Nanobiotechnology

About: Nanobiotechnology is a research topic. Over the lifetime, 796 publications have been published within this topic receiving 46309 citations. The topic is also known as: bionanotechnology & nanobiology.

Toward Single Electron Nanoelectronics Using Self-Assembled DNA Structure

Abstract: DNA based structures offer an adaptable and robust way to develop customized nanostructures for various purposes in bionanotechnology. One main aim in this field is to develop a DNA nanobreadboard for a controllable attachment of nanoparticles or biomolecules to form specific nanoelectronic devices. Here we conjugate three gold nanoparticles on a defined size TX-tile assembly into a linear pattern to form nanometer scale isolated islands that could be utilized in a room temperature single electron transistor. To demonstrate this, conjugated structures were trapped using dielectrophoresis for current–voltage characterization. After trapping only high resistance behavior was observed. However, after extending the islands by chemical growth of gold, several structures exhibited Coulomb blockade behavior from 4.2 K up to room temperature, which gives a good indication that self-assembled DNA structures could be used for nanoelectronic patterning and single electron devices.

Delivering colloidal nanoparticles to mammalian cells: a nano-bio interface perspective

Abstract: Understanding the behavior of multifunctional colloidal nanoparticles capable of biomolecular targeting remains a fascinating challenge in materials science with dramatic implications in view of a possible clinical translation. In several circumstances, assumptions on structure-activity relationships have failed in determining the expected responses of these complex systems in a biological environment. The present Review depicts the most recent advances about colloidal nanoparticles designed for use as tools for cellular nanobiotechnology, in particular, for the preferential transport through different target compartments, including cell membrane, cytoplasm, mitochondria, and nucleus. Besides the conventional entry mechanisms based on crossing the cellular membrane, an insight into modern physical approaches to quantitatively deliver nanomaterials inside cells, such as microinjection and electro-poration, is provided. Recent hypotheses on how the nanoparticle structure and functionalization may affect the interactions at the nano-bio interface, which in turn mediate the nanoparticle internalization routes, are highlighted. In addition, some hurdles when this small interface faces the physiological environment and how this phenomenon can turn into different unexpected responses, are discussed. Finally, possible future developments oriented to synergistically tailor biological and chemical properties of nanoconjugates to improve the control over nanoparticle transport, which could open new scenarios in the field of nanomedicine, are addressed.

Ingenious Design of DNA Concatamers and G-Quadruplex Wires Assisted Assembly of Multibranched DNA Nanoarchitectures for Ultrasensitive Biosensing of miRNA.

Abstract: Facile and efficient assembly of intelligent DNA nano-objects with the ability to exert robust microRNA determination is essential for DNA nanobiotechnology and basic biomedical study. Herein, we present a novel target-triggered DNA assembly pathway for the construction of multibranched DNA nanoarchitectures by the combination of DNA concatamers with G-quadruplex wires. The DNA concatamers acting as the main body structures were assembled by hybridization chain reaction (HCR), while the G-quadruplex wires acting as the branch structures were generated by terminal deoxynucleotidyl transferase (TdT)-promoted polymerization and G-quadruplex units (GUs) based self-assembly. With a copious number of G-quadruplex replicates collected on the electrode surface, the obtained multibranched DNA nanoarchitectures were able to bind with lots of hemin, which further led to a significantly amplified electrochemical sensing signal for ultrasensitive and selective detection of miRNA-21. The detection limit was achieved as low as 0.2 fM with a wide dynamic response ranging from 10 fM to 100 nM, which is much more powerful or at least comparable to most of the reported studies. Furthermore, the electrochemical biosensor offered an excellent specificity, and even the single-base mutation against the perfectly matched target miRNA can be easily distinguished easily. Furthermore, the real biological samples were also desirably analyzed, indicating that the proposed strategy is an ideal platform for the fabrication of versatile DNA nanobiosensors.

Controlled assembly of peptide nanotubes triggered by enzymatic activation of self-immolative dendrimers.

Abstract: Although various building blocks can self-assemble to form ordered structures on the nanoscale, the temporal and spatial control of such processes is key for the technological application of these nanostructures. The ability to precisely control the formation of nanoassemblies by an external signal is highly desirable. The aromatic dipeptide nanotubes [ADNT] represent a unique class of organic nanostructures. These bio-inspired structures are formed by the self-assembly of the core recognition motif of the b-amyloid polypeptide into hollow tubes of remarkable persistence, length and rigidity. Biocompatible and water-soluble ADNT are readily formed under mild conditions from inexpensive starting materials. Furthermore, the ADNTs have remarkable chemical and thermal stability and extraordinary mechanical strength; this makes these nanotubes attractive for various applications. The application of these tubes for the fabrication of metal wires and coaxial nanocables for the organization of platinum nanoparticles, as well as for electrochemical biosensors has been demonstrated. 20] Methodologies were also developed for the horizontal and vertical patterning of aligned ADNT. A limiting factor in the utilization of this system, however, is the ability to temporally control the assembly process. Therefore, we decided to explore the ability of a self-immolative dendritic system to serve as a platform for the controlled assembly of peptide nanotubes. The extremely short length of the peptide building blocks and their ability to self-assemble make these units ideal candidates for controlled assembly applications. Self-immolative dendrimers are a novel class of molecules that can amplify a single cleavage event, which is received at a focal point, into multiple releases of tail groups at the periphery. These dendrimers have been used for the construction of unique dendritic prodrugs that have a specific trigger attached to the focal point, and drug molecules linked to the periphery. Self-immolative dendritic prodrugs that are activated through a single catalytic reaction by a specific enzyme offer significant advantages in the inhibition of tumor growth relative to the monomeric prodrugs, especially if the activating enzyme exists at relatively low levels in the malignant tissue. Here, we explored the potential of a self-immolative dendritic system to serve as a transporter platform for control assembly of the peptide nanostructures. We have recently developed an AB3 self-immolative dendritic system, like 1 that can release three reporter groups upon activation by penicillin G amidase (PGA). The first step of the disassembly is the catalytic cleavage of phenylacetic acid by PGA, followed by the elimination of azaquinone-methide and decarboxylation to release amine intermediate 1a. This amine intermediate further disassembles through triple elimination to release the three drug units (Scheme 1). The disassembly of this molecule after the enzymatic cleavage is based solely on