo skin model. (D) Schematic of the ex-vivo human skin model. 10 mm skin biopsies with a 4 mm wound were collected within 24 h post-mortem and cultured ex-vivo. Pathological ECM degradation was induced by collagenase and TNF-α treatment. GelMA/sHA c hydrogels with or without TIMP-3 were applied to the wound surface and cultured for 72 h. (E) Overview of sample groups and representative Sirius red-stained histological sections showing ECM organization: intact wound (no pathological ECM degradation), wound with induced ECM degradation treated with GelMA/sHA c , or GelMA/sHA c + TIMP-3. The wound region is indicated by a dotted line. (F) Remaining collagen content quantified by Sirius red staining of human skin samples, followed by dye elution and absorbance measurement. Absorbance values were corrected for initial sample weight differences. One-way ANOVA: ∗∗p < 0.01, ∗∗∗p < 0.001.
Article Snippet: To stimulate protease secretion, cells were treated with 20 ng/mL human recombinant TNF-α (Bio-Techne, Wiesbaden, Germany) for 48 h. The supernatants were collected and used to determine the protease activity in the presence or absence of soluble HA c and sHA c with or without additional TIMP-3 or hydrogel extracts as described in section “cytotoxicity of hydrogel extracts” using the EnzChek Gelatinase/Collagenase Assay Kit (Fisher Scientific, Schwerte, Germany) according to the manufacturer's protocol.
Techniques: Ex Vivo, Degradation Assay, Incubation, Comparison, Preserving, Staining, Cell Culture