1
|
Najeh S, Zandi K, Kharma N, Perreault J. Computational design and experimental verification of pseudoknotted ribozymes. RNA (NEW YORK, N.Y.) 2023; 29:764-776. [PMID: 36868786 PMCID: PMC10187678 DOI: 10.1261/rna.079148.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/27/2022] [Indexed: 05/18/2023]
Abstract
The design of new RNA sequences that retain the function of a model RNA structure is a challenge in bioinformatics because of the structural complexity of these molecules. RNA can fold into its secondary and tertiary structures by forming stem-loops and pseudoknots. A pseudoknot is a set of base pairs between a region within a stem-loop and nucleotides outside of this stem-loop; this motif is very important for numerous functional structures. It is important for any computational design algorithm to take into account these interactions to give a reliable result for any structures that include pseudoknots. In our study, we experimentally validated synthetic ribozymes designed by Enzymer, which implements algorithms allowing for the design of pseudoknots. Enzymer is a program that uses an inverse folding approach to design pseudoknotted RNAs; we used it in this study to design two types of ribozymes. The ribozymes tested were the hammerhead and the glmS, which have a self-cleaving activity that allows them to liberate the new RNA genome copy during rolling-circle replication or to control the expression of the downstream genes, respectively. We demonstrated the efficiency of Enzymer by showing that the pseudoknotted hammerhead and glmS ribozymes sequences it designed were extensively modified compared to wild-type sequences and were still active.
Collapse
Affiliation(s)
- Sabrine Najeh
- INRS - Institut Armand-Frappier, Laval, QC H7V 1B7, Canada
| | - Kasra Zandi
- Software Engineering and Computer Science Department, Concordia University, Montreal, Quebec H3G 1M8, Canada
| | - Nawwaf Kharma
- Electrical and Computer Engineering Department, Concordia University, Montreal, Quebec H3G 1M8, Canada
| | | |
Collapse
|
2
|
Hartung J, McCann N, Doe E, Hayth H, Benkato K, Johnson MB, Viard M, Afonin KA, Khisamutdinov EF. Toehold-Mediated Shape Transition of Nucleic Acid Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2023; 15:25300-25312. [PMID: 37204867 PMCID: PMC10331730 DOI: 10.1021/acsami.3c01604] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We introduce a toehold-mediated strand displacement strategy for regulated shape-switching of nucleic acid nanoparticles (NANPs) enabling their sequential transformation from triangular to hexagonal architectures at isothermal conditions. The successful shape transitions were confirmed by electrophoretic mobility shift assays, atomic force microscopy, and dynamic light scattering. Furthermore, implementation of split fluorogenic aptamers allowed for monitoring the individual transitions in real time. Three distinct RNA aptamers─malachite green (MG), broccoli, and mango─were embedded within NANPs as reporter domains to confirm shape transitions. While MG "lights up" within the square, pentagonal, and hexagonal constructs, the broccoli is activated only upon formation of pentagon and hexagon NANPs, and mango reports only the presence of hexagons. Moreover, the designed RNA fluorogenic platform can be employed to construct a logic gate that performs an AND operation with three single-stranded RNA inputs by implementing a non-sequential polygon transformation approach. Importantly, the polygonal scaffolds displayed promising potential as drug delivery agents and biosensors. All polygons exhibited effective cellular internalization followed by specific gene silencing when decorated with fluorophores and RNAi inducers. This work offers a new perspective for the design of toehold-mediated shape-switching nanodevices to activate different light-up aptamers for the development of biosensors, logic gates, and therapeutic devices in the nucleic acid nanotechnology.
Collapse
Affiliation(s)
- Jordan Hartung
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Nathan McCann
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Erwin Doe
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Hannah Hayth
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Kheiria Benkato
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - M Brittany Johnson
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Mathias Viard
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, United States
- Basic Science Program, Leidos Biomedical Research Inc. National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Kirill A Afonin
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Emil F Khisamutdinov
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| |
Collapse
|
3
|
Trammell SR. Light-Assisted Drying for the Thermal Stabilization of Nucleic Acid Nanoparticles and Other Biologics. Methods Mol Biol 2023; 2709:117-130. [PMID: 37572276 DOI: 10.1007/978-1-0716-3417-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Abstract
Cold-chain storage can be challenging and expensive for the transportation and storage of biologics, especially in low-resource settings. Nucleic acid nanoparticles (NANPs) are an example of new biological products that require refrigerated storage. Light-assisted drying (LAD) is a new processing technique to prepare biologics for anhydrous storage in a trehalose amorphous solid matrix at ambient temperatures. Small volume samples (10 μL) containing NANPs are irradiated with a 1064 nm laser to speed the evaporation of water and create an amorphous trehalose preservation matrix. In previous studies, samples were stored for 1 month at 4 °C or 20 °C without degradation. A FLIR SC655 mid-IR camera is used to record the temperature of samples during processing. The trehalose matrix was characterized using polarized light imaging to determine if crystallization occurred during processing or storage. Damage to LAD-processed NANPs was assessed after processing and storage using gel electrophoresis.
