Decellularized Lymph Nodes as Scaffolds for Tissue Engineered Lymph Nodes

The lymphatic system is commonly injured during cancer treatment. However, despite the morbidity of these injuries, there are currently no options for replacing damaged lymphatics. The purpose of this study was to optimize methods for decellularization of murine lymph nodes (LN) and to determine if these scaffolds can be used to tissue engineer lymph node-like structures.

LNs were harvested from adult mice and subjected to various decellularization protocols. The degree of decellularization and removal of nuclear material was analyzed histologically and quantitatively using DNA isolation. In addition, we analyzed histological architecture by staining for matrix proteins. After the optimal method of decellularization was identified, decellularized constructs were implanted in the renal capsule of syngeneic or allogeneic recipient mice and analyzed for antigenicity. Finally, to determine if decellularized constructs could deliver lymphocytes to recipient animals, the matrices were repopulated with splenocytes, implanted in submuscular pockets, and harvested 14 days later. Decellularization was best accomplished with the detergent sodium dodecyl sulfate (SDS), resulting in negligible residual cellular material but maintenance of LN architecture. Implantation of decellularized LNs into syngeneic or allogeneic mice did not elicit a significant antigenic response. In addition, repopulation of decellularized LNs with splenocytes resulted in successful in vivo cellular delivery.

We show, for the first time, that LNs can be successfully decellularized and that these matrices have preserved extracellular matrix architecture and the potential to deliver leukocytes in vivo. Future studies are needed to determine if tissue engineered lymph nodes maintain immunologic function.