Rapidly gelling platelet-rich plasma-loaded carboxymethyl hydroxybutyl chitosan hydrogel for colonic repair and adhesion reduction

Colonic wound repair remains limited by poor material adhesion and postoperative intra-abdominal adhesions. Platelet-rich plasma (PRP) was incorporated into an externally supplied thermosensitive carboxymethyl hydroxybutyl chitosan (CHC) matrix to prepare a composite hydrogel for colonic wound repair. CHC remains fluid at 4 °C, allowing homogeneous mixing with PRP at a 4:1 ratio while preserving growth factor bioactivity. Upon exposure to 37 °C, the mixture rapidly gels within 10 s, achieving a shear adhesive strength of 75 kPa, sufficient to withstand intestinal pressure fluctuations and enable sustained growth factor release. In rat and New Zealand rabbit full-thickness colonic defect models, the composite hydrogel significantly accelerated mucosal repair and reduced postoperative adhesions. Mechanistically, PRP activated the PI3K/Akt pathway, promoting macrophage polarization toward the M2 phenotype and shifting cellular metabolism toward Oxidative Phosphorylation, thereby establishing a local anti-inflammatory microenvironment. Together, the strong tissue adhesion of CHC and the immunomodulatory function of PRP provide a promising sutureless strategy for repairing high-risk intra-abdominal visceral injuries.