Collapse
Affiliation(s)
- Susan R Trammell
- Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, NC, USA.
| |
Collapse
|
4
|
Anh Lam P, Furr DP, Tran A, McKeough RQ, Beasock D, Chandler M, Afonin KA, Trammell SR. The Application of Light-Assisted Drying to the Thermal Stabilization of Nucleic Acid Nanoparticles. Biopreserv Biobank 2022; 20:451-460. [PMID: 36067075 PMCID: PMC9603253 DOI: 10.1089/bio.2022.0035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Cold-chain storage can be challenging and expensive for the transportation and storage of biologics, especially in low-resource settings. Nucleic acid nanoparticles (NANPs) are an example of new biological products that require refrigerated storage. Light-assisted drying (LAD) is a new processing technique to prepare biologics for anhydrous storage in a trehalose amorphous solid matrix at ambient temperatures. In this study, LAD was used to thermally stabilize four types of NANPs with differing structures and melting temperatures. Methods: Small volume samples (10 μL) containing NANPs were irradiated with a 1064 nm laser to speed the evaporation of water and create an amorphous trehalose preservation matrix. Samples were then stored for 1 month at 4°C or 20°C. A FLIR C655 mid-IR camera was used to record the temperature of samples during processing. The trehalose matrix was characterized using polarized light imaging (PLI) to determine if crystallization occurred during processing or storage. Damage to LAD-processed NANPs was assessed after processing and storage using gel electrophoresis. Results: Based on the end moisture content (EMC) as a function time and the thermal histories of samples, a LAD processing time of 30 min is sufficient to achieve low EMCs for the 10 μL samples used in this study. PLI demonstrates that the trehalose matrix was resistant to crystallization during processing and after storage at 4°C and at room temperature. The native-polyacrylamide gel electrophoresis results for DNA cubes, RNA cubes, and RNA rings indicate that the main structures of these NANPs were not damaged significantly after LAD processing and being stored at 4°C or at room temperature for 1 month. Conclusions: These preliminary studies indicate that LAD processing can stabilize NANPs for dry-state storage at room temperature, providing an alternative to refrigerated storage for these nanomedicine products.
Collapse
Affiliation(s)
- Phuong Anh Lam
- Department of Physics and Optical Science and University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Daniel P. Furr
- Department of Physics and Optical Science and University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Allison Tran
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Riley Q. McKeough
- Department of Physics and Optical Science and University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Damian Beasock
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Morgan Chandler
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Kirill A. Afonin
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Susan R. Trammell
- Department of Physics and Optical Science and University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| |
Collapse
|
5
|
Wang H, Guo P. Radiolabeled RNA Nanoparticles for Highly Specific Targeting and Efficient Tumor Accumulation with Favorable In Vivo Biodistribution. Mol Pharm 2021; 18:2924-2934. [PMID: 34212728 DOI: 10.1021/acs.molpharmaceut.1c00035] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Therapeutic efficiency and toxicity are two of the three critical factors in molecular therapy and pharmaceutical drug development. Specific tumor targeting and rapid renal excretion contribute to improving efficiency and reducing toxicity. We recently found that RNA nanoparticles display rubber-like properties, enabling them to deliver therapeutics to cancer with high efficiency. Off-target RNA nanoparticles were rapidly cleared by renal excretion, resulting in nontoxicity. However, previous biodistribution studies relied mainly on fluorescent markers, which can cause interference from fluorophore quenching and autofluorescence. Thus, the quantification of biodistribution requires further scrutiny. In this study, radionuclide [3H] markers were used for quantitative pharmacokinetic (PK) studies to elucidate the favorable PK profile of RNA nanoparticles. Approximately 5% of [3H]-RNA nanoparticles accumulated in tumors, in contrast to the 0.7% tumor accumulation reported in the literature for other kinds of nanoparticles. The amount of [3H]-RNA nanoparticles accumulated in tumors was higher than that in the liver, heart, lung, spleen, and brain throughout the entire process after IV injection. [3H]-RNA nanoparticles rapidly reached the tumor vasculature within 30 min and remained in tumors for more than 2 days. Nontargeting [3H]-RNA nanoparticles were found in the urine 30 min after IV injection without degradation and processing, and more than 55% of the IV-injected radiolabeled RNA nanoparticles were cleared from the body within 12 h, while the other 45% includes the radiative counts that cannot be recovered due to whole-body distribution and blood dilution after intravenous injection. The high specificity of tumor targeting, fast renal excretion, and low organ accumulation illustrate the high therapeutic potential of RNA nanoparticles in cancer treatment as efficient cancer-targeting carriers with low toxicity and side effects.
