Polyurethane conjugating TGF-β on surface impacts local inflammation and endoplasmic reticulum stress in skeletal muscle.

The synthesized short peptide-polymers would provide key functions for tissue regeneration and repair, through enriching bioactive molecules on polymers or releasing these molecules pre-conjugated on the materials. We have developed a degradable polyurethane (PU) bearing HSNGLPL peptide, which has affinity binding ability to transforming growth factor-betas (TGF-β). For deeply understanding spatial release of TGF-β from the PU polymers and its localized bioactivity, quartz crystal microbalance (QCM) and Elisa test were used to verify TGF-β binding capacities in vitro and in vivo. The PU polymers, with or without pre-conjugating of TGF-β, were implanted into gastronomies muscle (GN) of C57BL/6 mice, for addressing TGF-β release from the polymers and its bio-regulating function in vivo. QCM result shows that PU bearing HSNGLPL peptide has affinity binding ability to TGF-β in vitro. Intramuscular implanting experiment further supports the enrichment efficiency of TGF-β on PU polymers in vivo. The detecting data involving intramuscular inflammatory infiltration triggered by the implants, myofiber regeneration, muscular fibrosis degree, and activation of endoplasmic reticulum stress (ER stress), evidence TGF-β can be released from PU polymers, and exerts regulating effects on the material-induced inflammation. Thus, our present results suggest it is feasible to improve biocompatibility of PU polymers in vivo, by pre-bearing bioactive molecules on materials before the implanting.