Particles are stable until inside cells
Multilamellar vesicles that remain stable outside of cells but release their cargo once they are within cells are showing promise as whole-protein vaccines, researchers at the Massachusetts Institute of Technology (MIT) reported. The nanoparticles may also be effective for carrying drugs to tumors, according to the lead researcher.
Liposomes are very leaky structures. We wanted to stabilize the liposomes by fusing them into multilamellar structures and then forming chemical crosslinks between the vesicles, said James J. Moon, PhD, a postdoctoral associate in the immunobioengineering laboratory led by Darrell J. Irvine, PhD, an associate professor in the department of materials science and engineering at MIT.
Dr. Moon is first author and Dr. Irvine senior author of a paper describing the multilamellar vesicles in Nature Materials (Moon JJ, Suh H, Bershteyn A, et al. Nat Mater. 2011;10(3):243-251 [ from Moon JJ, Suh H, Bershteyn A, et al. Nat Mater. 2011;10(3):243-251 ).
The nanoparticles, called interbilayer-crosslinked multilamellar vesicles, entrapped protein antigens and lipophilic immunostimulatory molecules stably under extracellular conditions but rapidly released them in the presence of endolysosomal lipases, the researchers reported. Carrying the combination of antigen and adjuvant, the particles evoked immune responses comparable to live viral vaccine vectors.
We have shown that our particles can effectively deliver the protein antigens to dendritic cells and macrophages in lymph nodes. They trigger strong cellular as well as humoral immune responses, Dr. Moon said in an interview.
There may also be applications for delivery of chemotherapy, he said. Although we haven t tested it yet, particles loaded with chemotherapeutics may be taken up by cancer cells and rapidly release the drugs in cytosol, he added.
Source: pharmaquality
