Novel 3D-printed polycaprolactone/gelatin based biopatches loaded with natural antibacterial agents for hernia treatment

Incisional hernia is a common postoperative complication, particularly following abdominal surgeries, and is frequently associated with recurrence and impaired healing due to postoperative infections. In this study, a dual-layered hernia repair biopatch was developed by integrating a 3D-printed polycaprolactone/gelatin (PCL/Ge) scaffold, providing mechanical support, with an electrospun nanofibrous layer composed of PCL/Ge/<i>κ</i>-carrageenan (<i>κ</i>-C) to promote wound healing. To impart antimicrobial functionality, the scaffolds were functionalized with either<i>Agrimonia eupatoria</i>(AE) extract or the clinically used antibiotic rifampicin (RIF). Commercial polypropylene (PP) meshes were employed as control groups in both<i>in vitro</i>and<i>in vivo</i>evaluations. Mechanical testing demonstrated that the developed biopatches exhibited tensile strengths within a clinically relevant range, with values of 5.13 MPa and 2.49 MPa for the 3D-printed RIF-loaded and AE-loaded electrospun-coated scaffolds, respectively. Both AE- and RIF-loaded groups showed pronounced antibacterial activity against<i>S. aureus</i>, a predominant pathogen associated with surgical site infections. Sustained and controlled release profiles were observed over 160 h, with cumulative release values of approximately 30%-35%.<i>In vivo</i>evaluation using a rat incisional hernia model revealed that AE exhibits strong potential as an alternative to conventional antibiotics, attributable to its phenolic-rich composition and associated anti-inflammatory and tissue-remodeling properties. Overall, these findings demonstrate that the proposed dual-layer biopatch, which integrates mechanical reinforcement with sustained antimicrobial activity, represents a promising and effective strategy for infection-resistant incisional hernia repair.