Electrostatic layer-by-layer (LBL) process, is a simple and elegant method of creating designer biomaterials systems that can �shed� their layers to release drugs in a controlled and systematic fashion.    It is possible to use these systems to engage cells in vitro and in vivo, and manipulate cellular behavior for biomaterials and biomedical applications.   We demonstrate the ability to modulate drug release over periods of several weeks to months in sequence through the use of nanomaterials as separating barrier layers between multilayers loaded with different delivery agents.  Such nanolayered systems can be used to induce the migration of cells to materials surfaces, enhance their adhesion these surfaces, and promote proliferation or differentiation of cells to create new tissue.   Furthermore, we have recently developed systems that allow direct release of siRNA to tissues, including challenging biological environments such as open wounds.    In these cases, siRNA is released in a highly sustained fashion to tissue over several days, leading to significant and consistent knockdown in localized areas. Applications of multilayer thin films for bone tissue engineering and implant coatings as well as wound healing will be discussed.   On the other hand, it is possible to design nanoparticles that consist of several nanolayers wrapped around a core materials system.   The resulting polyelectrolyte nanolayer assemblies can �surf� the bloodstream without being taken up by the monocyte-phagoctytic system,  enabling their accumulation in tumors, where siRNA, molecular inhibitors and chemotherapy drugs can be released together or in controlled sequence.   These siRNA nanoparticles in motion can be thought of as carriers with specific addresses:  they have been designed to induce cells to take them up in the tumor site based on environmental triggers or molecular targeting.   Finally, in this context, a new approach to the design of siRNA nanoparticles based on the generation of poly-siRNA generated with rolling circle transcription will be discussed.  This approach enables the use of RNA nanotechnology to generate siRNA that self-assembles with itself or other components to create pre-formed nanoparticle systems.

Tuning surfaces for cellular function, motion and uptake using nanolayer assemblies

246th National Meeting (2013)

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