Suturable mesh better resists early laparotomy failure in a cyclic ball-burst model.

PURPOSE: The small bites surgical technique supported by the STITCH trial has been touted as a strategy for preventing early laparotomy dehiscence through greater force distribution at the suture-tissue interface. However, this hernia prevention strategy requires an alteration in the standard closure technique that has not been widely adopted in the USA. This study seeks to determine whether incorporating a mid-weight polypropylene mesh material into a hollow-bore surgical suture material will effectively increase the force distribution at the suture-tissue interface and potentially help prevent early laparotomy dehiscence in an ex vivo model. METHODS: A cyclic stress ball-burst model was used to compare suturable mesh (0 DuraMesh™) to conventional suture. After midline laparotomy, 28 porcine abdominal wall specimens were closed with either 0 DuraMesh™ or #1 polydioxanone double-loop suture. A custom 3D-printed ball-burst test apparatus was used to fatigue the repair on a MTS Bionix Load Frame. The tissue was repetitively stressed at a physiological force of 15-120 N cycled at a rate of 0.25 Hz for a total of 1000 repetitions, followed by a load to failure, and the maximal force was recorded. RESULTS: The mean maximal force at suture pull-through was significantly higher (p < 0.0095) in the 0 DuraMesh suture group (mean: 850.1 N) compared to the 1 PDS group (mean: 714.7 N). CONCLUSION: This ex vivo study suggests that using rational suture design to improve force distribution at the suture-tissue interface may be a viable strategy for preventing the suture pull-through that drives incisional hernia.

The convergence of regenerative medicine and rehabilitation: federal perspectives.

Regenerative rehabilitation is the synergistic integration of principles and approaches from the regenerative medicine and rehabilitation fields, with the goal of optimizing form and function as well as patient independence. Regenerative medicine approaches for repairing or replacing damaged tissue or whole organs vary from utilizing cells (e.g., stem cells), to biologics (e.g., growth factors), to approaches using biomaterials and scaffolds, to any combination of these. While regenerative medicine offers tremendous clinical promise, regenerative rehabilitation offers the opportunity to positively influence regenerative medicine by inclusion of principles from rehabilitation sciences. Regenerative medicine by itself may not be sufficient to ensure successful translation into improving the function of those in the most need. Conversely, with a better understanding of regenerative medicine principals, rehabilitation researchers can better tailor rehabilitation efforts to accommodate and maximize the potential of regenerative approaches. Regenerative rehabilitative strategies can include activity-mediated plasticity, exercise dosing, electrical stimulation, and nutritional enhancers. Critical barriers in translating regenerative medicine techniques into humans may be difficult to overcome if preclinical studies do not consider outcomes that typically fall in the rehabilitation research domain, such as function, range of motion, sensation, and pain. The authors believe that encouraging clinicians and researchers from multiple disciplines to work collaboratively and synergistically will maximize restoration of function and quality of life for disabled and/or injured patients, including U.S. Veterans and Military Service Members (MSMs). Federal Government agencies have been investing in research and clinical care efforts focused on regenerative medicine (NIH, NSF, VA, and DoD), rehabilitation sciences (VA, NIH, NSF, DoD) and, more recently, regenerative rehabilitation (NIH and VA). As science advances and technology matures, researchers need to consider the integrative approach of regenerative rehabilitation to maximize the outcome to fully restore the function of patients.

Fractionation of an ECM hydrogel into structural and soluble components reveals distinctive roles in regulating macrophage behavior.

Extracellular matrix (ECM) derived from mammalian tissues has been utilized to repair damaged or missing tissue and improve healing outcomes. More recently, processing of ECM into hydrogels has expanded the use of these materials to include platforms for 3-dimensional cell culture as well as injectable therapeutics that can be delivered by minimally invasive techniques and fill irregularly shaped cavities. At the cellular level, ECM hydrogels initiate a multifaceted host response that includes recruitment of endogenous stem/progenitor cells, regional angiogenesis, and modulation of the innate immune response. Unfortunately, little is known about the components of the hydrogel that drive these responses. We hypothesized that different components of ECM hydrogels could play distinctive roles in stem cell and macrophage behavior. Utilizing a well-characterized ECM hydrogel derived from urinary bladder matrix (UBM), we separated the soluble and structural components of UBM hydrogel and characterized their biological activity. Perivascular stem cells migrated toward and reduced their proliferation in response to both structural and soluble components of UBM hydrogel. Both components also altered macrophage behavior but with different fingerprints. Soluble components increased phagocytosis with an IL-1RA(high), TNFα(low), IL-1ß(low), uPA(low) secretion profile. Structural components decreased phagocytosis with a PGE2(high), PGF2α(high), TNFα(low), IL-1ß(low), uPA(low), MMP2(low), MMP9(low), secretion profile. The biologic activity of the soluble components was mediated by Notch and PI3K/Akt signaling, while the biologic activity of the structural components was mediated by integrins and MEK/ERK signaling. Collectively, these findings demonstrate that soluble and structural components of ECM hydrogels contribute to the host response but through different mechanisms.