Micro-vibration assisted dual-layer spiral microneedles to rapidly extract dermal interstitial fluid for minimally invasive detection of glucose.

Various hydrogels have been explored to create minimally invasive microneedles (MNs) to extract interstitial fluid (ISF). However, current methods are time-consuming and typically require 10-15 min to extract 3-5 mg of ISF. This study introduces two spiral-shaped swellable MN arrays: one made of gelatin methacryloyl (GelMA) and polyvinyl alcohol (PVA), and the other incorporating a combination of PVA, polyvinylpyrrolidone (PVP), and hyaluronic acid (HA) for fast ISF extraction.

The role of microneedles in the healing of chronic wounds.

Chronic wounds occur for several reasons, such as trauma, accidents, and diseases. Diabetes has been one of the primary causes of non-healing wounds, and the number of people with diabetes is increasing in most countries. Wounds in diabetic people have a complex and prolonged treatment process, with high treatment costs to both healthcare providers and patients.

Fabrication and testing of polymer microneedles for transdermal drug delivery.

Microneedle (MN) patches have considerable potential for medical applications such as transdermal drug delivery, point-of-care diagnostics, and vaccination. These miniature microdevices should successfully pierce the skin tissues while having enough stiffness to withstand the forces imposed by penetration. Developing low-cost and simple manufacturing processes for MNs is of considerable interest.

An overview of microneedle applications, materials, and fabrication methods.

Microneedle-based microdevices promise to expand the scope for delivery of vaccines and therapeutic agents through the skin and withdrawing biofluids for point-of-care diagnostics - so-called theranostics. Unskilled and painless applications of microneedle patches for blood collection or drug delivery are two of the advantages of microneedle arrays over hypodermic needles. Developing the necessary microneedle fabrication processes has the potential to dramatically impact the health care delivery system by changing the landscape of fluid sampling and subcutaneous drug delivery.

High-resolution two-photon polymerization: the most versatile technique for the fabrication of microneedle arrays.

Microneedle patches have received much interest in the last two decades as drug/vaccine delivery or fluid sampling systems for diagnostic and monitoring purposes. Microneedles are manufactured using a variety of additive and subtractive micromanufacturing techniques. In the last decade, much attention has been paid to using additive manufacturing techniques in both research and industry, such as 3D printing, fused deposition modeling, inkjet printing, and two-photon polymerization (2PP), with 2PP being the most flexible method for the fabrication of microneedle arrays.

High-fidelity replication of thermoplastic microneedles with open microfluidic channels.

Development of microneedles for unskilled and painless collection of blood or drug delivery addresses the quality of healthcare through early intervention at point-of-care. Microneedles with submicron to millimeter features have been fabricated from materials such as metals, silicon, and polymers by subtractive machining or etching. However, to date, large-scale manufacture of hollow microneedles has been limited by the cost and complexity of microfabrication techniques.

Effects of neuropeptide Y on coronary artery vasomotion in patients with microvascular angina.

Background: Patients with microvascular angina (exertional angina, positive exercise tests and normal coronary arteriograms) usually have a reduced coronary blood flow reserve. Neuropeptide Y (NPY) is a potent endogenous vasoconstrictor involved in modulation of coronary vasomotor tone and may play a role in microvascular angina.

Methods: We compared the effects of NPY (0.

Plasma salicylate level and aspirin resistance in survivors of myocardial infarction.

To investigate the effect of aspirin on the platelets of survivors of myocardial infarction we correlated plasma salicylate level with platelet reactivity in ten patients and ten normal controls. The patients and controls were tested at the end of 2 week periods on 75, 150 and 300 mg aspirin daily by mouth. Platelet reactivity was measured, under high shear stress conditions, using cartridges containing adrenaline and adenosine diphosphate in a PFA-100 platelet function analyser.

Plasminogen activator inhibitor-1 removal using dextran sulphate columns. Evidence of PAI-1 homeostasis.

Patients with high plasma plasminogen activator inhibitor-1 (PAI-1) antigen levels are prone to develop thrombosis. Lowering PAI-1 levels may offer a therapeutic option and help to better understand PAI-1 metabolism. We examined the effect on plasma PAI-1 levels of LDL-apheresis using dextran sulphate (DS) columns in 12 patients (9 male, 3 female, 49 +/- 10 years) with heterozygous familial hypercholesterolaemia and coronary artery disease.

Elevated plasma lipid peroxide levels in angina pectoris and myocardial infarction.

Background: The concept that oxidised low-density lipoprotein (LDL), not native LDL, plays a major role in atherogenesis is gaining support. Lipid hydroperoxides in plasma are carried almost exclusively in LDL and reflect oxidised LDL. Previously, elevated plasma lipid hydroperoxides were reported in coronary artery disease (CAD) patients following bypass surgery.