Efficacy of Polyhexamethylene Biguanide Antibacterial Gel Coating of Orthopedic Implants in Infection Control and Immune Modulation

With the growth of the older adult population and the increasing incidence of traumatic injuries, the use of orthopedic devices has risen significantly. However, in addition to material-related limitations, one of the most serious challenges associated with these devices is the risk of infection. To address this issue, an innovative hydrogel is presented to prevent infection at the source during orthopedic surgery. This hydrogel combines polyhexamethylene biguanide (PHMB), a positively charged agent with proven broad-spectrum antimicrobial activity, with a thermosensitive polymer. The resulting formulation provides suitable viscosity for application or dip-coating onto orthopedic devices, thereby forming a stable physical and chemical barrier. The new hydrogel exhibits temperature-responsive viscosity, which enhances both adherence and controlled release at body temperature. Additionally, the hydrogel demonstrates antibacterial effectiveness against both Gram-positive and Gram-negative bacteria, along with low cytotoxicity, minimal immune response, and excellent anti-biofouling properties. These features make the developed hydrogel well suited for orthopedic surgical procedures and support its potential as a complementary approach to reducing the risk of postoperative infections.