Page 52 - ASME_NEMB_2016_Program

Technical Program TRACK 4

This talk will report results of our recent studies on understanding the under- Technical Presentation. NEMB2016-5988
lying self-assembling processes in living systems used to generate unique
nano-scale mechanical and photonic phenomena for realizing biological Ying Li, zhiqiang Shen, University of Connecticut, Storrs, CT, United
functions, including high-strength adhesive and fluorescent properties. States
Examples will be presented to illustrate how these processes can be manip-
ulated to fabricate fluorescent peptide nanoparticles and tunable adhesive Through nanomedicine, game-changing methods are emerging to deliver
hydrogels for regenerative medicine.
drug molecules directly to diseased areas. One of the most promising of
these is the targeted delivery of drugs and imaging agents via drug carri-
4:30pm Designing Biological Interactions of DNA-Assembled er-based platforms. Such drug delivery systems can now be synthesized
Nanoparticle Superstructures from a wide range of different materials, made in a number of different
shapes, and coated with an array of different organic molecules, including
Technical Presentation. NEMB2016-5959 ligands. If optimized, these systems can enhance the efficacy and specificity
of delivery compared those of non-targeted systems. Up to date, there are
Leo Chou, Dana-Farber Cancer Institute, Boston, MA, United several classes of nanoparticles (NPs) demonstrating the promising prop-
States, Kyryl Zagorovsky, Vahid Raeesi, Warren Chan, University erties as therapeutic carriers, such as solid lipid NPs, liposomes, quantum
dots, dendrimers and polymer micelles. By loading the drug molecules
of Toronto, Toronto, ON, Canada into these NPs, their bio-distribution, pharmacokinetics and toxicity can be
dramatically improved, in comparison to their freely administrated counter-
Nanoparticle drug delivery systems must overcome a series of physiologi- parts. In this work, we have computationally designed a novel drug carrier,
cal barriers to reach their sites-of-action. Although the in vivo behaviour of Au-Polyethylene glycol-lipid NP. This NP is formed by the self-assembly of
engineered nanomaterials can be tuned as a function of their physical pa- the Au- Polyethylene glycol NPs, with random lipid molecules. Large scale
rameters, design principles developed for one behavior often diverge from coarse-grained molecular simulations have been performed to understand
another. In other words, it is likely that the optimal size, shape, and surface how the grafting density and molecular weight of tethered chains will affect
chemistry of nanoparticles for traversing physiological barriers must evolve the formed Au-Polyethylene glycol-lipid NPs. It has been found that the
with their location and time within the body. To address this challenge, we Au-Polyethylene glycol-lipid NPs could be more easily self-assembled when
explored the construction of dynamic nanoparticle systems, using DNA the grafting density and molecular weight of polyethylene glycol are en-
assembly as tool for prototyping. We postulated that DNA programmability larged and reduced, respectively. The phase diagram, in terms of the graft-
provides stringent control over the structure and dynamics of nanomaterials ing density and molecular weight of tethered polyethylene glycol chains, is
for controlling their interactions with biological systems. Here, we describe also computationally constructed, which could be used to guide experimen-
how DNA-assembled nanoparticle superstructures interact with serum tal synthesis of these Au-Polyethylene glycol-lipid NPs. The endocytosis of
proteins, cells, and tissues as a function of their design, specifically in the Au-Polyethylene glycol-lipid NPs is further explored through molecular simu-
context of drug delivery and discuss emerging strategies for therapeutic lations and compared with liposomes.
design.
5:10pm Exploring the Impact of Local Ligand Flexibility on B Lym-
Our study used spherical and rod-shaped metal nanoparticles of varying
sizes (e.g. 3, 5, and 15 nm) as models. We functionalized these nanopar- phocyte Signaling via a Platform DNA Origami Nanostructure
ticles with oligonucleotides and poly(ethylene glycol) as ligands, and
combined them in different combinations using complementary oligonucle- Technical Presentation. NEMB2016-6008
otides linkers to form superstructures with distinct architectures. We charac-
terized these materials using dynamic light scattering and electron micros- Christopher Lucas, Emily N. Briggs, Randy A. Patton, Molly Y.
copy, followed by a systematic assessment of their interactions with serum Mollica, John C. Byrd, Virginia M. Sanders, The Ohio State Uni-
proteins, cells, and tissues. Superstructure interactions with serum were versity, Columbus, OH, United States, Carlos Castro, Ohio State
analyzed by polyacrylamide gel electrophoresis (PAGE); cellular uptake university, Columbus, OH, United States
and biodistribution was measured by inductively-coupled atomic emission
spectroscopy, and visualized by electron microscopy and whole-animal
fluorescence imaging. Scaffolded DNA origami molecular self-assembly allows for the generation
of two- and three-dimensional DNA nanostructures that may be functional-
ized in a highly specific manner with biological molecules to induce molecu-
Our results show that DNA assembly can synthesize a large number of lar and cellular responses that may be studied at the single cell scale. Previ-
nanoparticle superstructures with controlled size, surface chemistry, and
architectures. Architecture was especially important in determining the ous work demonstrated that the level of intracellular signaling is dependent
accessibility of ligands to nuclease degradation and recognition by macro- upon ligand proximity, an effect that may be controlled through the employ-
phages. In essence, it determines what the biological system “sees” when ment of DNA nanostructures. However, whether local flexibility of a specific
encountering a superstructure nanomaterial. By controlling architecture ligand affects the level of intracellular signal generated within single B cells
remains unexplored. Here we describe the generation of a Ligand Presen-
and surface chemistry of the superstructures, we were able to engineer
DNA-linked superstructures that are serum stable for up to 8 hours and tation Platform (LPP) DNA nanostructure that allows for precise control of
resist macrophage uptake and sequestration. In vivo, these design opti- the number, spatial arrangement, and local flexibility via the length of linker
mizations improved superstructure accumulation within a tumor xenograft attaching the ligand to the platform. The ligand linker is a single-stranded
model, and permitted tumour-specific imaging contrast at 24 hours post-in- biotinylated DNA oligo that extends from the nanostructure allowing for
streptavidin and biotinylated anti-CD40 antibody attachment and precise
jection. We also investigated the use of DNA assembly to integrate pho-
tothermal gold nanorods and the chemotherapeutic doxorubicin into su- control over ligand linker length. Well-formed LPP DNA nanostructures were
perstructures. This design strategy placed DNA melting and consequently confirmed via agarose gel electrophoresis, transmission electron microsco-
superstructure integrity under optical control, thereby allowing light-trig- py, and atomic force microscopy. Effective streptavidin and biotin-labeled
gered drug release and intracellular uptake. Overall, we showed that DNA anti-CD40 antibody incorporation to LPP DNA nanostructures was assessed
by fluorescent agarose gel electrophoresis and transmission electron mi-
assembly of dynamic nanoparticle systems permits emerging therapeutic
design strategies as well as new ways to design their interactions with bio- croscopy. In addition, fluorescent microscopy experiments revealed that an-
logical systems. ti-CD40 functionalized LPP DNA nanostructures attached to the CH12.LX B
cell surface in a specific manner relative to a species-/isotype-matched con-
trol antibody functionalized LPP nanostructure. Our initial functional experi-
4:50pm Computational study on self-assembly of Au-Polyeth-
52 ylene glycol-lipid nanoparticles ments revealed that immobilization of an anti-CD40 antibody on a platform
DNA nanostructure induced significant increases in NF-kappaB activation in
single murine CH12.LX B cells relative to soluble antibodies at equal concen-
trations. Furthermore, the strength of signal induction of CD40-dependent