Collapse
Affiliation(s)
- Hongzhi Wang
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| |
Collapse
|
6
|
Li H, Zhang K, Binzel DW, Shlyakhtenko LS, Lyubchenko YL, Chiu W, Guo P. RNA nanotechnology to build a dodecahedral genome of single-stranded RNA virus. RNA Biol 2021; 18:2390-2400. [PMID: 33845711 DOI: 10.1080/15476286.2021.1915620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The quest for artificial RNA viral complexes with authentic structure while being non-replicative is on its way for the development of viral vaccines. RNA viruses contain capsid proteins that interact with the genome during morphogenesis. The sequence and properties of the protein and genome determine the structure of the virus. For example, the Pariacoto virus ssRNA genome assembles into a dodecahedron. Virus-inspired nanotechnology has progressed remarkably due to the unique structural and functional properties of viruses, which can inspire the design of novel nanomaterials. RNA is a programmable biopolymer able to self-assemble sophisticated 3D structures with rich functionalities. RNA dodecahedrons mimicking the Pariacoto virus quasi-icosahedral genome structures were constructed from both native and 2'-F modified RNA oligos. The RNA dodecahedron easily self-assembled using the stable pRNA three-way junction of bacteriophage phi29 as building blocks. The RNA dodecahedron cage was further characterized by cryo-electron microscopy and atomic force microscopy, confirming the spontaneous and homogenous formation of the RNA cage. The reported RNA dodecahedron cage will likely provide further studies on the mechanisms of interaction of the capsid protein with the viral genome while providing a template for further construction of the viral RNA scaffold to add capsid proteins for the assembly of the viral nucleocapsid as a model. Understanding the self-assembly and RNA folding of this RNA cage may offer new insights into the 3D organization of viral RNA genomes. The reported RNA cage also has the potential to be explored as a novel virus-inspired nanocarrier.
Collapse
Affiliation(s)
- Hui Li
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH, USA.,College of Pharmacy, The Ohio State University, Columbus, OH, USA.,James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Kaiming Zhang
- Department of Bioengineering and James H. Clark Center, Stanford University, Stanford, CA, USA
| | - Daniel W Binzel
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH, USA.,College of Pharmacy, The Ohio State University, Columbus, OH, USA.,James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Lyudmila S Shlyakhtenko
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Yuri L Lyubchenko
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Wah Chiu
- Department of Bioengineering and James H. Clark Center, Stanford University, Stanford, CA, USA.,Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH, USA.,College of Pharmacy, The Ohio State University, Columbus, OH, USA.,James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| |
Collapse
|
7
|
Badu S, Melnik R, Singh S. Mathematical and computational models of RNA nanoclusters and their applications in data-driven environments. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1804564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Shyam Badu
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Roderick Melnik
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, Waterloo, Ontario, Canada
- BCAM-Basque Center for Applied Mathematics, Bilbao, Spain
| | - Sundeep Singh
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, Waterloo, Ontario, Canada
| |
Collapse
|
8
|
Su C, Weir JD, Zhang F, Yan H, Wu T. ENTRNA: a framework to predict RNA foldability. BMC Bioinformatics 2019; 20:373. [PMID: 31269893 PMCID: PMC6610807 DOI: 10.1186/s12859-019-2948-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND RNA molecules play many crucial roles in living systems. The spatial complexity that exists in RNA structures determines their cellular functions. Therefore, understanding RNA folding conformations, in particular, RNA secondary structures, is critical for elucidating biological functions. Existing literature has focused on RNA design as either an RNA structure prediction problem or an RNA inverse folding problem where free energy has played a key role. RESULTS In this research, we propose a Positive-Unlabeled data- driven framework termed ENTRNA. Other than free energy and commonly studied sequence and structural features, we propose a new feature, Sequence Segment Entropy (SSE), to measure the diversity of RNA sequences. ENTRNA is trained and cross-validated using 1024 pseudoknot-free RNAs and 1060 pseudoknotted RNAs from the RNASTRAND database respectively. To test the robustness of the ENTRNA, the models are further blind tested on 206 pseudoknot-free and 93 pseudoknotted RNAs from the PDB database. For pseudoknot-free RNAs, ENTRNA has 86.5% sensitivity on the training dataset and 80.6% sensitivity on the testing dataset. For pseudoknotted RNAs, ENTRNA shows 81.5% sensitivity on the training dataset and 71.0% on the testing dataset. To test the applicability of ENTRNA to long structural-complex RNA, we collect 5 laboratory synthetic RNAs ranging from 1618 to 1790 nucleotides. ENTRNA is able to predict the foldability of 4 RNAs. CONCLUSION In this article, we reformulate the RNA design problem as a foldability prediction problem which is to predict the likelihood of the co-existence of a sequence-structure pair. This new construct has the potential for both RNA structure prediction and the inverse folding problem. In addition, this new construct enables us to explore data-driven approaches in RNA research.
