Validation Framework for Sleep Stage Scoring in Wearable Sleep Trackers and Monitors with Polysomnography Ground Truth.

The rapid growth of point-of-care polysomnographic alternatives has necessitated standardized evaluation and validation frameworks. The current average across participant validation methods may overestimate the agreement between wearable sleep tracker devices and polysomnography (PSG) systems because of the high base rate of sleep during the night and the interindividual difference across the sampling population. This study proposes an evaluation framework to assess the aggregating differences of the sleep architecture features and the chronologically epoch-by-epoch mismatch of the wearable sleep tracker devices and the PSG ground truth. An AASM-based sleep stage categorizing method was proposed to standardize the sleep stages scored by different types of wearable trackers. Sleep features and sleep stage architecture were extracted from the PSG and the wearable device's hypnograms. Therefrom, a localized quantifier index was developed to characterize the local mismatch of sleep scoring. We evaluated different commonly used wearable sleep tracking devices with the data collected from 22 different subjects over 30 nights of 8-h sleeping. The proposed localization quantifiers can characterize the chronologically localized mismatches over the sleeping time. The outperformance of the proposed method over existing evaluation methods was reported. The proposed evaluation method can be utilized for the improvement of the sensor design and scoring algorithm.

A Comparison of Fucoidan Conjugated to Paclitaxel and Curcumin for the Dual Delivery of Cancer Therapeutic Agents.

BACKGROUND: The aim of this study was to develop and compare polymeric micelles of fucoidan, a sulfated polysaccharide, and hydrophobic drugs such as paclitaxel and curcumin. Paclitaxel and curcumin are both known for their medicinal properties, including anticancer efficacy. However, their very low water solubility, absorption and rapid metabolism leads to reduced bioavailability. To redress these problems and enhance anti-cancer therapeutics using fucoidan, polymeric micelles were synthesized from conjugates of fucoidan and hydrophobic drugs. METHODS: The chemical conjugation of fucoidan and hydrophobic drugs has been achieved by utilizing reactive functional groups on the molecules, such as carboxylic groups and hydroxyl groups. RESULTS: The micelles revealed a homogeneous spherical morphology, size, negative surface charge. Fourier transform infrared spectroscopy was used to investigate the physicochemical properties of the polymeric micelles, which form a self-assembled polymeric micelle in aqueous medium. The results of the in vitro release of curcumin and fucoidan showed that their release rates were higher at a pH of 4.5 than at a pH of 7.4. In contrast, the paclitaxel conjugate had a similar release profile at pH of 4.5 and pH of 7.4. CONCLUSION: In the present work, we also found an effective drug delivery system that had the ability to release two types of anticancer drugs, fucoidan and hydrophobic drugs, in the tumour environment.

Investigation of Fucoidan-Oleic Acid Conjugate for Delivery of Curcumin and Paclitaxel.

Nanoparticles for a specific delivery are likely to be designed for cancer therapeutic effectiveness and improvement. In this study, a fucoidan-oleic acid conjugate was prepared and investigated in terms of loading capacity for poorly water-soluble anti-cancer drugs to maximize effectiveness of the treatment. Fucoidan was used as a hydrophilic portion of an amphiphilic structure for improving cancer therapeutic effects. Paclitaxel and curcumin were chosen as other model drugs loaded in the conjugates. The results showed that self-assembled nanoparticles with different sizes and morphologies could be prepared with two different concentrations of oleic acid as hydrophobic portion. Moreover, loading efficiency and release patterns of these drugs were mainly dependent on the hydrophobic interaction between drugs and oleic acid. It was also revealed that fucoidan and curcumin were released higher at pH 4.5 than at the physiological condition (pH 7.4), thus, facilitating the delivery and maximizing effects of the anticancer agents on cancer cells. On the contrary, paclitaxel from fucoidan nanoparticles was released faster at pH 7.4. The exploration of fucoidan-oleic acid conjugate could be considered as promising nanomedicines for cancer therapeutics.