Biological processes such as tissue generation take place in stages that involve the release or presentation of specific molecules and the chemical and physical signaling that ensues. Diseases such as cancer, as well as chronic disorders such as auto-immune conditions, often are a result of genetic dysregulation that leads to altered cell signaling and changes in tissue microenvironment. Ideally one would be able to achieve the release of small molecule drugs as well as biochemical signals such as growth factors, or siRNA and DNA to regulate genetic code, in a manner that can respond synergistically to the body’s natural processes. This process is difficult using more traditional polymer encapsulation. Using alternating electrostatic assembly as a tool, it is possible to build ultrathin film coatings nanolayers at a time with high amounts of drug loaded, through the use of complementary electrostatic or hydrogen bonding interactions. The nature of the layering process enables the incorporation of different drugs within different regions of the thin film architecture; the result is an ability to uniquely tailor both the independent release profiles of different therapeutics from the same film, and the order of release of molecules to targeted regions of the body. Multilayered release coatings as thin as a half micron to several microns can deliver growth factor proteins in a staged manner to achieve bone regeneration across large defects, or enable integration of bone into implants with high strength interfaces. siRNA can be released directly to wounds to correct the dysregulation of wound healing processes that have gone awry, from burn and scar tissue to the closure of chronic wounds such as diabetic ulcers. New microneedle vaccines can leave multilayer nanolayer systems within the skin for controlled vaccine delivery. These concepts of combination and staged release can be translated to nanoparticle systems that deliver drugs systemically. Decoration of chemotherapy drug loaded nano-carriers with electrostatic layers that encapsulate siRNA can silence the cancer genes that enable tumor cells to resist therapy. By enabling staged release of appropriate therapeutics, it is possible to greatly enhance synergistic efficacy in lung, breast and ovarian cancer. These nanolayered complex films on large or small surfaces can replicate or complement elements of the native healing environment, and orchestrate cellular processes for improved medicine.
"Tailored Drug Release Surfaces for Regenerative Medicine and Targeted Nanotherapies", Dr. Paula Hammond, Professor, David H. Koch Chair of Engineering in Chemical Engineering Department, Massachusetts Institute of Technology.
Thursday, September 17, 2015 - 4:30pm
FCIEMAS Schiciano B