Collapse
Affiliation(s)
- Congzhe Su
- School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, AZ 85281 USA
| | - Jeffery D. Weir
- Department of Operational Sciences, Graduate School of Engineering and Management, Air Force Institute of Technology, Wright-Patterson AFB, Dayton, OH 45433 USA
| | - Fei Zhang
- Biodesign Center for Molecular Design and Biomimetics, The Biodesign Institute & School of Molecular Sciences, Arizona State University, Tempe, AZ 85281 USA
| | - Hao Yan
- Biodesign Center for Molecular Design and Biomimetics, The Biodesign Institute & School of Molecular Sciences, Arizona State University, Tempe, AZ 85281 USA
| | - Teresa Wu
- School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, AZ 85281 USA
| |
Collapse
|
9
|
Chandler M, Afonin KA. Smart-Responsive Nucleic Acid Nanoparticles (NANPs) with the Potential to Modulate Immune Behavior. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E611. [PMID: 31013847 PMCID: PMC6523571 DOI: 10.3390/nano9040611] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 03/29/2019] [Accepted: 04/08/2019] [Indexed: 12/24/2022]
Abstract
Nucleic acids are programmable and biocompatible polymers that have beneficial uses in nanotechnology with broad applications in biosensing and therapeutics. In some cases, however, the development of the latter has been impeded by the unknown immunostimulatory properties of nucleic acid-based materials, as well as a lack of functional dynamicity due to stagnant structural design. Recent research advancements have explored these obstacles in tandem via the assembly of three-dimensional, planar, and fibrous cognate nucleic acid-based nanoparticles, called NANPs, for the conditional activation of embedded and otherwise quiescent functions. Furthermore, a library of the most representative NANPs was extensively analyzed in human peripheral blood mononuclear cells (PBMCs), and the links between the programmable architectural and physicochemical parameters of NANPs and their immunomodulatory properties have been established. This overview will cover the recent development of design principles that allow for fine-tuning of both the physicochemical and immunostimulatory properties of dynamic NANPs and discuss the potential impacts of these novel strategies.
Collapse
Affiliation(s)
- Morgan Chandler
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
| | - Kirill A Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
| |
Collapse
|
10
|
Guo S, Li H, Ma M, Fu J, Dong Y, Guo P. Size, Shape, and Sequence-Dependent Immunogenicity of RNA Nanoparticles. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 9:399-408. [PMID: 29246318 PMCID: PMC5701797 DOI: 10.1016/j.omtn.2017.10.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/14/2017] [Accepted: 10/14/2017] [Indexed: 02/01/2023]
Abstract
RNA molecules have emerged as promising therapeutics. Like all other drugs, the safety profile and immune response are important criteria for drug evaluation. However, the literature on RNA immunogenicity has been controversial. Here, we used the approach of RNA nanotechnology to demonstrate that the immune response of RNA nanoparticles is size, shape, and sequence dependent. RNA triangle, square, pentagon, and tetrahedron with same shape but different sizes, or same size but different shapes were used as models to investigate the immune response. The levels of pro-inflammatory cytokines induced by these RNA nanoarchitectures were assessed in macrophage-like cells and animals. It was found that RNA polygons without extension at the vertexes were immune inert. However, when single-stranded RNA with a specific sequence was extended from the vertexes of RNA polygons, strong immune responses were detected. These immunostimulations are sequence specific, because some other extended sequences induced little or no immune response. Additionally, larger-size RNA square induced stronger cytokine secretion. 3D RNA tetrahedron showed stronger immunostimulation than planar RNA triangle. These results suggest that the immunogenicity of RNA nanoparticles is tunable to produce either a minimal immune response that can serve as safe therapeutic vectors, or a strong immune response for cancer immunotherapy or vaccine adjuvants.
