Theranostics: aptamer-assisted carbon nanotubes as MRI contrast and photothermal agent for breast cancer therapy.

Breast cancer is one of the leading causes of death among women globally, making its diagnosis and treatment challenging. The use of nanotechnology for cancer diagnosis and treatment is an emerging area of research. To address this issue, multiwalled carbon nanotubes (MWCNTs) were ligand exchanged with butyric acid (BA) to gain hydrophilic character.

Adaptable Self-Assembly of a PEG Dendrimer-Coiled Coil Conjugate.

Self-assembly of designed molecules has enabled the construction of a variety of functional nanostructures. Specifically, adaptable self-assembly has demonstrated several advantageous features for smart materials. Here, we demonstrate that an α-helical coiled coil conjugated with a dendrimer can adapt to spatial restriction due to the strong steric repulsion between dendrimer chains.

Inhibition of protein-protein interactions using biodegradable depsipeptide nanoassemblies.

Although peptides notoriously have poor intrinsic pharmacokinetic properties, it is well-known that nanostructures with excellent pharmacokinetic properties can be designed. Noticing that peptide inhibitors are generally nonpolar, here, we consolidate the peptide inhibitor targeting intracellular protein-protein interactions (PPIs) as an integral part of biodegradable self-assembled depsipeptide nanostructures (SdPNs). Because the peptide inhibitor has the dual role of PPI inhibition and self-assembly in this design, problems associated with the poor pharmacokinetics of peptides and encapsulation/entrapment processes can be overcome.

Self-Assembled Protein Nanostructures via Irreversible Peptide Assembly.

The quaternary structure of proteins extends the functionality of monomeric proteins. Similarly, self-assembled protein nanostructures (SPrNs) have great potential to improve the functionality and complexity of proteins; however, the difficulty associated with the fabrication of SPrNs is far greater than that associated with the fabrication of self-assembled peptides or polymers and often requires sophisticated computational design. To make the process of SPrN formation simpler and more intuitive, herein, we devise a strategy to adopt an irreversible self-assembled peptide nanostructure (SPeN) process en route to the formation of SPrNs.

Cooperative Assembly of Self-Adjusting α-Helical Coiled Coils along the Length of an mRNA Chain to Form a Thermodynamically Stable Nanotube Carrier.

Although mRNA delivery technology is very promising, problems in safety and transport arise due to the intrinsically low thermodynamic stability of the current mRNA carriers. Considering that mRNAs are filamentous and a nanotube is one of the most thermodynamically stable shapes among nanoassemblies, a nanotube is one of the most stable supramolecular structures that can be assembled with mRNA. Here, we develop a nanotube-shaped filamentous mRNA delivery platform that shows exceptionally high thermodynamic stability.

Modulating the folding and binding of peptides using a stimuli-responsive molecular tweezer.

This study presents the development of a β-hairpin (tryptophan zipper, Trpzip)-based molecular tweezer (MT) that can control the folding and binding of α-helical peptides. When an α-helix isolated from the p53 protein was conjugated with Trpzip in an optimized macrocyclic structure, the folded β-hairpin stabilized the helix conformation through the side chain-to-side chain stapling strategy, which notably enhanced target (hDM2) affinity of the peptide. On the other hand, the helicity and binding affinity were significantly reduced when the hairpin was unfolded by a redox stimulus.

Magnetic control of self-assembly and disassembly in organic materials.

Because organic molecules and materials are generally insensitive or weakly sensitive to magnetic fields, a certain means to enhance their magnetic responsiveness needs to be exploited. Here we show a strategy to amplify the magnetic responsiveness of self-assembled peptide nanostructures by synergistically combining the concepts of perfect α-helix and rod-coil supramolecular building blocks. Firstly, we develop a monomeric, nonpolar, and perfect α-helix (MNP-helix).

Pseudo-Isolated α-Helix Platform for the Recognition of Deep and Narrow Targets.

Although interest in stabilized α-helical peptides as next-generation therapeutics for modulating biomolecular interfaces is increasing, peptides have limited functionality and stability due to their small size. In comparison, α-helical ligands based on proteins can make steric clash with targets due to their large size. Here, we report the design of a monomeric pseudo-isolated α-helix (mPIH) system in which proteins behave as if they are peptides.

In pursuit of next-generation therapeutics: Antimicrobial peptides against superbugs, their sources, mechanism of action, nanotechnology-based delivery, and clinical applications.

Antimicrobial peptides (AMPs) attracted attention as potential source of novel antimicrobials. Multi-drug resistant (MDR) infections have emerged as a global threat to public health in recent years. Furthermore, due to rapid emergence of new diseases, there is pressing need for development of efficient antimicrobials.

Unique behaviour of the α-helix in bending deformation.

The maximum degree of bending that can be tolerated by the rigid rod-like α-helix remains unknown; however, it should be very difficult or even impossible to make α-helices with varying degrees of curvature in folded proteins. As an experimentally tractable model, here we utilize cyclic proteins and peptides to determine the maximum possible bending in the α-helix. We artificially enforced bending in the α-helices by using variously sized macrocycles and compared the structural characteristics of the macrocycles with those of their linear counterparts.

Age and Gender Effects on Genotoxicity in Diesel Exhaust Particles Exposed C57BL/6 Mice.

There is growing evidence that the accumulation of DNA damage induced by fine particulate matter (PM) exposure is an underlying mechanism of pulmonary disease onset and progression. However, there is a lack of experimental evidence on whether common factors (age, gender) affect PM induced genomic damage. Here, we assessed the DNA damage potency of PM using conventional genotoxicity testing in old male and female mice aged 8 and 40 weeks.

