Nanopit-induced osteoprogenitor cell differentiation: The effect of nanopit depth.

We aimed to assess osteogenesis in osteoprogenitor cells by nanopits and to assess optimal feature depth. Topographies of depth 80, 220 and 333 nm were embossed onto polycaprolactone discs. Bone marrow-derived mesenchymal stromal cells were seeded onto polycaprolactone discs, suspended in media and incubated.

Diffusion tensor imaging of the substantia nigra in Parkinson's disease revisited.

Objective: To analyze diffusion tensor imaging (DTI) data in the substantia nigra (SN) using a more consistent region of interest (ROI) defined by neuromelanin-sensitive MRI in order to assess Parkinson's disease (PD) related changes in diffusion characteristics in the SN.

Methods: T1 -weighted and DTI data were obtained in a cohort of 37 subjects (17 control subjects and 20 subjects with PD). The subjects in the PD group were clinically diagnosed PD patients with an average Unified Parkinsonian Disease Rating Scale (UPDRS)-III score of 23.

Using biomaterials to study stem cell mechanotransduction, growth and differentiation.

Self-renewal and differentiation are two fundamental characteristics of stem cells. Stem cell self-renewal is critical for replenishing the stem cell population, while differentiation is necessary for maintaining tissue homeostasis. Over the last two decades a great deal of effort has been applied to discovering the processes that control these opposing stem cell fates.

Using nanotopography and metabolomics to identify biochemical effectors of multipotency.

It is emerging that mesenchymal stem cell (MSC) metabolic activity may be a key regulator of multipotency. The metabolome represents a "snapshot" of the stem cell phenotype, and therefore metabolic profiling could, through a systems biology approach, offer and highlight critical biochemical pathways for investigation. To date, however, it has remained difficult to undertake unbiased experiments to study MSC multipotency in the absence of strategies to retain multipotency without recourse to soluble factors that can add artifact to experiments.

Nanoscale surfaces for the long-term maintenance of mesenchymal stem cell phenotype and multipotency.

There is currently an unmet need for the supply of autologous, patient-specific stem cells for regenerative therapies in the clinic. Mesenchymal stem cell differentiation can be driven by the material/cell interface suggesting a unique strategy to manipulate stem cells in the absence of complex soluble chemistries or cellular reprogramming. However, so far the derivation and identification of surfaces that allow retention of multipotency of this key regenerative cell type have remained elusive.

Nanotopographical control of stem cell differentiation.

Stem cells have the capacity to differentiate into various lineages, and the ability to reliably direct stem cell fate determination would have tremendous potential for basic research and clinical therapy. Nanotopography provides a useful tool for guiding differentiation, as the features are more durable than surface chemistry and can be modified in size and shape to suit the desired application. In this paper, nanotopography is examined as a means to guide differentiation, and its application is described in the context of different subsets of stem cells, with a particular focus on skeletal (mesenchymal) stem cells.

Interactions with nanoscale topography: adhesion quantification and signal transduction in cells of osteogenic and multipotent lineage.

Polymeric medical devices widely used in orthopedic surgery play key roles in fracture fixation and orthopedic implant design. Topographical modification and surface micro-roughness of these devices regulate cellular adhesion, a process fundamental in the initiation of osteoinduction and osteogenesis. Advances in fabrication techniques have evolved the field of surface modification; in particular, nanotechnology has allowed the development of nanoscale substrates for the investigation into cell-nanofeature interactions.