Pentapartite fractionation of particles in oral fluids by differential centrifugation.

Oral fluids (OFs) contain small extracellular vesicles (sEVs or exosomes) that carry disease-associated diagnostic molecules. However, cells generate extracellular vesicles (EVs) other than sEVs, so the EV population is quite heterogeneous. Furthermore, molecules not packaged in EVs can also serve as diagnostic markers.

Subtypes of tumour cell-derived small extracellular vesicles having differently externalized phosphatidylserine.

Phosphatidylserine (PS) has skewed distributions in the plasma membrane and is preferentially located in the inner leaflet of normal cells. Tumour cells, however, expose PS at the outer leaflet of cell surfaces, thereby potentially modulating the bio-signalling of cells. Interestingly, exosomes - or, more properly, small extracellular vesicles (sEVs) - which are secreted from tumour cells, are enriched with externalized PS, have been proposed as being involved in the progression of cancers, and could be used as a marker for tumour diagnostics.

Host Cell Prediction of Exosomes Using Morphological Features on Solid Surfaces Analyzed by Machine Learning.

Exosomes are extracellular nanovesicles released from any cells and found in any body fluid. Because exosomes exhibit information of their host cells (secreting cells), their analysis is expected to be a powerful tool for early diagnosis of cancers. To predict the host cells, we extracted multidimensional feature data about size, shape, and deformation of exosomes immobilized on solid surfaces by atomic force microscopy (AFM).

Immobilization of a carbon nanomaterial-based localized drug-release system using a bispecific material-binding peptide.

Introduction: Inorganic materials are widely used in medical devices, such as artificial hearts, vessels, and joints, in stents, and as nanocarriers for drug-delivery systems. Carbon nanomaterials are of particular interest due to their biological inertness and their capability to accommodate molecules. Several attempts have been proposed, in which carbon nanomaterials are used as nanocarriers for the systemic delivery of drugs.

Preferential capture of EpCAM-expressing extracellular vesicles on solid surfaces coated with an aptamer-conjugated zwitterionic polymer.

Extracellular vesicles (EVs) collectively represent small vesicles that are secreted from cells and carry biomolecules (e.g., miRNA, lncRNA, mRNA, proteins, lipids, metabolites, etc.

Bridging Adhesion of a Protein onto an Inorganic Surface Using Self-Assembled Dual-Functionalized Spheres.

For the bridging adhesion of different classes of materials in their intact functional states, the adhesion of biomolecules onto inorganic surfaces is a necessity. A new molecular design strategy for bridging adhesion was demonstrated by the introduction of two independent recognition groups on the periphery of spherical complexes self-assembled from metal ions (M) and bidentate ligands (L). These dual-functionalized M12L24 spheres were quantitatively synthesized in one step from two ligands, bearing either a biotin for streptavidin recognition or a titania-binding aptamer, and Pd(II) ions.

Not nanocarbon but dispersant induced abnormality in lysosome in macrophages in vivo.

The properties of nanocarbons change from hydrophobic to hydrophilic as a result of coating them with dispersants, typically phospholipid polyethylene glycols, for biological studies. It has been shown that the dispersants remain attached to the nanocarbons when they are injected in mice and influence the nanocarbons' biodistribution in vivo. We show in this report that the effects of dispersants also appear at the subcellular level in vivo.

Ultrastructural localization of intravenously injected carbon nanohorns in tumor.

Nanocarbons have many potential medical applications. Drug delivery, diagnostic imaging, and photohyperthermia therapy, especially in the treatment of tumors, have attracted interest. For the further advancement of these application studies, the microscopic localization of nanocarbons in tumor tissues and cells is a prerequisite.

A tumor-environment-responsive nanocarrier that evolves its surface properties upon sensing matrix metalloproteinase-2 and initiates agglomeration to enhance T₂ relaxivity for magnetic resonance imaging.

We designed and synthesized a modified ferritin as a tumor-environment-responsive nanocarrier. We found that this nanocarrier could evolve its surface properties upon sensing a tumor-associated protease, matrix metalloproteinase-2 (MMP-2), which initiated agglomeration, resulting in the enhancement of T(2) relaxivity for magnetic resonance imaging (MRI). The designed ferritin contained a triad of modifiers composed of (i) a "sensing" segment (substrate peptide of MMP-2), (ii) "hydrophobic" segments and (iii) a "hydrophilic" segment of polyethylene glycol (PEG).

Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect.

A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified.

Peptide nanofibers modified with a protein by using designed anchor molecules bearing hydrophobic and functional moieties.

Self-assembly of peptides and proteins is a key feature of biological functions. Short amphiphilic peptides designed with a beta-sheet structure can form sophisticated nanofiber structures, and the fibers are available as nanomaterials for arranging biomolecules. Peptide FI (H-PKFKIIEFEP-OH) self-assembles into nanofibers with a coiled fine structure, as reported in our previous work.

Prevention of carbon nanohorn agglomeration using a conjugate composed of comb-shaped polyethylene glycol and a peptide aptamer.

Assured dispersibility is a prerequisite for clinical application of nanomaterials. Carbon nanomaterials have hydrophobic surfaces and thus readily agglomerate under aqueous conditions. Various conjugates composed of a carbon surface-binding moiety and polyethylene glycol (PEG) have been examined as dispersants for carbon nanomaterials.

Biodistribution and ultrastructural localization of single-walled carbon nanohorns determined in vivo with embedded Gd2O3 labels.

Single-walled carbon nanohorns (SWNHs) are single-graphene tubules that have shown high potential for drug delivery systems. In drug delivery, it is essential to quantitatively determine biodistribution and ultrastructural localization. However, to date, these determinations have not been successfully achieved.

Dispersion of cisplatin-loaded carbon nanohorns with a conjugate comprised of an artificial peptide aptamer and polyethylene glycol.

Hydrophobic single-wall carbon nanohorns (SWNHs) were dispersed in aqueous media by noncovalently modifying their surfaces with conjugate molecules comprised of polyethylene glycol (PEG) and a peptide aptamer (NHBP-1) that specifically bind to the surfaces of the SWNHs. The conjugates were synthesized by coupling PEG (average molecular weights of 20,000 and 5000) to the N-terminus of NHBP-1 to produce 20PEG-NHBP and 5PEG-NHBP, respectively. Oxidized SWNHs (oxSWNHs) mixed with 20PEG-NHBP or 5PEG-NHBP were well dispersed in water and passed through a gel filtration column, whereas the oxSWNHs treated with PEG stuck to the top of the column.

Design of peptides that form amyloid-like fibrils capturing amyloid beta1-42 peptides.

Amyloid beta-peptide (Abeta) plays a critical role in Alzheimer's disease (AD). The monomeric state of Abeta can self-assemble into oligomers, protofibrils, and amyloid fibrils. Since the fibrils and soluble oligomers are believed to be responsible for AD, the construction of molecules capable of capturing these species could prove valuable as a means of detecting these potentially toxic species and of providing information pertinent for designing drugs effective against AD.

Construction of biotinylated peptide nanotubes for arranging proteins.

Three kinds of biotinylated peptides with different linkers between biotin and beta-sheet peptide were designed and synthesized. The transmission electron microscopy revealed that the biotinylated peptides self-assembled to form a tubular structure with external diameter of ca. 60 nm and inner diameter of ca.

Construction of a protein array on amyloid-like fibrils using co-assembly of designed peptides.

Amyloid-like fibrils formed from de novo designed short peptides, made up a nanoscale scaffold on which streptavidin was arranged in a regular spacing, potentially allowing the development into an array technology utilizing bio-nanoconstructs.

Fabrication of nanofibers with uniform morphology by self-assembly of designed peptides.

Fabrication of controlled peptide nanofibers with homogeneous morphology has been demonstrated. Amphiphilic beta-sheet peptides were designed as sequences of Pro-Lys-X(1)-Lys-X(2)-X(2)-Glu-X(1)-Glu-Pro. X(1) and X(2) were hydrophobic residues selected from Phe, Ile, Val, or Tyr.

Complementary nucleobase interaction enhances peptide-peptide recognition and self-replicating catalysis.

The availability of the complementary interaction of nucleobases for influencing the formation of peptide architectures was explored. Nucleobases were incorporated as additional recognition elements in coiled-coil peptides by employing nucleobase amino acids (NBAs), which are artificial L-alpha-amino gamma-nucleobase-butyric acids. The effect of the base-pair interaction on intermolecular recognition between peptides was evaluated through a self-replication reaction.