Bone marrow transplantation is a potentially life-saving treatment for leukemia, multiple myeloma, and HIV. The procedure involves depleting the patient’s immune system, then infusing blood stem cells from a donor, which develop into a new immune system. Unfortunately, during the transplant process, patients are susceptible to disease and infection, making it risky and not recommended in certain cases.
Harvard engineers and scientists have developed an injectable, sponge-like gel that may address these challenges. The gel is designed to be injected under the skin at the time of bone marrow transplantation. Over the course of three weeks, the device becomes modified by the patient’s cells and begins to resemble spongy bone, the natural site of immune cells. The gel contains BMP-2, a protein which promotes the formation of spongy bone, and DLL-4, a protein which promotes T cell development.
After bone marrow transplantation, mice that received the gel had greater T cell proliferation than those that did not receive the gel. In addition, the mice demonstrated greater T cell diversity, a sign of improved pathogen recognition of the new immune system.
We can hope these findings lead to products that can reduce risks for future bone marrow transplant patients.
SEM cross-sections of the injectable sponge (left), and at a higher magnification showing its pore shapes and structure (right).
Top image: The bone marrow cryogel three weeks after injection. The outside is covered with a bone shell and the inside of the sponge resembles vascularized bone marrow.
Publication in Nature Biotechnology: An injectable bone marrow–like scaffold enhances T cell immunity after hematopoietic stem cell transplantation…