Biochemical and biomechanical predictors of tendon healing efficiency post-acute sports injury: A wearable biosensor and ex vivo tissue study

Tendon injuries are a leading cause of reduced mobility in athletes and remain difficult to assess due to the complex interplay between molecular healing and mechanical strength restoration. This study investigates the biochemical and biomechanical progression of tendon healing using an In vitro tendon injury model. We designed a biomimetic tendon scaffold composed of decellularized porcine collagen, which was subjected to controlled mechanical damage to simulate acute injury. The damaged scaffolds were cultured under standard conditions and monitored over a 21-day period. To track healing, we developed a flexible biosensor system capable of detecting inflammatory cytokines, specifically interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), in the surrounding media. Concurrently, we evaluated mechanical properties of the scaffold—including tensile strength, stiffness, and elasticity—using uniaxial tensile testing at predefined time points. Collagen remodeling was analyzed through hydroxyproline assays and quantification of type I and III collagen expression. Results showed a peak in IL-6 and TNF-α levels within the first 72 hours post-injury, followed by a gradual decline correlating with increased collagen deposition and improved mechanical properties. By day 21, scaffolds exhibited a 60% recovery in tensile strength and a normalized collagen type I to III ratio, suggesting biochemical resolution preceded mechanical restoration. These findings demonstrate the utility of a controlled In vitro system for studying tendon healing dynamics. The combined biochemical and biomechanical data support future development of smart rehabilitation devices and tissue-engineered therapies for musculoskeletal injuries.