Collapse
Affiliation(s)
- Sijin Guo
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH 43210, USA; College of Pharmacy, Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Hui Li
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH 43210, USA; College of Pharmacy, Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Mengshi Ma
- Center for Research on Environmental Disease, College of Medicine, Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Jian Fu
- Center for Research on Environmental Disease, College of Medicine, Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Yizhou Dong
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH 43210, USA; College of Pharmacy, Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH 43210, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA; NCI Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA.
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH 43210, USA; College of Pharmacy, Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH 43210, USA; College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA; NCI Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
11
|
Alibakhshi MA, Halman JR, Wilson J, Aksimentiev A, Afonin KA, Wanunu M. Picomolar Fingerprinting of Nucleic Acid Nanoparticles Using Solid-State Nanopores. ACS NANO 2017; 11:9701-9710. [PMID: 28841287 PMCID: PMC5959297 DOI: 10.1021/acsnano.7b04923] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nucleic acid nanoparticles (NANPs) are an emerging class of programmable structures with tunable shape and function. Their promise as tools for fundamental biophysics studies, molecular sensing, and therapeutic applications necessitates methods for their detection and characterization at the single-particle level. In this work, we study electrophoretic transport of individual ring-shaped and cube-shaped NANPs through solid-state nanopores. In the optimal nanopore size range, the particles must deform to pass through, which considerably increases their residence time within the pore. Such anomalously long residence times permit detection of picomolar amounts of NANPs when nanopore measurements are carried out at a high transmembrane bias. In the case of a NANP mixture, the type of individual particle passing through nanopores can be efficiently determined from analysis of a single electrical pulse. Molecular dynamics simulations provide insight into the mechanical barrier to transport of the NANPs and corroborate the difference in the signal amplitudes observed for the two types of particles. Our study serves as a basis for label-free analysis of soft programmable-shape nanoparticles.
Collapse
Affiliation(s)
| | - Justin R. Halman
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - James Wilson
- Department of Physics, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801, United States
| | - Kirill A. Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
- The Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Meni Wanunu
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| |
Collapse
|
12
|
Jasinski D, Haque F, Binzel DW, Guo P. Advancement of the Emerging Field of RNA Nanotechnology. ACS NANO 2017; 11:1142-1164. [PMID: 28045501 PMCID: PMC5333189 DOI: 10.1021/acsnano.6b05737] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 01/03/2017] [Indexed: 05/14/2023]
Abstract
The field of RNA nanotechnology has advanced rapidly during the past decade. A variety of programmable RNA nanoparticles with defined shape, size, and stoichiometry have been developed for diverse applications in nanobiotechnology. The rising popularity of RNA nanoparticles is due to a number of factors: (1) removing the concern of RNA degradation in vitro and in vivo by introducing chemical modification into nucleotides without significant alteration of the RNA property in folding and self-assembly; (2) confirming the concept that RNA displays very high thermodynamic stability and is suitable for in vivo trafficking and other applications; (3) obtaining the knowledge to tune the immunogenic properties of synthetic RNA constructs for in vivo applications; (4) increased understanding of the 4D structure and intermolecular interaction of RNA molecules; (5) developing methods to control shape, size, and stoichiometry of RNA nanoparticles; (6) increasing knowledge of regulation and processing functions of RNA in cells; (7) decreasing cost of RNA production by biological and chemical synthesis; and (8) proving the concept that RNA is a safe and specific therapeutic modality for cancer and other diseases with little or no accumulation in vital organs. Other applications of RNA nanotechnology, such as adapting them to construct 2D, 3D, and 4D structures for use in tissue engineering, biosensing, resistive biomemory, and potential computer logic gate modules, have stimulated the interest of the scientific community. This review aims to outline the current state of the art of RNA nanoparticles as programmable smart complexes and offers perspectives on the promising avenues of research in this fast-growing field.
