A bionic 3D-printed hydrogel microneedle of composite mesh for abdominal wall defect repair

The use of mesh repair is a frequently employed technique in the clinical management of abdominal wall defects. However, for intraperitoneal onlay mesh (IPOM), the traditional mesh requires additional fixation methods, and these severely limit its application in the repair of abdominal wall defects. We drew inspiration from the adhesion properties of mussels for the present study, functionalized carboxymethyl cellulose (CMC) with dopamine (DA), and added polyvinyl alcohol (PVA) to the composite to further improve the wet adhesive ability of hydrogels. The CMC-DA/PVA hydrogel microneedles (MNs) were fabricated using an inverse molding technique, incorporating a 3D-printed thermoplastic polyurethane mesh to enhance mechanical strength. The tensile test and porcine skin adhesion test demonstrated that the hydrogel mesh exhibited satisfactory mechanical properties and adhesion in vitro, thus replacing the traditional fixed mesh in the treatment of rat full-thickness abdominal wall defects. The results of animal experiments revealed that the hydrogel mesh promoted the growth of new granulation tissue and inhibited inflammatory responses, thereby paving the way for a novel approach in treating full-thickness abdominal wall defects.