Thermo/Pressure-Sensitive Self-Fixation Surgical Meshes: The Role of Adhesive Hydrogels in Interface Attachment

Abstract

Herein, an innovative self- and pressure-adhesive biomedical implant was developed. Tissue adhesion was achieved with a thermosensitive hydrogel based on poly­(N-isopropylacrylamide-co-acrylamide), PNIPAAm-co-PAAm, grafted on a substrate composed of knitted fibers of isotactic polypropylene mesh (PP), used as surgical mesh implants. The in vitro studies, carried out with porcine skin, showed an important role of the inclusion of acrylamide-based comonomer (AAm) in the thermosensitive hydrogel PNIPAAm matrix. The bonding, peeling, and shearing energies obtained for PNIPAAm-co-PAAm increased exponentially up to three, two, and six times, respectively, compared to the gel without AAm. The physisorption and mechanical interlocking mechanisms are responsible for such improvement due to the simultaneous creation of hydrophobic and hydrophilic interactions of the thermosensitive hydrogel at temperatures higher than the lower critical solution temperature (LCST), with the porcine tissue. In addition, our bioadhesives present excellent interfacial toughness (∼100 J/m2) when compared to commercial bioglues (∼50 J/m2 or lower). The results obtained represent a very promising adhesive material that is extensible to other medical devices that require atraumatic fixation to avoid chronic pain related to other fixation approaches.