Collapse
Affiliation(s)
| | | | - Daniel W Binzel
- College of Pharmacy, Division
of Pharmaceutics and Pharmaceutical Chemistry; College of Medicine,
Department of Physiology & Cell Biology; and Dorothy M. Davis
Heart and Lung Research Institute, The Ohio
State University, Columbus, Ohio 43210, United States
| | - Peixuan Guo
- College of Pharmacy, Division
of Pharmaceutics and Pharmaceutical Chemistry; College of Medicine,
Department of Physiology & Cell Biology; and Dorothy M. Davis
Heart and Lung Research Institute, The Ohio
State University, Columbus, Ohio 43210, United States
| |
Collapse
|
13
|
Halman JR, Satterwhite E, Roark B, Chandler M, Viard M, Ivanina A, Bindewald E, Kasprzak WK, Panigaj M, Bui MN, Lu JS, Miller J, Khisamutdinov EF, Shapiro BA, Dobrovolskaia MA, Afonin KA. Functionally-interdependent shape-switching nanoparticles with controllable properties. Nucleic Acids Res 2017; 45:2210-2220. [PMID: 28108656 PMCID: PMC5389727 DOI: 10.1093/nar/gkx008] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 12/18/2022] Open
Abstract
We introduce a new concept that utilizes cognate nucleic acid nanoparticles which are fully complementary and functionally-interdependent to each other. In the described approach, the physical interaction between sets of designed nanoparticles initiates a rapid isothermal shape change which triggers the activation of multiple functionalities and biological pathways including transcription, energy transfer, functional aptamers and RNA interference. The individual nanoparticles are not active and have controllable kinetics of re-association and fine-tunable chemical and thermodynamic stabilities. Computational algorithms were developed to accurately predict melting temperatures of nanoparticles of various compositions and trace the process of their re-association in silico. Additionally, tunable immunostimulatory properties of described nanoparticles suggest that the particles that do not induce pro-inflammatory cytokines and high levels of interferons can be used as scaffolds to carry therapeutic oligonucleotides, while particles with strong interferon and mild pro-inflammatory cytokine induction may qualify as vaccine adjuvants. The presented concept provides a simple, cost-effective and straightforward model for the development of combinatorial regulation of biological processes in nucleic acid nanotechnology.
Collapse
Affiliation(s)
- Justin R. Halman
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Emily Satterwhite
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Brandon Roark
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Morgan Chandler
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Mathias Viard
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
- Basic Science Program, Leidos Biomedical Research, Inc., RNA Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Anna Ivanina
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Eckart Bindewald
- Basic Science Program, Leidos Biomedical Research, Inc., RNA Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Wojciech K. Kasprzak
- Basic Science Program, Leidos Biomedical Research, Inc., RNA Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Martin Panigaj
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Safarik University in Kosice, Kosice, 041 54, Slovak Republic
| | - My N. Bui
- Department of Chemistry, Ball State University, Muncie, IN 47306, USA
| | - Jacob S. Lu
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Johann Miller
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | | | - Bruce A. Shapiro
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Marina A. Dobrovolskaia
- Nanotechnology Characterization Lab, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Kirill A. Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
- The Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| |
Collapse
|
14
|
Stewart JM, Viard M, Subramanian HKK, Roark BK, Afonin KA, Franco E. Programmable RNA microstructures for coordinated delivery of siRNAs. NANOSCALE 2016; 8:17542-17550. [PMID: 27714127 PMCID: PMC5510167 DOI: 10.1039/c6nr05085a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
RNA is a natural multifunctional polymer, and is an essential component in both complex pathways and structures within the cellular environment. For this reason, artificial self-assembling RNA nanostructures are emerging as a powerful tool with broad applications in drug delivery and metabolic pathway regulation. To date, coordinated delivery of functional molecules via programmable RNA assemblies has been primarily done using nanosize RNA scaffolds. However, larger scaffolds could expand existing capabilities for spatial arrangement of ligands, and enable the controlled delivery of highly concentrated molecular loads. Here, we investigate whether micron-size RNA scaffolds can be assembled and further functionalized with different cargos (e.g. various siRNAs and fluorescent tags) for their synchronized delivery to diseased cells. Since known design approaches to build large RNA scaffolds are still underdeveloped, we apply a tiling method widely used in DNA nanotechnology. DNA tiles have been extensively used to build a variety of scalable and modular structures that are easily decorated with other ligands. Here, we adapt a double crossover (DX) DNA tile motif to design de novo DX RNA tiles that assemble and form lattices via programmed sticky end interactions. We optimize assembly protocols to guarantee high yield of RNA lattices. The resulting constructs are robust and modular with respect to the presence of distinct siRNAs and fluorophores. RNA tiles and lattices are successfully transfected in either human breast cancer or prostate cancer cells, where they efficiently knockdown the expression of target genes. Blood serum stability assays indicate that RNA lattices are more resilient to nuclease degradation when compared to individual tiles, thus making them better suited for therapeutic purposes. Overall, because of its design simplicity, we anticipate that this approach will be utilized for a wide range of applications in therapeutic RNA nanotechnology.
