Development of a tannic acid and silicate ions functionalized PVA-starch composite hydrogel for in situ skeletal muscle repairing

The repair capacity of skeletal muscle is severely diminished in massive skeletal muscle injuries accompanied by inflammation, resulting in muscle function loss and scar tissue formation. In current work, we developed a tannic acid and silicate ions functionalized tissue adhesive poly (vinyl alcohol) (PVA)-starch composite hydrogel, referred as PSTS. It was formed based on the hydrogen bonds of tannic acid to organic polymers, as well as silicate-tannic acid ligand interaction. PSTS could be gelatinized in minutes at room temperature with crosslinked networks formation, making it applicable for injection. Further investigations revealed that PSTS owned skeletal muscle comparable conductivity and modulus to act as a temporary platform for muscle repairing. Moreover, PSTS could release tannic acid and silicate ions in situ to inhibit bacterial growth, induce vascularization, and reduce antioxidation, paving the possibility to create a favorable microenvironment for skeletal muscle regeneration and tissue fibrosis control. The in vivo model confirmed that PSTS could enhance muscle fibers regeneration and myotubes formation, as well as reduce infection and inflammation risk. These findings thereby implied the great potential of PSTS in the treatment of formidable skeletal muscle injuries.