A polypropylene mesh modified with poly-ε-caprolactone nanofibers in hernia repair: large animal experiment

Barbora East,1,2 Martin Plencner,3,4 Martin Kralovic,1,3,5 Michala Rampichova,3 Vera Sovkova,1,3,5 Karolina Vocetkova,1,3,5 Martin Otahal,6,7 Zbynek Tonar,8,9 Yaroslav Kolinko,8,9 Evzen Amler,1,3,5 Jiri Hoch1,10 1Second Medical Faculty, Charles University in Prague, Prague, Czech Republic; 2Third Department of Surgery, Motol Faculty Hospital, First Medical Faculty, Charles University in Prague, Prague, Czech Republic; 3Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czech Republic; 4The Czech Academy of Sciences, Institute of Physiology, Prague, Czech Republic; 5University Centre of Energy Efficient Buildings, Czech Technical University in Prague, Bustehrad, Czech Republic; 6Department of Anatomy and Biomechanics, Faculty of Physical Education, Charles University in Prague, Prague, Czech Republic; 7Department of Natural Sciences, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic; 8Department of Histology and Embryology, 9Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic; 10Surgery Department, Motol Faculty Hospital, Second Medical Faculty, Charles University in Prague, Prague, Czech Republic Purpose: Incisional hernia repair is an unsuccessful field of surgery, with long-term recurrence rates reaching up to 50% regardless of technique or mesh material used. Various implants and their positioning within the abdominal wall pose numerous long-term complications that are difficult to treat due to their permanent nature and the chronic foreign body reaction they trigger. Materials mimicking the 3D structure of the extracellular matrix promote cell adhesion, proliferation, migration, and differentiation. Some electrospun nanofibrous scaffolds provide a topography of a natural extracellular matrix and are cost effective to manufacture.Materials and methods: A composite scaffold that was assembled out of a standard polypropylene hernia mesh and poly-ε-caprolactone (PCL) nanofibers was tested in a large animal model (minipig), and the final scar tissue was subjected to histological and biomechanical testing to verify our in vitro results published previously.Results: We have demonstrated that a layer of PCL nanofibers leads to tissue overgrowth and the formation of a thick fibrous plate around the implant. Collagen maturation is accelerated, and the final scar is more flexible and elastic than under a standard polypropylene mesh with less pronounced shrinkage observed. However, the samples with the composite scaffold were less resistant to distracting forces than when a standard mesh was used. We believe that the adverse effects could be caused due to the material assembly, as they do not comply with our previous results.Conclusion: We believe that PCL nanofibers on their own can cause enough fibroplasia to be used as a separate material without the polypropylene base, thus avoiding potential adverse effects caused by any added substances. Keywords: nanofibers, hernia, mesh, PCL, minipig, biomechanical, large anima