Collapse
Affiliation(s)
- Jaimie Marie Stewart
- Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Mathias Viard
- Basic Science Program, Leidos Biomedical Research, Inc., Gene Regulation and Chromosome Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Hari K K Subramanian
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA 92521, USA.
| | - Brandon K Roark
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA. and The Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Kirill A Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA. and The Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Elisa Franco
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
15
|
Zandi K, Butler G, Kharma N. An Adaptive Defect Weighted Sampling Algorithm to Design Pseudoknotted RNA Secondary Structures. Front Genet 2016; 7:129. [PMID: 27499762 PMCID: PMC4956659 DOI: 10.3389/fgene.2016.00129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 07/06/2016] [Indexed: 01/18/2023] Open
Abstract
Computational design of RNA sequences that fold into targeted secondary structures has many applications in biomedicine, nanotechnology and synthetic biology. An RNA molecule is made of different types of secondary structure elements and an important RNA element named pseudoknot plays a key role in stabilizing the functional form of the molecule. However, due to the computational complexities associated with characterizing pseudoknotted RNA structures, most of the existing RNA sequence designer algorithms generally ignore this important structural element and therefore limit their applications. In this paper we present a new algorithm to design RNA sequences for pseudoknotted secondary structures. We use NUPACK as the folding algorithm to compute the equilibrium characteristics of the pseudoknotted RNAs, and describe a new adaptive defect weighted sampling algorithm named Enzymer to design low ensemble defect RNA sequences for targeted secondary structures including pseudoknots. We used a biological data set of 201 pseudoknotted structures from the Pseudobase library to benchmark the performance of our algorithm. We compared the quality characteristics of the RNA sequences we designed by Enzymer with the results obtained from the state of the art MODENA and antaRNA. Our results show our method succeeds more frequently than MODENA and antaRNA do, and generates sequences that have lower ensemble defect, lower probability defect and higher thermostability. Finally by using Enzymer and by constraining the design to a naturally occurring and highly conserved Hammerhead motif, we designed 8 sequences for a pseudoknotted cis-acting Hammerhead ribozyme. Enzymer is available for download at https://bitbucket.org/casraz/enzymer.
Collapse
Affiliation(s)
- Kasra Zandi
- Computer Science Department, Concordia UniversityMontreal, QC, Canada
| | - Gregory Butler
- Computer Science Department, Concordia UniversityMontreal, QC, Canada
- Centre for Structural and Functional Genomics, Concordia UniversityMontreal, QC, Canada
| | - Nawwaf Kharma
- Centre for Structural and Functional Genomics, Concordia UniversityMontreal, QC, Canada
- Electrical and Computer Engineering Department, Concordia UniversityMontreal, QC, Canada
| |
Collapse
|
16
|
Afonin KA, Viard M, Tedbury P, Bindewald E, Parlea L, Howington M, Valdman M, Johns-Boehme A, Brainerd C, Freed EO, Shapiro BA. The Use of Minimal RNA Toeholds to Trigger the Activation of Multiple Functionalities. NANO LETTERS 2016; 16:1746-53. [PMID: 26926382 PMCID: PMC6345527 DOI: 10.1021/acs.nanolett.5b04676] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Current work reports the use of single-stranded RNA toeholds of different lengths to promote the reassociation of various RNA-DNA hybrids, which results in activation of multiple split functionalities inside human cells. The process of reassociation is analyzed and followed with a novel computational multistrand secondary structure prediction algorithm and various experiments. All of our previously designed RNA/DNA nanoparticles employed single-stranded DNA toeholds to initiate reassociation. The use of RNA toeholds is advantageous because of the simpler design rules, the shorter toeholds, and the smaller size of the resulting nanoparticles (by up to 120 nucleotides per particle) compared to the same hybrid nanoparticles with single-stranded DNA toeholds. Moreover, the cotranscriptional assemblies result in higher yields for hybrid nanoparticles with ssRNA toeholds.
Collapse
Affiliation(s)
- Kirill A. Afonin
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, United States
| | - Mathias Viard
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Philip Tedbury
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Eckart Bindewald
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Lorena Parlea
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Marshall Howington
- Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, United States
| | - Melissa Valdman
- Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, United States
| | - Alizah Johns-Boehme
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Cara Brainerd
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Eric O. Freed
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Bruce A. Shapiro
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| |
Collapse
|
17
|
Bindewald E, Afonin KA, Viard M, Zakrevsky P, Kim T, Shapiro BA. Multistrand Structure Prediction of Nucleic Acid Assemblies and Design of RNA Switches. NANO LETTERS 2016; 16:1726-35. [PMID: 26926528 PMCID: PMC6319913 DOI: 10.1021/acs.nanolett.5b04651] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
RNA is an attractive material for the creation of molecular logic gates that release programmed functionalities only in the presence of specific molecular interaction partners. Here we present HyperFold, a multistrand RNA/DNA structure prediction approach for predicting nucleic acid complexes that can contain pseudoknots. We show that HyperFold also performs competitively compared to other published folding algorithms. We performed a large variety of RNA/DNA hybrid reassociation experiments for different concentrations, DNA toehold lengths, and G+C content and find that the observed tendencies for reassociation correspond well to computational predictions. Importantly, we apply this method to the design and experimental verification of a two-stranded RNA molecular switch that upon binding to a single-stranded RNA toehold disease-marker trigger mRNA changes its conformation releasing an shRNA-like Dicer substrate structure. To demonstrate the concept, connective tissue growth factor (CTGF) mRNA and enhanced green fluorescent protein (eGFP) mRNA were chosen as trigger and target sequences, respectively. In vitro experiments confirm the formation of an RNA switch and demonstrate that the functional unit is being released when the trigger RNA interacts with the switch toehold. The designed RNA switch is shown to be functional in MDA-MB-231 breast cancer cells. Several other switches were also designed and tested. We conclude that this approach has considerable potential because, in principle, it allows the release of an siRNA designed against a gene that differs from the gene that is utilized as a biomarker for a disease state.
