Designing systems that build themselves is one of the great dreams of nanotechnology researchers, and they are taking great strides towards developing such 'bottom-up' nanotechnology fabrication techniques. Fabrication processes based on DNA might change this: DNA origami have been heralded as a potential breakthrough for the creation of nanoscale devices. Researchers have now developed methods to assemble DNA-functionalized microparticles into a colloidal gel, and to extrude this gel with a 3D printer at centimeter size scales.
There is a significant need for new therapeutic approaches to combat diseases such as cancer and viral infections. Using RNA as a therapeutic modality brings to bear an entirely new approach, which not only allows for the construction of uniform scaffolds for attachment of functional entities, but also permits the use of all the different types of functionalities that are inherent in natural RNAs. New research demonstrates that multifunctional RNA nanoparticles with a nanoring design allow the use of different types of functionalities inherent in natural RNAs.
Gene transcription is tightly regulated by proteins called transcription factors. These transcription factor (TF) proteins are master regulators of transcriptional activity and gene expression. Transcription factors are responsible for transcribing the correct genes and therefore for producing the right quantity of proteins. TF-based gene regulation is a promising approach for many biological applications, however, several limitations hinder the full potential of TFs. To overcome these problems, an international team of researchers has developed an artificial, nanoparticle-based transcription factor, termed NanoScript, which is designed to mimic the structure and function of TFs.
Cytosine (C) modifications such as 5-methylcytosine (mC) and 5-hydroxymethylcytosine (hmC) are important epigenetic markers associated with gene expression and tumorigenesis. However, bisulfite conversion, the gold standard methodology for mC mapping, can not distinguish mC and hmC bases. Recent studies have demonstrated hmC detection via peptide recognizing, enzymes, fluorescence and hmC-specific antibodies - nevertheless, a method for directly discriminating C, mC and hmC bases without labeling, modification and amplification is still missing. New results demonstrate that single base of C, mC and hmC can be discriminated at the latch zone of a nanopore.
DNA is constantly being damaged in our cells by radiation and other random sources. One of the major forms of this damage is called depurination, or the selective loss of A and G bases from the double helix structure. In our cells, there is a system in place to fix depurination. It usually is quite successful at repairing the damage, but can sometimes make mistakes that result in mutations. As a result, depurination is directly linked to a host of diseases, including anemia and cancer. In new work, researchers show that DNA depurination can be detected electrically using solid-state nanopores.
Sequencing technologies have made it cheaper and faster to read the sequence of bases on a strand of DNA. A promising technology to take these advances further is nanopore sequencing. Individual strands of DNA are moved through a nanopore gap not much wider than the DNA itself. As the DNA passes through the nanopore, continuous information is gained about the sequence of individual bases - the A, C, G and Ts that make up DNA. Researchers now have developed a nanopore sequencing technique reaching read lengths of several thousand bases.
One way to eliminate the toxicity issue of synthetic nanomaterials used in nanomedicine is by working with truly biocompatible natural carriers for sensing and drug delivery applications. The emerging field of DNA nanotechnology may provide a solution. In new work, researchers have developed a novel theranostic platform which is made by utilizing a self-assembled DNA nanopyramid as scaffold for incorporation of both detection and therapeutic moieties to combat bacterial infection.
Nanomaterials for nanomedicine and biological applications are often two-component structures - referred to as 'nanoconstructs' -consisting of a 'hard' nanoparticle core and a 'soft' shell of biomolecular ligands. Researchers have now demonstrated a nanoconstruct with enhanced in vitro efficacy. This highly loaded nanoconstruct was taken up by pancreatic cancer cells and fibrosarcoma cells at fast rates. The team found that the increased loading of Apt on AuNS also resulted in an enhanced in vitro response.