Associate Professor Hofstra University Bellmore, New York, United States
Introduction:: The striking similarity between animal and plant tissues has inspired a recent strategy of decellularizing plants to create scaffolds for vascular, skeletal, bone and cardiac tissue engineering. These cellulose scaffolds are inexpensive, easy to produce, and biocompatible. The purpose of this study is to determine if plant-based scaffolds are suitable for the creating robust and endothelialized small-diameter vascular grafts. Here we present a novel method of 3D vascular graft fabrication using decellularized plants that provides new and exciting applications in vascular replacement and repair.
Materials and Methods:: Leatherleaf viburnum was decellularized using 2% SDS for 72 hours, followed by a 10% bleach and 0.1% Triton X-100 solution for 8 hours. Removal of DNA was evaluated through DNA quantification and histological analysis. 3D vascular grafts were prepared by rolling the decellularized scaffolds around a 2mm rod with a gelatin and glutaraldehyde mixture. Burst pressure and tensile testing was performed for each graft. Primary rat aortic endothelial cells (ECs) were seeded into the lumen of each graft at a concentration of 1.5x10^6 cells/mL. A custom-built bioreactor was used to pre-condition these grafts with physiological fluid flow and pressures. After 5 days, DAPI staining, Scanning Electron Microscopy (SEM) and histological analysis was performed to assess the recellularization potential of the plant-based vascular grafts and the potential benefits of bioreactor pre-conditioning.
Results, Conclusions, and Discussions:: We present a novel method for generating small-caliber vascular grafts using plant-derived scaffolds and cross-linked gelatin. SDS decellularization of leatherleaf removed 97% of DNA. Burst pressure and tensile stress of grafts were comparable to native vessels (17.0±7.9 psi and 5.5±1.1 MPa). SEM and DAPI staining showed recellularized scaffolds had a confluent monolayer of ECs. Preconditioning with fluid shear stress maintained a viable cell layer on the lumen of each graft. Despite reports on potential cytotoxicity of glutaraldehyde cross-linking, thousands of implants have successfully used it clinically over the last two decades. In summary, we constructed mechanically stable vascular grafts capable of recellularization using detergent-decellularized plant leaves. Future studies will assess blood compatibility, patency, suture retention, and immune response. This approach will provide innovative uses for decellularized plant scaffolds in tissue engineering.
Acknowledgements (Optional): : Research reported here was supported by the National Institute Of Biomedical Imaging And Bioengineering of the National Institutes of Health under Award Number R15EB033168. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
