Phosphofructokinase relocalizes into subcellular compartments with liquid-like properties in vivo.

Although much is known about the biochemical regulation of glycolytic enzymes, less is understood about how they are organized inside cells. We systematically examine the dynamic subcellular localization of glycolytic protein phosphofructokinase-1/PFK-1.1 in Caenorhabditis elegans.

Effect of TiO2 nanoparticles on the hydrogen sorption characteristics of magnesium hydride.

The present paper explores the enhancement in hydrogen sorption behavior of MgH2 with TiO2 nanoparticles. The catalytic effect of TiO2 nanoparticles with different sizes (7, 25, 50, 100 and 250 nm) were used for improving the sorption characteristics of MgH2. The MgH2 catalyzed with 50 nm of TiO2 exhibited the optimum catalytic effect for hydrogen sorption behavior.

Osteochondral interface regeneration of the rabbit knee with macroscopic gradients of bioactive signals.

To date, most interfacial tissue engineering approaches have used stratified designs, in which there are two or more discrete layers comprising the interface. Continuously graded interfacial designs, where there is no discrete transition from one tissue type to another, are gaining attention as an alternative to stratified designs. Given that osteochondral regeneration holds the potential to enhance cartilage regeneration by leveraging the healing capacity of the underlying bone, we endeavored to introduce a continuously-graded approach to osteochondral regeneration.

Biomimetic method for combining the nucleus pulposus and annulus fibrosus for intervertebral disc tissue engineering.

Tissue engineering strategies for the intervertebral disc (IVD) have traditionally focused either on the annulus fibrosus (AF) or the nucleus pulposus (NP) in isolation, or have simply compared AF cells and NP cells in identical culture conditions. Recently, others in the field have become aware of the advantage of combining the AF and NP into a more comprehensive strategy to address IVD tissue engineering, and have introduced biomimetic approaches to either AF or NP tissue engineering. Here, we introduced a new method for developing a biomimetic, cell-seeded IVD by electrospinning circumferentially-orientated polycaprolactone fibres (AF analogue), seeding them with cells (porcine chondrocytes) and then gelling a cell-agarose solution in the centre (NP analogue).

Chondrogenic differentiation of neonatal human dermal fibroblasts encapsulated in alginate beads with hydrostatic compression under hypoxic conditions in the presence of bone morphogenetic protein-2.

In the present work, neonatal human dermal fibroblasts (nHDFs) were evaluated as a potential cell source for intervertebral disc repair. Chondrogenic differentiation of nHDFs was studied in the presence or absence of hydrostatic compression under normal and hypoxic conditions. In addition, the potentially synergistic effects of mechanical stimulation and bone morphogenetic protein (BMP)-2 on the chondrogenic differentiation of nHDFs were assessed.

Reduction of diffusion barriers in isolated rat islets improves survival, but not insulin secretion or transplantation outcome.

For people with type 1 diabetes and severe hypoglycemic unawareness, islet transplants offer hope for improving the quality of life. However, islet cell death occurs quickly during or after transplantation, requiring large quantities of islets per transplant. The purpose of this study was to determine whether poor function demonstrated in large islets was a result of diffusion barriers and if removing those barriers could improve function and transplantation outcomes.

Osteochondral interface tissue engineering using macroscopic gradients of bioactive signals.

Continuous gradients exist at osteochondral interfaces, which may be engineered by applying spatially patterned gradients of biological cues. In the present study, a protein-loaded microsphere-based scaffold fabrication strategy was applied to achieve spatially and temporally controlled delivery of bioactive signals in three-dimensional (3D) tissue engineering scaffolds. Bone morphogenetic protein-2 and transforming growth factor-beta(1)-loaded poly(D,L-lactic-co-glycolic acid) microspheres were utilized with a gradient scaffold fabrication technology to produce microsphere-based scaffolds containing opposing gradients of these signals.

Three-dimensional macroscopic scaffolds with a gradient in stiffness for functional regeneration of interfacial tissues.

A novel approach has been demonstrated to construct biocompatible, macroporous 3-D tissue engineering scaffolds containing a continuous macroscopic gradient in composition that yields a stiffness gradient along the axis of the scaffold. Polymeric microspheres, made of poly(D,L-lactic-co-glycolic acid) (PLGA), and composite microspheres encapsulating a higher stiffness nano-phase material (PLGA encapsulating CaCO(3) or TiO(2) nanoparticles) were used for the construction of microsphere-based scaffolds. Using controlled infusion of polymeric and composite microspheres, gradient scaffolds displaying an anisotropic macroscopic distribution of CaCO(3)/TiO(2) were fabricated via an ethanol sintering technique.

Microsphere-based scaffolds for cartilage tissue engineering: using subcritical CO(2) as a sintering agent.

Shape-specific, macroporous tissue engineering scaffolds were fabricated and homogeneously seeded with cells in a single step. This method brings together CO(2) polymer processing and microparticle-based scaffolds in a manner that allows each to solve the key limitation of the other. Specifically, microparticle-based scaffolds have suffered from the limitation that conventional microsphere sintering methods (e.

Signalling strategies for osteogenic differentiation of human umbilical cord mesenchymal stromal cells for 3D bone tissue engineering.

Human umbilical cord mesenchymal stromal cells (hUCMSCs) have recently shown the capacity to differentiate into multiple cell lineages in all three embryonic germ layers. The osteogenic differentiation of hUCMSCs in monolayer culture has been reported, while the differentiation in three-dimensional biomaterials has not yet been reported for tissue-engineering applications. Thus, the aim of this study was to evaluate the feasibility of using hUCMSCs for bone tissue engineering.

Strategies and applications for incorporating physical and chemical signal gradients in tissue engineering.

From embryonic development to wound repair, concentration gradients of bioactive signaling molecules guide tissue formation and regeneration. Moreover, gradients in cellular and extracellular architecture as well as in mechanical properties are readily apparent in native tissues. Perhaps tissue engineers can take a cue from nature in attempting to regenerate tissues by incorporating gradients into engineering design strategies.

Microsphere-based seamless scaffolds containing macroscopic gradients of encapsulated factors for tissue engineering.

Spatial and temporal control of bioactive signals in three-dimensional (3D) tissue engineering scaffolds is greatly desired. Coupled together, these attributes may mimic and maintain complex signal patterns, such as those observed during axonal regeneration or neovascularization. Seamless polymer constructs may provide a route to achieve spatial control of signal distribution.