silicon and Diabetes-Mellitus

Diabetic wound healing is highly desirable but remains a great challenge owing to the continuous damage of excess reactive oxygen species (ROS) and degradation of therapeutic peptide drugs by over-expressed matrix metalloproteinase (MMP). Herein, we developed a stimuli-responsive smart dressing for theranostics of diabetic wounds using graphene quantum dots-decorated luminescent porous silicon (GQDs@PSi), which was further loaded with peptide and embedded in chitosan (CS) film. The confinement of GQDs in nanochannels of PSi endowed GQDs@PSi with efficient fluorescence resonance energy transfer (FRET) effect, leading to initial red fluorescence of PSi with complete quench of GQD's blue fluorescence. Furthermore, the decoration of GQDs on PSi surface significantly enhanced the loading capacity for peptide drugs including epidermal growth factor (EGF) and insulin (Ins) which can promote diabetic wounds healing. The peptides coloaded in GQDs@PSi exhibited sustained release behavior and could be protected in presence of MMP owing to size exclusion of PSi's nanochannels. As H

Topics: Bandages; Diabetes Mellitus; Graphite; Humans; Hydrogen Peroxide; Porosity; Precision Medicine; Quantum Dots; Silicon

This paper presents the development of an extremely sensitive and selective acetone sensor prototype which can be used as a platform for non-invasive diabetes detection through exhaled human breath. The miniaturized sensors were produced in high yield with the use of standard microfabrication processes. The sensors were based on a heterostructure composed of MoO

Topics: Acetone; Diabetes Mellitus; Humans; Microscopy, Atomic Force; Molybdenum; Nanopores; Oxides; Photoelectron Spectroscopy; Porosity; Silicon; Surface Properties; Volatile Organic Compounds; X-Ray Diffraction

Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO(3) nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20ppb) with short response (10-15s) and recovery times (35-70s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80-90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.

Topics: Acetone; Biosensing Techniques; Breath Tests; Diabetes Mellitus; Humans; Limit of Detection; Nanoparticles; Oxides; Sensitivity and Specificity; Silicon; Tungsten

Acetone in the human breath is an important marker for noninvasive diagnosis of diabetes. Here, novel chemo-resistive detectors have been developed that allow rapid measurement of ultralow acetone concentrations (down to 20 ppb) with high signal-to-noise ratio in ideal (dry air) and realistic (up to 90% RH) conditions. The detector films consist of (highly sensitive) pure and Si-doped WO(3) nanoparticles (10-13 nm in diameter) made in the gas phase and directly deposited onto interdigitated electrodes. Their sensing properties (selectivity, limit of detection, response, and recovery times) have been investigated as a function of operating temperature (325-500 degrees C), relative humidity (RH), and interfering analyte (ethanol or water vapor) concentration. It was found that Si-doping increases and stabilizes the acetone-selective epsilon-WO(3) phase while increasing its thermal stability and, thus, results in superior sensing performance with an optimum at about 10 mol % Si content. Furthermore, increasing the operation temperature decreased the detector response to water vapor, and above 400 degrees C, it was (or=1800 ppb) can be clearly distinguished by a remarkable gap (40%) in sensor response. As a result, these solid state detectors may offer a portable and cost-effective alternative to more bulky systems for noninvasive diabetes detection by human breath analysis.

Topics: Acetone; Aluminum Oxide; Breath Tests; Diabetes Mellitus; Gold; Humans; Limit of Detection; Silicon; Surface Properties; Tungsten

A unique minimally invasive system for painless blood testing is now being commercialized for measurement of blood glucose concentration by diabetics. The novel component of this system, a consumable microsampling and assay device, consists of a tough, flexible silicon microneedle comparable in cross-section to a human hair integrated with a silicon microcuvette. This microneedle is capable of reliably taking a very small sample of whole blood completely painlessly, unlike sticks with the much larger metal lancet that must be used in all other current systems. The device permits a one-step process that avoids the need to transfer blood from a skin puncture to a test strip, thus minimizing blood required and possible mess. The small hand-held instrument containing the consumable is touched to the skin of the arm or any other part of the body, not necessarily the tip of the finger, and held there for one second. During this time, the microneedle is advanced and then withdrawn under microprocessor control, puncturing the skin and drawing less than 200 nanoliters of blood into the microcuvette, where the assay is performed automatically. The instrument calculates the blood glucose concentration, displays the result, and holds it in memory for recall. The consumable is produced by silicon microelectromechanical systems technology and can be produced in high volume at low unit cost. This technology shows promise of being extended to other analytes and to continuous monitoring.

Topics: Blood Glucose; Blood Specimen Collection; Diabetes Mellitus; Equipment Design; Fingers; Humans; Miniaturization; Monitoring, Physiologic; Needles; Pain; Point-of-Care Systems; Regression Analysis; Reproducibility of Results; Silicon; Skin

Specialized "nutritional insurance" supplementation may reduce the risk of many important complications of long-term corticosteroid treatment. Supplementation with calcium, fluoride, activated vitamin D metabolites, and GTF, should help prevent osteoporosis. GTF, vitamin C, zinc and fluoride might help offset the inhibitory effect of corticosteroids on fibroblast and osteoblast function. Diabetic, hyperlipidemic and protein-losing effects might be compensated with supplementary GTF. Antioxidant nutrients could support humoral immunity and neutrophil function, while complementing the anti-inflammatory actions of corticosteroids. Supplementary magnesium could reduce the risk of nephrocalcinosis and nephrolithiasis.

Topics: Adrenal Cortex Hormones; Amino Acids; Ascorbic Acid; Chromium; Diabetes Mellitus; Double-Blind Method; Fluorides; Food, Fortified; Humans; Hydroxycholecalciferols; Hyperlipidemias; Immunologic Deficiency Syndromes; Nephrocalcinosis; Nicotinic Acids; Nutritional Requirements; Osteoporosis; Selenium; Silicon

Topics: Adult; Aged; Aluminum; Blood Coagulation; Copper; Diabetes Complications; Diabetes Mellitus; Female; Gangrene; Humans; Male; Manganese; Middle Aged; Silicon; Titanium; Trace Elements

Topics: Blood Glucose; Chemical Phenomena; Chemistry; Chromatography, Gas; Diabetes Mellitus; Disaccharides; Ethers; Food Analysis; Humans; Male; Mannitol; Methods; Monosaccharides; Silicon; Solubility; Sorbitol; Time Factors