Introduction: The extension of the crosslinking degree in collagen matrices has been established as an influencing factor on the mechanical properties, surface properties, biodegradation, and cell behavior [1],[2]. The crosslinking of acellular pericardial meshes with water-soluble urethane oligomers is easily adjusted by process parameters such as pH, volume and molecular weight [3]. Subsequently, the susceptibility to the in vitro degradation and the cytotoxic potential of the soluble products appear to be dependent on the crosslinking [4]. In this work, we explore the relationship between the crosslinking extension and the performance of a biologic mesh in the reconstruction of the rodent abdominal wall tissue.
Materials and Methods: The acellular pericardial matrix [5] was crosslinked with oligourethanes synthesized from hexamethylene diisocyanate and poly(ethylene glycol) 1000 Da [4]. The ratio of oligourethane-to-matrix-to-buffered saline solution was adjusted to obtain two different extensions of crosslinking [3]. The crosslinking extension was confirmed by the ninhydrin assay. Wistar rats (male) were subjected to the surgical procedure to implant lyophilized meshes in an abdominal wall defect. The animals were euthanized at 30 days post-implantation and the implant were retrieved and rinsed with saline solution. The explanted grafts were examined for muscle integration, intraperitoneal adhesion, infection and vascularization.
Results: The crosslinking process of acellular pericardial matrix with oligourethane produces extensions of 30 and 50 % according to blocking of tissue-amines. The lyophilized meshes are easily implanted in the rodent abdominal wall. The gained weight of the male rats, 15 and 30 days post-implantation, is similar for non-crosslinked and crosslinked meshes. The new vasculature are observed on all three grafts. According to the initial size, all three grafts show stretchability after 30 days implantation. In addition, the intestinal adhesions are not observed for the hybrid graft manufactured with a crosslinking extension of 50%.
Discussion: The abdominal wall reconstruction with biologic grafts is an alternative to address the limitations of polypropylene meshes in many clinical conditions. The use of a biologic mesh crosslinked with water-soluble oligourethanes in the reconstruction, in a rodent model, of abdominal wall tissue appears to be promising in situations requiring the retarded biodegradation. This study indicated a processing-structure-property relationship in these hybrid templates that will contribute to engineer the host-graft integration.
Conclusion: Biologic meshes are crosslinked with oligourethanes to produce gradients in the crosslinking extensions. The abdominal wall defects in a rodent model are easily repaired with the hybrid meshes.
SEP-CONACYT (Grant CB2011/164440, Mexico) and Fund CIO-UG (Grant 2014 & 2015, León, Mexico).
References:
[1] K. Burugapalli, J. C. Y. Chan, J. L. Kelly, A. S. Pandit. Macromolecular Bioscience 14 (2014) 244
[2] E. C. Soller, D. S. Tzeranis, K. Miu, P. T.C. So, I. V. Yannas. Biomaterials 33 (2012) 4783
[3] B. Mendoza-Novelo, D.I. Alvarado-Castro, J. L. Mata-Mata, J. V. Cauich-Rodríguez, A. Vega-González, E. Jorge-Herrero, F. J. Rojo, G. V. Guinea. Materials Science and Engineering C 33 (2013) 2392
[4] B. Mendoza-Novelo, J. L. Mata-Mata, A. Vega-González, J. V. Cauich-Rodríguez and Á. Marcos-Fernández. Journal of Materials Chemistry B 2 (2014) 2874
[5] B. Mendoza-Novelo, E. E. Avila, J. V. Cauich-Rodríguez, E. Jorge-Herrero, F. J. Rojo, G. V. Guinea, J. L. Mata-Mata. Acta Biomaterialia 7 (2011) 1241