Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

50 Years of Image Analysis

DNA has become one of the most extensively used molecular building blocks for engineering self-assembling materials. DNA origami is a technique that uses hundreds of short DNA oligonucleotides, called staple strands, to fold a long single-stranded DNA, which is called a scaffold strand, into various designer nanoscale architectures. DNA origami has dramatically improved the complexity and scalability of DNA nanostructures. Due to its high degree of customization and spatial addressability, DNA origami provides a versatile platform with which to engineer nanoscale structures and devices that can sense, compute, and actuate. These capabilities open up opportunities for a broad range of applications in chemistry, biology, physics, material science, and computer science that have often required programmed spatial control of molecules and atoms in three-dimensional (3D) space. This review provides a comprehensive survey of recent developments in DNA origami structure, design, assembly, and directed self-assemb...

DNA Origami: Scaffolds for Creating Higher Order Structures

Knowledge of therapeutic targets and early drug candidates is useful for improved drug discovery. In particular, information about target regulators and the patented therapeutic agents facilitates research regarding druggability, systems pharmacology, new trends, molecular landscapes, and the development of drug discovery tools. To complement other databases, we constructed the Therapeutic Target Database (TTD) with expanded information about (i) target-regulating microRNAs and transcription factors, (ii) target-interacting proteins, and (iii) patented agents and their targets (structures and experimental activity values if available), which can be conveniently retrieved and is further enriched with regulatory mechanisms or biochemical classes. We also updated the TTD with the recently released International Classification of Diseases ICD-11 codes and additional sets of successful, clinical trial, and literature-reported targets that emerged since the last update. TTD is accessible at http://bidd.nus.edu.sg/group/ttd/ttd.asp. In case of possible web connectivity issues, two mirror sites of TTD are also constructed (http://db.idrblab.org/ttd/ and http://db.idrblab.net/ttd/).

Therapeutic target database 2020: enriched resource for facilitating research and early development of targeted therapeutics

https://ris.utwente.nl/ws/files/127602657/drug.pdf

Drug delivery systems and materials for wound healing applications.

Development of biosensing platforms plays a key role in research settings for identification of biomarkers and in clinical applications for diagnostics. Biosensors based on nucleic acids have taken many forms, from simple duplex-based constructs to stimuli-responsive nucleic acid nanostructures. In this review, we look at various nucleic acid-based biosensors, the different read-out strategies employed, and their use in chemical and biological sensing. We also look at current developments in DNA nanotechnology-based biosensors and how rational design of such constructs leads to more efficient biosensing platforms.

Rationally Engineered Nucleic Acid Architectures for Biosensing Applications.

Engineering dermal substitutes with electrospun nanofibres have lately been of prime importance for skin tissue regeneration. Simple electrospinning technology served to produce nanofibrous scaffolds morphologically and structurally similar to the extracellular matrix of native tissues. The nanofibrous scaffolds of poly(l-lactic acid)-co-poly(e-caprolactone) (PLACL) and PLACL/gelatin complexes were fabricated by the electrospinning process. These nanofibres were characterized for fibre morphology, membrane porosity, wettability and chemical properties by FTIR analysis to culture human foreskin fibroblasts for skin tissue engineering. The nanofibre diameter was obtained between 282 and 761 nm for PLACL and PLACL/gelatin scaffolds; expressions of amino and carboxyl groups and porosity up to 87% were obtained for these fibres, while they also exhibited improved hydrophilic properties after plasma treatment. The results showed that fibroblasts proliferation, morphology, CMFDA dye expression and secretion of collagen were significantly increased in plasma-treated PLACL/gelatin scaffolds compared to PLACL nanofibrous scaffolds. The obtained results prove that the plasma-treated PLACL/gelatin nanofibrous scaffold is a potential biocomposite material for skin tissue regeneration.

https://iopscience.iop.org/article/10.1088/1748-6041/6/1/015001/pdf

Fabrication of a nanofibrous scaffold with improved bioactivity for culture of human dermal fibroblasts for skin regeneration.

Protective clothing currently used against chemical and biological warfare (CBW) agents use activated charcoal impregnated with metal ions, which serve to physically adsorb nerve and blister agents thereby creating disposal hazards after its usage. Nanotechnology is booming in an unprecedented way in creating its impact in various applications such as in catalysis. Metal oxide nanoparticles (MONPs) such as TiO2 and MgO are currently used as potential catalysts for the decontamination of CBW agents. Various synthetic routes adopted for the preparation of MONPs are highlighted in this review. When compared with conventionally-prepared samples, aerogel-prepared samples are more reactive toward toxic chemicals and their ability to degrade CBW is presented here. TiO2 photocatalysts in the presence of UV light and mixed metal oxides are found to be efficient catalysts when compared with individual oxides. The recent trend of exploiting nanoparticles and the high aspect ratio ceramic oxide nanofibers for use in protective clothing, wipe materials, and textiles has been presented. Some of the issues concerning integration of metal oxides into fabrics for sensors are also reviewed in this article.

An Update on Nanomaterials-Based Textiles for Protection and Decontamination

DNA nanotechnology has progressed from proof-of-concept demonstrations of structural design towards application-oriented research As a natural material with excellent self-assembling properties, DNA is an indomitable choice for various biological applications, including biosensing, cell modulation, bioimaging and drug delivery However, a major impediment to the use of DNA nanostructures in biological applications is their susceptibility to attack by nucleases present in the physiological environment Although several DNA nanostructures show enhanced resistance to nuclease attack compared with duplexes and plasmid DNA, this may be inadequate for practical application Recently, several strategies have been developed to increase the nuclease resistance of DNA nanostructures while retaining their functions, and the stability of various DNA nanostructures has been studied in biological fluids, such as serum, urine and cell lysates This Review discusses the approaches used to modulate nuclease resistance in DNA nanostructures and provides an overview of the techniques employed to evaluate resistance to degradation and quantify stability

/pdf/nuclease-resistance-of-dna-nanostructures-1f22u9pejz.pdf

Arun Richard Chandrasekaran

Papers

Rationally Engineered Nucleic Acid Architectures for Biosensing Applications.

Fabrication of a nanofibrous scaffold with improved bioactivity for culture of human dermal fibroblasts for skin regeneration.

An Update on Nanomaterials-Based Textiles for Protection and Decontamination

Nuclease resistance of DNA nanostructures.

DNA Nanocarriers: Programmed to Deliver