Application of Recellularized Non-Woven Materials from Collagen-Enriched Polylactide for Creation of Tissue-Engineered Diaphragm Constructs

Abstract

The aim of the investigation was to study biocompatibility and biomechanical properties of recellularized non-woven materials based on collagen-filled polylactide under in vitro and in vivo conditions and to assess the potential of their use for diaphragm defect replacement in the experiment on small laboratory animals. Materials and Methods. Non-woven materials were obtained by electroforming of polylactide in a tight box with subsequent specimen vacuumization. 9% aqueous solution of polylactide was prepared in the solvent mixture: chemically pure chloroform with 10% addition of chemically pure ethanol. The microfibrous material was enriched with collagen in a weight concentration of 0.1 and 0.5% with subsequent freezing at-40° or in liquid nitrogen. The structure of non-woven polylactide matrices was assessed by a scanning electron microscopy while mechanical properties were evaluated during cyclic tests for strength and fatigue properties using tensile-testing machine. The fabricated non-woven matrices were recellularized by mesenchymal stromal cells under static conditions. The quality of the fabricated tissue-engineered constructs was evaluated morphologically by routine histological investigations. The viability of the cells on the matrices and the cytotoxic properties of the matrices were determined using XTT tests. The least toxic specimens were orthotopically implanted into the rats with subsequent morphological examinations. Results. The morphological analysis and viability study of the cells on the matrices of those specimens which underwent freezing in liquid nitrogen during forming were found to be inexpedient for orthotopic transplantation. The specimens frozen in the refrigeration unit demonstrated permissible cytotoxicity levels and were implanted. The morphological examination after explantation of the given specimen groups did not reveal significant damage to the structure and inflammatory changes though the signs of the marked adhesive process in the implantation area were evident. Conclusion. In spite of the ability of the non-woven matrices to stimulate fibrinogenesis, absence of cytotoxic properties and evident reactions of transplant rejection allow the non-woven polylactide matrices undergone freezing in the refrigeration unit at-40° during the forming process to be considered promising for creation of tissue-engineered constructs of a diaphragm.

Design and fabrication of polycaprolactone/gelatin composite scaffolds for diaphragmatic muscle reconstruction

“…Some of the most often used synthetic materials used in patches for diaphragm treatment are expanded polytetrafluoroethylene patches (Grethel et al, 2006; Omura et al, 2020), reinforced silastic sheets (Smith et al, 2004), and polypropylene meshes (Mohsina et al, 2017). However, using synthetic materials may cause an allergic reaction, granulation tissue formation, infection, or mechanical insufficiencies with native tissue thoracic deformity and recurrence of the hernia (Kaarthick et al, 2017; Kuevda et al, 2019; Zhao et al, 2013). In addition, synthetic patches do not grow as the child grows (Fauza, Marler, Koka, Forse, Mayer, & Vacanti, 2001; Lantis Ii et al, 2000); hence, patients need to undergo numerous surgeries as they mature.…”