A Low-Power, Low-Cost Ingestible and Wearable Sensing Platform to Measure Medication Adherence and Physiological Signals.

In this paper, we present a novel Digital Medicines program used for reviewing medication adherence. The program is comprised of an ingestible sensor embedded inside medication and a wearable sensor or patch worn on the skin of the patient. The ingestible sensor activates upon contact with gastric fluids and communicates information about the ingested drug to the patch. Adherence patterns and other physiological markers measured by the system are made available to patients, physicians, and caregivers via mobile and web interfaces. The paper focuses on the wearable sensor hardware and measurement features used to provide a more comprehensive view of the patient's health centered around and contextualized by adherence patterns. This is achieved using efficient, high-performance signal processing algorithms implemented on a low-power platform. Results from bench and clinical testing are presented to demonstrate the performance of adherence, heart rate, step counts, and body angle measurements.

Surface charge of gold nanoparticles mediates mechanism of toxicity.

Recently gold nanoparticles (Au NPs) have shown promising biological and military applications due to their unique electronic and optical properties. However, little is known about their biocompatibility in the event that they come into contact with a biological system. In the present study, we have investigated whether modulating the surface charge of 1.5 nm Au NPs induced changes in cellular morphology, mitochondrial function, mitochondrial membrane potential (MMP), intracellular calcium levels, DNA damage-related gene expression, and of p53 and caspase-3 expression levels after exposure in a human keratinocyte cell line (HaCaT). The evaluation of three different Au NPs (positively charged, neutral, and negatively charged) showed that cell morphology was disrupted by all three NPs and that they demonstrated a dose-dependent toxicity; the charged Au NPs displayed toxicity as low as 10 µg ml(-1) and the neutral at 25 µg ml(-1). Furthermore, there was significant mitochondrial stress (decreases in MMP and intracellular Ca2+ levels) following exposure to the charged Au NPs, but not the neutral Au NPs. In addition to the differences observed in the MMP and Ca2+ levels, up or down regulation of DNA damage related gene expression suggested a differential cell death mechanism based on whether or not the Au NPs were charged or neutral. Additionally, increased nuclear localization of p53 and caspase-3 expression was observed in cells exposed to the charged Au NPs, while the neutral Au NPs caused an increase in both nuclear and cytoplasmic p53 expression. In conclusion, these results indicate that surface charge is a major determinant of how Au NPs impact cellular processes, with the charged NPs inducing cell death through apoptosis and neutral NPs leading to necrosis.