An Amperometric Glucose Sensor Integrated into an Insulin Delivery Cannula: In Vitro and In Vivo Evaluation.

Background: Labeling prohibits delivery of insulin at the site of subcutaneous continuous glucose monitoring (CGM). Integration of the sensing and insulin delivery functions into a single device would likely increase the usage of CGM in persons with type 1 diabetes.

Methods: To understand the nature of such interference, we measured glucose at the site of bolus insulin delivery in swine using a flexible electrode strip that was laminated to the outer wall of an insulin delivery cannula.

Amyloid Precursor Proteins Are Dynamically Trafficked and Processed during Neuronal Development.

Proteolytic processing of the Amyloid Precursor Protein (APP) produces beta-amyloid (Aβ) peptide fragments that accumulate in Alzheimer's Disease (AD), but APP may also regulate multiple aspects of neuronal development, albeit via mechanisms that are not well understood. APP is a member of a family of transmembrane glycoproteins expressed by all higher organisms, including two mammalian orthologs (APLP1 and APLP2) that have complicated investigations into the specific activities of APP. By comparison, insects express only a single APP-related protein (APP-Like, or APPL) that contains the same protein interaction domains identified in APP.

Fabrication of a Flexible Amperometric Glucose Sensor Using Additive Processes.

This study details the use of printing and other additive processes to fabricate a novel amperometric glucose sensor. The sensor was fabricated using a Au coated 12.7 μm thick polyimide substrate as a starting material, where micro-contact printing, electrochemical plating, chloridization, electrohydrodynamic jet (e-jet) printing, and spin coating were used to pattern, deposit, chloridize, print, and coat functional materials, respectively.

Can glucose be monitored accurately at the site of subcutaneous insulin delivery?

Because insulin promotes glucose uptake into adipocytes, it has been assumed that during measurement of glucose at the site of insulin delivery, the local glucose level would be much lower than systemic glucose. However, recent investigations challenge this notion. What explanations could account for a reduced local effect of insulin in the subcutaneous space? One explanation is that, in humans, the effect of insulin on adipocytes appears to be small.

High rate shear strain of three-dimensional neural cell cultures: a new in vitro traumatic brain injury model.

The fidelity of cell culture simulations of traumatic brain injury (TBI) that yield tolerance and mechanistic information relies on both the cellular models and mechanical insult parameters. We have designed and characterized an electro-mechanical cell shearing device in order to produce a controlled high strain rate injury (up to 0.50 strain, 30 s(-1) strain rate) that deforms three-dimensional (3-D) neural cultures (neurons or astrocytes in an extracellular matrix scaffold).

Susceptibility of hippocampal neurons to mechanically induced injury.

Experimental models of traumatic cortical brain injury in rodents reveal that specific regions of the hippocampus (e.g., CA3 and hilar subfields) are severely injured despite their distance from the initial insult.

Mechanical stretch to neurons results in a strain rate and magnitude-dependent increase in plasma membrane permeability.

The mechanism by which mechanical impact to brain tissue is transduced to neuronal impairment remains poorly understood. Using an in vitro model of neuronal stretch, we found that mechanical stretch of neurons resulted in a transient plasma membrane permeability increase. Primary cortical neurons, seeded on silicone substrates, were subjected to a defined rate and magnitude strain pulse by stretching the substrates over a fixed cylindrical form.