Collapse
Affiliation(s)
- Eckart Bindewald
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Kirill A. Afonin
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, United States
| | - Mathias Viard
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Paul Zakrevsky
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Taejin Kim
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Bruce A. Shapiro
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| |
Collapse
|
18
|
Afonin KA, Schultz D, Jaeger L, Gwinn E, Shapiro BA. Silver nanoclusters for RNA nanotechnology: steps towards visualization and tracking of RNA nanoparticle assemblies. Methods Mol Biol 2015; 1297:59-66. [PMID: 25895995 PMCID: PMC6345514 DOI: 10.1007/978-1-4939-2562-9_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The growing interest in designing functionalized, RNA-based nanoparticles (NPs) for applications such as cancer therapeutics requires simple, efficient assembly assays. Common methods for tracking RNA assemblies such as native polyacrylamide gels and atomic force microscopy are often time-intensive and, therefore, undesirable. Here we describe a technique for rapid analysis of RNA NP assembly stages using the formation of fluorescent silver nanoclusters (Ag NCs). This method exploits the single-stranded specificity and sequence dependence of Ag NC formation to produce unique optical readouts for each stage of RNA NP assembly, obtained readily after synthesis.
Collapse
Affiliation(s)
- Kirill A Afonin
- Center for Cancer Research Nanobiology Program, National Cancer Institute, Frederick, MD, 21702, USA
| | | | | | | | | |
Collapse
|
19
|
Abstract
CONSPECTUS: Nanotechnology's central goal involves the direct control of matter at the molecular nanometer scale to build nanofactories, nanomachines, and other devices for potential applications including electronics, alternative fuels, and medicine. In this regard, the nascent use of nucleic acids as a material to coordinate the precise arrangements of specific molecules marked an important milestone in the relatively recent history of nanotechnology. While DNA served as the pioneer building material in nucleic acid nanotechnology, RNA continues to emerge as viable alternative material with its own distinct advantages for nanoconstruction. Several complementary assembly strategies have been used to build a diverse set of RNA nanostructures having unique structural attributes and the ability to self-assemble in a highly programmable and controlled manner. Of the different strategies, the architectonics approach uniquely endeavors to understand integrated structural RNA architectures through the arrangement of their characteristic structural building blocks. Viewed through this lens, it becomes apparent that nature routinely uses thermodynamically stable, recurrent modular motifs from natural RNA molecules to generate unique and more complex programmable structures. With the design principles found in natural structures, a number of synthetic RNAs have been constructed. The synthetic nanostructures constructed to date have provided, in addition to affording essential insights into RNA design, important platforms to characterize and validate the structural self-folding and assembly properties of RNA modules or building blocks. Furthermore, RNA nanoparticles have shown great promise for applications in nanomedicine and RNA-based therapeutics. Nevertheless, the synthetic RNA architectures achieved thus far consist largely of static, rigid particles that are still far from matching the structural and functional complexity of natural responsive structural elements such as the ribosome, large ribozymes, and riboswitches. Thus, the next step in synthetic RNA design will involve new ways to implement these same types of dynamic and responsive architectures into nanostructures functioning as real nanomachines in and outside the cell. RNA nanotechnology will likely garner broader utility and influence with a greater focus on the interplay between thermodynamic and kinetic influences on RNA self-assembly and using natural RNAs as guiding principles.
Collapse
Affiliation(s)
- Wade W. Grabow
- Department
of Chemistry and Biochemistry, Seattle Pacific University, 3307 Third
Avenue West, Seattle, Washington 98119, United States
| | - Luc Jaeger
- Department
of Chemistry and Biochemistry, Bio-Molecular Science and Engineering
Program, University of California, Santa Barbara, California 93106-9510, United States
| |
Collapse
|