Disaggregation of Amyloid-β Plaques by a Local Electric Field Generated by a Vertical Nanowire Electrode Array.

The aggregation and accumulation of amyloid-β (Aβ) peptides is a characteristic pathology for Alzheimer's disease (AD). Although noninvasive therapies involving stimulation by electric field (EF) have been reported, the efficiency of Aβ disaggregation needs to be further improved for this strategy to be used in clinical settings. In this study, we show that an electrode based on a vertical nanowire electrode array (VNEA) is far more superior to a typical flat-type electrode in disaggregating Aβ plaques.

A Three-Dimensional Sensor to Recognize Amyloid-β in Blood Plasma of Patients.

Detecting amyloid beta (Aβ) in unpurified blood to diagnose Alzheimer's disease (AD) is challenging owing to low concentrations of Aβ and the presence of many other substances in the blood. Here, we propose a 3D sensor for AD diagnosis using blood plasma, with pairs of 3D silicon micropillar electrodes with a comprehensive circuit configuration. The sensor is developed with synthesized artificial peptide and impedance analysis based on a maximum signal-to-noise ratio.

A Dodecapeptide Selected by Phage Display as a Potential Theranostic Probe for Colon Cancers.

Aim: Colon cancer is one of the leading causes of cancer-related mortality. However, specific biomarkers for its diagnosis or treatment are not established well.

Methods: We developed a colon-cancer specific peptide probe using phage display libraries.

Slow-Motion Self-Assembly: Access to Intermediates with Heterochiral Peptides to Gain Control over Alignment Media Development.

Understanding the intermediates or transition states in organic reactions has made it possible to develop theories and to synthesize important compounds. In contrast to organic reaction intermediates and even protein folding intermediates, the intermediates of peptide/protein self-assembly are not very well understood. Here we report that the self-assembly kinetics of linear heterochiral peptides are significantly slower than those of the corresponding homochiral peptides, which enables direct microscopic observation of assembly intermediates.

Self-Assembling Peptides and Their Application in the Treatment of Diseases.

Self-assembling peptides are biomedical materials with unique structures that are formed in response to various environmental conditions. Governed by their physicochemical characteristics, the peptides can form a variety of structures with greater reactivity than conventional non-biological materials. The structural divergence of self-assembling peptides allows for various functional possibilities; when assembled, they can be used as scaffolds for cell and tissue regeneration, and vehicles for drug delivery, conferring controlled release, stability, and targeting, and avoiding side effects of drugs.

A CMOS VEGF Sensor for Cancer Diagnosis Using a Peptide Aptamer-Based Functionalized Microneedle.

This paper presents the first CMOS Vascular Endothelial Growth Factor (VEGF) sensor for cancer diagnosis directly from human blood. The sensor incorporates a peptide aptamer-based microneedle that allows the detection of electrochemical reactions with VEGF. This results in a capacitance change between the microneedles and then reads out by a two-step capacitance-to-digital converter (CDC).

Investigation of the Hydration State of Self-Assembled Peptide Nanostructures with Advanced Electron Paramagnetic Resonance Spectroscopy.

Probing the intermolecular interactions and local environments of self-assembled peptide nanostructures (SPNs) is crucial for a better understanding of the underlying molecular details of self-assembling phenomena. In particular, investigation of the hydration state is important to understand the nanoscale structural and functional characteristics of SPNs. In this report, we examined the local hydration environments of SPNs in detail to understand the driving force of the discrete geometric structural self-assembling phenomena for peptide nanostructures.

Real-Time Detection of Markers in Blood.

The real-time selective detection of disease-related markers in blood using biosensors has great potential for use in the early diagnosis of diseases and infections. However, this potential has not been realized thus far due to difficulties in interfacing the sensor with blood and achieving transparent circuits that are essential for detecting of target markers (e.g.

Synthesis and purification of self-assembling peptide-oligonucleotide conjugates by solid-phase peptide fragment condensation.

Peptide-oligonucleotide conjugates (POCs) are interesting molecules as they covalently combine 2 of the most important biomacromolecules. Sometimes, the synthesis of POCs involves unexpected difficulties; however, POCs with self-assembling propensity are even harder to synthesize and purify. Here, we show that solid-phase peptide fragment condensation combined with thiol-maleimide or copper-catalyzed azide-alkyne cycloaddition click chemistries is useful for the syntheses of self-assembling POCs.

Fabrication of Multicomponent Multivesicular Peptidoliposomes and Their Directed Cytoplasmic Delivery.

A novel self-assembly strategy for the formation of multicomponent and multicompartment vesicles via the hierarchical assembly of the cyclic peptide and lipid building blocks is reported. The primary driving force underlying the formation of dual-component (i.e.

Inhibition of Multimolecular RNA-Protein Interactions Using Multitarget-Directed Nanohybrid System.

Multitarget-directed ligands (MTDLs) are hybrid ligands obtained by covalently linking active pharmacophores that can act on different targets. We envision that the concept of MTDLs can also be applied to supramolecular bioinorganic nanohybrid systems. Here, we report the inhibition of multimolecular RNA-protein complexes using multitarget-directed peptide-carbon nanotube hybrids (SPCHs).

pH-Dependent In-Cell Self-Assembly of Peptide Inhibitors Increases the Anti-Prion Activity While Decreasing the Cytotoxicity.

The first step in the conventional approach to self-assembled biomaterials is to develop well-defined nanostructures in vitro, which is followed by disruption of the preformed nanostructures at the inside of the cell to achieve bioactivity. Here, we propose an inverse strategy to develop in-cell gain-of-function self-assembled nanostructures. In this approach, the supramolecular building blocks exist in a unimolecular/unordered state in vitro or at the outside of the cell and assemble into well-defined nanostructures after cell internalization.