In vivo stem cell tracking with imageable nanoparticles that bind bioorthogonal chemical receptors on the stem cell surface.

It is urgently necessary to develop reliable non-invasive stem cell imaging technology for tracking the in vivo fate of transplanted stem cells in living subjects. Herein, we developed a simple and well controlled stem cell imaging method through a combination of metabolic glycoengineering and bioorthogonal copper-free click chemistry. Firstly, the exogenous chemical receptors containing azide (-N) groups were generated on the surfaces of stem cells through metabolic glycoengineering using metabolic precursor, tetra-acetylated N-azidoacetyl-d-mannosamine(AcManNAz).

Non-invasive stem cell tracking in hindlimb ischemia animal model using bio-orthogonal copper-free click chemistry.

Labeling of stem cells aims to distinguish transplanted cells from host cells, understand in vivo fate of transplanted cells, particularly important in stem cell therapy. Adipose-derived mesenchymal stem cells (ASCs) are considered as an emerging therapeutic option for tissue regeneration, but much remains to be understood regarding the in vivo evidence. In this study, a simple and efficient cell labeling method for labeling and tracking of stem cells was developed based on bio-orthogonal copper-free click chemistry, and it was applied in a mouse hindlimb ischemia model.

ROS-generating TiO2 nanoparticles for non-invasive sonodynamic therapy of cancer.

The non-invasive photodynamic therapy has been limited to treat superficial tumours, primarily ascribed to poor tissue penetration of light as the energy source. Herein, we designed a long-circulating hydrophilized titanium dioxide nanoparticle (HTiO2 NP) that can be activated by ultrasound to generate reactive oxygen species (ROS). When administered systemically to mice, HTiO2 NPs effectively suppressed the growth of superficial tumours after ultrasound treatments.

Bioorthogonal Copper Free Click Chemistry for Labeling and Tracking of Chondrocytes In Vivo.

Establishment of an appropriate cell labeling and tracking method is essential for the development of cell-based therapeutic strategies. Here, we are introducing a new method for cell labeling and tracking by combining metabolic gylcoengineering and bioorthogonal copper-free Click chemistry. First, chondrocytes were treated with tetraacetylated N-azidoacetyl-D-mannosamine (Ac4ManNAz) to generate unnatural azide groups (-N3) on the surface of the cells.

Exosomes from differentiating human skeletal muscle cells trigger myogenesis of stem cells and provide biochemical cues for skeletal muscle regeneration.

Exosomes released from skeletal muscle cells play important roles in myogenesis and muscle development via the transfer of specific signal molecules. In this study, we investigated whether exosomes secreted during myotube differentiation from human skeletal myoblasts (HSkM) could induce a cellular response from human adipose-derived stem cells (HASCs) and enhance muscle regeneration in a muscle laceration mouse model. The exosomes contained various signal molecules including myogenic growth factors related to muscle development, such as insulin-like growth factors (IGFs), hepatocyte growth factor (HGF), fibroblast growth factor-2 (FGF2), and platelet-derived growth factor-AA (PDGF-AA).

Cell labeling and tracking method without distorted signals by phagocytosis of macrophages.

Cell labeling and tracking are important processes in understanding biologic mechanisms and the therapeutic effect of inoculated cells in vivo. Numerous attempts have been made to label and track inoculated cells in vivo; however, these methods have limitations as a result of their biological effects, including secondary phagocytosis of macrophages and genetic modification. Here, we investigated a new cell labeling and tracking strategy based on metabolic glycoengineering and bioorthogonal click chemistry.

Decellularized extracellular matrix derived from porcine adipose tissue as a xenogeneic biomaterial for tissue engineering.

Cells in tissues are surrounded by the extracellular matrix (ECM), a gel-like material of proteins and polysaccharides that are synthesized and secreted by cells. Here we propose that the ECM can be isolated from porcine adipose tissue and holds great promise as a xenogeneic biomaterial for tissue engineering and regenerative medicine. Porcine adipose tissue is easily obtained in large quantities from commonly discarded food waste.

Human collagen isolated from adipose tissue.

Collagen, the most abundant protein in vertebrates, is a useful biomaterial in pharmaceutical and medical industries. So far, most collagen has been extracted from animals and cadavers. Herein, we suggest human adipose tissue, which is routinely abandoned after liposuction, as a plentiful source of human collagen.

Electrochemical endotoxin sensors based on TLR4/MD-2 complexes immobilized on gold electrodes.

Even low concentrations of endotoxins can be life-threatening. As such, continuous effort has been directed toward the development of sensitive and specific endotoxin detection systems. In this paper, we report the design and fabrication of a new electrochemical endotoxin sensor based on a human recombinant toll-like receptor 4 (rhTLR4) and myeloid differentiation-2 (MD-2) complex.