Engineered Decellularized Tendon Matrix Putty Preserves Native Tendon Bioactivity to Promote Cell Proliferation and Enthesis Repair

Figure 4

(a) DTM reconstituted and stretched to demonstrate the viscoelasticity of the DTM. (b) DTM reconstituted. (c) Oscillation stress sweep of human DTM with concentrations of 0, 1, 3, 5, and 7 g of lyophilized DTM to 1 mL of PBS resulted in all reconstitution concentrations tested to maintain an elastic modulus (n = 1 donor, 2-3 runs each). (d) Collagenase activity was measured to confirm successful removal of the added collagenase solution during enzymatic digestion. No significant differences were observed in collagenase activity between native tendon and enzymatically digested and filtered samples ( = 0.922; n = 3–10 donors). (e) The total protein of the samples was tested to confirm bioactivity was maintained (n = 4 donors) and no significant differences were found between native, DTM, and pepsin samples. An ordinary one-way ANOVA was conducted to determine statistical significance in collagenase activity and treatment groups, F (4, 22) = 18.06,  < 0.0001, and in total protein content between groups, F (2, 9) = 5.282,  = 0.0304. Additional significance from Tukey’s multiple comparison is listed on graphs (d) and (e).