Engineering of Tracheal Grafts Based on Recellularization of Laser-Engraved Human Airway Cartilage Substrates

Abstract

Objective Implantation of tissue-engineered tracheal grafts represents a visionary strategy for the reconstruction of tracheal wall defects after resections and may develop into a last chance for a number of patients with severe cicatricial stenosis. The use of a decellularized tracheal substrate would offer an ideally stiff graft, but the matrix density would challenge efficient remodeling into a living cartilage. In this study, we hypothesized that the pores of decellularized laser-perforated tracheal cartilage (LPTC) tissues can be colonized by adult nasal chondrocytes (NCs) to produce new cartilage tissue suitable for the repair of tracheal defects. Design Human, native tracheal specimens, isolated from cadaveric donors, were exposed to decellularized and laser engraving–controlled superficial perforation (300 μm depth). Human or rabbit NCs were cultured on the LPTCs for 1 week. The resulting revitalized tissues were implanted ectopically in nude mice or orthotopically in tracheal wall defects in rabbits. Tissues were assayed histologically and by microtomography analyses before and after implantation. Results NCs were able to efficiently colonize the pores of the LPTCs. The extent of colonization (i.e., percentage of viable cells spanning >300 μm of tissue depth), cell morphology, and cartilage matrix deposition improved once the revitalized constructs were implanted ectopically in nude mice. LPTCs could be successfully grafted onto the tracheal wall of rabbits without any evidence of dislocation or tracheal stenosis, 8 weeks after implantation. Rabbit NCs, within the LPTCs, actively produced new cartilage matrix. Conclusion Implantation of NC-revitalized LPTCs represents a feasible strategy for the repair of tracheal wall defects.

Intraoperative Creation of Tissue-Engineered Grafts with Minimally Manipulated Cells: New Concept of Bone Tissue Engineering In Situ

“…To be used for tissue engineering in situ, the developed methods should ensure the isolation of a sufficient number of cells in a short time, and also not adversely affect the properties of the cells for safety reasons [ 125 ]. Extremely promising methods for enhancement of cell adhesion on scaffolds are presented by a surface micro/nano-imprinted patternization and laser engraving of surfaces of the implant [ 52 , 126 ]. It can also be hypothesized that intraoperative 3D bioprinting with the use of minimally manipulated cells will allow fast and financially affordable creation of personalized tissue-engineered constructs.…”

“…Cell adhesion may also be enhanced via modification of scaffolds, for example, scaffold immersion in deionized water [ 104 ]. Modification of the material’s surface by integrin-binding ligands and laser engraving of surfaces also led to improved cell adhesion [ 52 , 105 ].…”

“…The effectiveness of resorbable high-porous acellular hydroxyapatite scaffolds is generally based on the enhanced local regenerative potential [ 49 , 50 ]. Resorbable scaffolds could be a suitable solution for cartilage and bone tissue engineering [ 51 , 52 , 53 ]. While the mobilization of patients’ own osteoblasts leads to the revitalization of the graft, the scaffold could be completely replaced by a newly formed extracellular matrix.…”

“…Promising physical approaches allow the modification of biomaterials and cells immediately in the Operating Room (O.R.). Laser engraving of cartilage led to improved deep chondrocyte migration into the scaffold after implantation [ 52 , 61 ]. The nonselective damaged cartilage also stimulated cell migration via cell secretion activity [ 62 , 63 ].…”

Control of hydrostatic pressure and osmotic stress in 3D cell culture for mechanobiological studies

“…Integrating this basis with recent breakthroughs in tissue fabrication, biophysics, and biomaterials, should enable bottom-up strategies for the design of bioreactors that are well-suited to investigate the mechanobiology of HP and OS. Novel methods in 3D tissue bioprinting [159][160][161][162][163], mechanical characterization of biological tissues [164][165][166][167][168][169], the formulation of responsive biomaterials with tunable biomechanical and biochemical properties [170][171][172][173][174][175][176], and the development of 3D organotypic cell cultures [177][178][179][180][181][182] highlight a battery of innovations that can be exploited towards the design of advanced materials systems and bioreactors for the control of HP and OS.…”