Date(s) - 03/09/2015
The layer-by-layer approach can be used to generate finely tuned release surfaces that can release small molecule, proteins, nucleic acids and other biologic drugs over sustained time periods, and with significant control of release characteristics. Using as few as 3 or 4 bilayers to tens of layers, we can generate thin films with demonstrated therapeutic efficacy over a broad range of efficacy. Furthermore, the use of ultrathin barrier layers in between sets of multilayers can yield staged release of therapeutics from large, macroscopic surfaces such as biomedical devices and implants to microstructured arrays and nanoparticle surfaces. This approach is particularly attractive for the delivery of proteins and nucleic acids such as siRNA and DNA. By demonstrating efficacy in animal models, the promise of these material systems and their potential in biomedical applications will be highlighted. Recently, this approach has been applied to the design of structured nanoparticles that can contain siRNA in combination with chemotherapeutic drugs to achieve dual and staggered release that can synergistically attack cancer cells. The surfaces of these nanoparticles can be designed with simple polyelectrolyte pairs that yield a combination of enhanced cellular uptake at tumor microenviroment conditions, and selective targeting and uptake of tumor cells via specific receptor-ligand interactions with the native polyelectrolytes. On the other hand, siRNA and DNA can also be released from microscopic and millimeter scale structured surfaces for localized delivery directly through the skin or in the challenging environment of the wound. Multilayer “tattoos” derived from the transfer of LbL films with microneedles for transdermal delivery of DNA vaccines provides a promising route to address vaccination of difficult to target diseases. The generation of siRNA containing LbL systems for delivery to the woundbed can lead to accelerated wound healing and potential new treatments that would not be accessible using traditional polymer encapsulation methods.
Professor Paula T. Hammond is the David H. Koch Chair Professor of Engineering in the Chemical Engineering Department at the Massachusetts Institute of Technology. She is a member of MIT’s Koch Institute for Integrative Cancer Research, the MIT Energy Initiative, and a founding member of the MIT Institute for Soldier Nanotechnology. She recently served as the Executive Officer (Associate Chair) of the Chemical Engineering Department (2008-2011). The core of her work is the use of electrostatics and other complementary interactions to generate functional materials with highly controlled architecture. Her research in nanotechnology encompasses the development of new biomaterials to enable drug delivery from surfaces with spatio-temporal control. She also investigates novel responsive polymer architectures for targeted nanoparticle drug and gene delivery, and self-assembled materials systems for electrochemical energy devices.
Professor Paula Hammond was elected into the 2013 Class of the American Academy of Arts and Sciences. She is also the recipient of the 2013 AIChE Charles M. A. Stine Award, which is bestowed annually to a leading researcher in recognition of outstanding contributions to the field of materials science and engineering. She was selected to receive the Department of Defense Ovarian Cancer Teal Innovator Award in 2013, which supports a single visionary individual from any field principally outside of ovarian cancer to focus his/her creativity, innovation, and leadership on ovarian cancer research. During her sabbatical in 2013, she was a visiting scientist at the Dana-Farber Cancer Institute, and a visiting professor at the Nanyang Technological University in Singapore, in the Chemical Engineering Department. Prof. Hammond continues to serve as an Associate Editor of the American Chemical Society journal, ACS Nano. As a part of the Year of Chemistry in 2011, she was one of the Top 100 materials scientists named by Thomson-Reuters, a recognition of the highest citation impact in the field over the past decade (2001-2011). She has published over 200 papers, and holds over 20 patents based on her research at MIT. She was named a Fellow of the American Physical Society, the American Institute of Biological and Medical Engineers, and the American Chemical Society Polymer Division. In 2010, she was named the Scientist of the Year by the Harvard Foundation. Other selected honors include the Melvin Calvin Lecturer at UC Berkeley Department of Chemistry, the Margaret Etters Lecturer at the University of Minnesota, and the Caltech Kavli Distinguished Lecturer. Professor Hammond’s work on multilayer tattoos for transdermal DNA vaccines was recently featured on the PBS Nova program, “Making Stuff” with David Pogue, and she was also featured in the Chemical Heritage Foundation’s Catalyst Series: Women in Chemistry.