Quantifying the role of hyaluronic acid on collagen fiber mechanics via femtosecond laser ablation

Low molecular weight methacrylated hyaluronic acid (MeHA) restores collagen fiber recoil in HA-depleted and aged murine tendons toward adult control levels, linking HA to fiber sliding.

• Why it matters: HA is widely used for tendon injuries, but its contribution to tendon fiber-scale mechanics and viscoelastic relaxation is not well quantified.
• What they did: The team combined femtosecond laser ablation, second harmonic generation imaging, and mechanical testing to measure collagen fiber recoil in intact murine tendons, then modeled relaxation with quasi-linear viscoelastic analysis.
• The result: Aging and enzymatic HA depletion reduced elastic, viscoelastic, and total collagen fiber recoil, while MeHA diffusion with photocrosslinking recovered recoil and revealed HA-dependent relaxation changes not captured by macroscale mechanics.

AI summary of the abstract · may contain errors · not medical advice · read the paper.