Field Of RNA Nanotechnology Research Articles

Therapeutic applications of RNA nanostructures.

RNA-based therapeutics have gained wide public interest in recent years. RNA is a versatile molecule that exists in many forms including mRNA, siRNA, miRNA, ribozymes, and other non-coding RNAs and is primarily applied for gene therapy. RNA is also used as a modular building block to construct RNA nanostructures. The programmable nature of RNA nanostructures enables the generation of simple, modulable, and multi-functional RNA-based therapeutics. Although the therapeutic application of RNA may be limited due to its structural instability, advances in RNA nanotechnology have improved the stability of RNA nanostructures for greater application. Various strategies have been developed to enhance the stability of RNA nanostructures enabling their application in vivo. In this review, we examine the therapeutic applications of RNA nanostructures. Non-immunogenic RNA nanostructures can be rationally designed with functional RNA molecules to modulate gene expression for gene therapy. On the other hand, nucleic acids can be sensed by cellular receptors to elicit an innate immune response, for which certain DNA and RNA motifs can function as adjuvants. Taking advantage of this adjuvant potential, RNA nanostructures can be used for immunotherapy and be designed for cancer vaccines. Thus, we examine the therapeutic application of immunogenic RNA nanostructures for cancer immunotherapy. RNA nanostructures represent promising platforms to design new nanodrugs, gene therapeutics, immunotherapeutic adjuvants, and cancer vaccines. Ongoing research in the field of RNA nanotechnology will continue to empower the development of RNA nanostructure-based therapeutics with high efficacy and limited toxicity.

Translation of the long-term fundamental studies on viral DNA packaging motors into nanotechnology and nanomedicine.

Many years of fundamental studies on viral genome packaging motors have led to fruitful applications. The double-stranded DNA (dsDNA) viruses package their genomes into preformed protein shells via nanomotors including several elegant and meticulous coaxial modules. The motor is geared by the hexameric RNA ring. An open washer displayed as hexametric string of phi29 motor ATPase has been reported. The open washer linked into a filament as a queue with left-handed chirality along the dsDNA chain. It was found that a free 5'- and 3'-dsDNA end is not required for one gp16 dimer and four monomers to assemble into the hexametric washer on dsDNA. The above studies have inspired several applications in nanotechnology and nanomedicine. These applications include: (i) studies on the precision motor channels have led to their application in the single pore sensing; (ii) investigations into the hand-in-hand integration of the hexametric pRNA ring have resulted in the emergence of the new field of RNA nanotechnology; and (iii) the studies on the motor stoichiometry of homologous multi-subunits that subsequently have inspired the discovery of new methods in highly potent drug development. This review focuses on the structure and function of the viral DNA packaging motors and describes how fundamental studies inspired various applications. Given these advantages, more nanotechnological and biomedical applications using bacteriophage motor components are expected.

Tuning the size, shape and structure of RNA nanoparticles for favorable cancer targeting and immunostimulation.

The past decade has shown exponential growth in the field of RNA nanotechnology. The rapid advances of using RNA nanoparticles for biomedical applications, especially targeted cancer therapy, suggest its potential as a new generation of drug. After the first milestone of small molecule drugs and the second milestone of antibody drugs, it was predicted that RNA drugs, either RNA itself or chemicals/ligands that target RNA, will be the third milestone in drug development. Thus, a comprehensive assessment of the current therapeutic RNA nanoparticles is urgently needed to meet the drug evaluation criteria. Specifically, the pharmacological and immunological profiles of RNA nanoparticles need to be systematically studied to provide insights in rational design of RNA-based therapeutics. By virtue of its programmability and biocompatibility, RNA molecules can be designed to construct sophisticated nanoparticles with versatile functions/applications and highly tunable physicochemical properties. This intrinsic characteristic allows the systemic study of the effects of various properties of RNA nanoparticles on their in vivo behaviors such as cancer targeting and immune responses. This review will focus on the recent progress of RNA nanoparticles in cancer targeting, and summarize the effects of common physicochemical properties such as size and shape on the RNA nanoparticles' biodistribution and immunostimulation profiles. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Diagnostic Tools > in vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

A new generation of drugs from the emerging field of RNA nanotechnology

A new generation of drugs from the emerging field of RNA nanotechnology

Evaluation of Thermal Stability of RNA Nanoparticles by Temperature Gradient Gel Electrophoresis (TGGE) in Native Condition.

Temperature gradient gel electrophoresis (TGGE) is a powerful tool used to analyze the thermal stabilities of nucleic acids. While TGGE is a decades-old technique, it has recently gained favor in the field of RNA nanotechnology, notably in assessing the thermal stabilities of RNA nanoparticles (NPs). With TGGE, an electrical current and a linear temperature gradient are applied simultaneously to NP-loaded polyacrylamide gel, separating the negatively charged NPs based on their thermal behavior (a more stable RNA complex will remain intact through higher temperature ranges). The linear temperature gradient can be set either perpendicular or parallel to the electrical current, as either will make the NPs undergo a transition from native to denatured conformations. Often, the melting transition is influenced by sequence variations, secondary/tertiary structures, concentrations, and external factors such as the presence of a denaturing agent (e.g., urea), the presence of monovalent or divalent metal ions, and the pH of the solvent. In this chapter, we describe the experimental setup and the analysis of the thermal stability of RNA NPs in native conditions using a modified version of a commercially available TGGE system.

Uniqueness, Advantages, Challenges, Solutions, and Perspectives in Therapeutics Applying RNA Nanotechnology

The field of RNA nanotechnology is rapidly emerging. RNA can be manipulated with the simplicity characteristic of DNA to produce nanoparticles with a diversity of quaternary structures by self-assembly. Additionally RNA is tremendously versatile in its function and some RNA molecules display catalytic activities much like proteins. Thus, RNA has the advantage of both worlds. However, the instability of RNA has made many scientists flinch away from RNA nanotechnology. Other concerns that have deterred the progress of RNA therapeutics include the induction of interferons, stimulation of cytokines, and activation of other immune systems, as well as short pharmacokinetic profiles in vivo. This review will provide some solutions and perspectives on the chemical and thermodynamic stability, in vivo half-life and biodistribution, yield and production cost, in vivo toxicity and side effect, specific delivery and targeting, as well as endosomal trapping and escape.

Ultrastable synergistic tetravalent RNA nanoparticles for targeting to cancers

One of the advantages of nanotechnology is the feasibility to construct therapeutic particles carrying multiple therapeutics with defined structure and stoichiometry. The field of RNA nanotechnology is emerging. However, controlled assembly of stable RNA nanoparticles with multiple functionalities which retain their original role is challenging due to refolding after fusion. Herein, we report the construction of thermodynamically stable X-shaped RNA nanoparticles to carry four therapeutic RNA motifs by self-assembly of reengineered small RNA fragments. We proved that each arm of the four helices in the X-motif can harbor one siRNA, ribozyme, or aptamer without affecting the folding of the central pRNA-X core, and each daughter RNA molecule within the nanoparticle folds into their respective authentic structures and retains their biological and structural function independently. Gene silencing effects were progressively enhanced as the number of the siRNA in each pRNA-X nanoparticles gradually increased from one to two, three, and four. More importantly, systemic injection of ligand-containing nanoparticles into the tail-vein of mice revealed that the RNA nanoparticles remained intact and strongly bound to cancers without entering the liver, lung or any other organs or tissues, while remaining in cancer tissue for more than 8 h.