Seeing Nanoparticles in 3D Within Animal Tissues

Seeing Nanoparticles in 3D Within Animal Tissues

Understanding the pharmacokinetics and distribution of nanoparticles has always been challenging. Researchers can quantify accumulation at the organ level, but at the expense of cellular detail. Or they can quantify accumulation at the cellular level, but at the expense of 3D tissue architecture detail. Given that nanomedicine is a delivery-based therapy, it’s important to know the delivery destinations of nanoparticles. As the field of nanomedicine shifts towards understanding cell-nanoparticle interactions, this gap needs to be addressed: where exactly are the nanoparticles going? Researchers in Dr. Warren Chan’s lab at the University of Toronto have developed a method to create whole tissue maps to answer this question. They adapted a technique that makes tissues transparent (CLARITY), and used it to visualize nanoparticle distribution deep inside tissues. They take advantage of the layer of proteins that form around nanoparticles and cross-linked it to hold the nanoparticles in place. Additionally, they created a high-throughput system that can process 48 tissues simultaneously. In a proof-of-concept paper published in ACS Nano, they used quantum dots as a model nanoparticle and showed its distribution in the liver, kidney, and spleen. They observed most of the particles to be inside or on the blood vessels, indicating potential endothelial cell or macrophage uptake. Further, they developed algorithms to quantify the distribution by assessing how far the particles could penetrate past the blood vessels into tissues; in the liver, the limit seems to be 20 μm (a few cells thick). “This paper represents a tour-de-force in uncovering how nanoparticles distribute themselves in tissues and tumors,” said Teri Odom, a professor of Materials Science & Engineering at Northwestern University who was...
Super Accurate Opto-Microfluidic Chip to Measure Glucose in Sweat

Super Accurate Opto-Microfluidic Chip to Measure Glucose in Sweat

At the Hong Kong Polytechnic University and Zhejiang University in China, researchers have developed a highly sensitive glucometer integrated inside an opto-microfluidic device. Electrochemical sensors can be used instead of optical components, but they’re subject to interference and can produce inconsistent results. The new sensor can detect glucose oxidase at concentrations below 1 nM (10-9 molarity). The researchers believe that such impressive sensitivity may allow the development of small devices that stick to the skin and measure glucose from sweat. Some of the details according to the study abstract in Biomedical Optics Express: A long-period grating (LPG) inscribed in a small-diameter single-mode fiber (SDSMF) is employed as an optical refractive-index (RI) sensor. With the layer-by-layer (LbL) self-assembly technique, poly (ethylenimine) (PEI) and poly (acrylic acid) (PAA) multilayer film is deposited on the SDSMF-LPG sensor for both supporting and signal enhancement, and then a glucose oxidase (GOD) layer is immobilized on the outer layer for glucose sensing. A microfluidic chip for glucose detection is fabricated after embedding the SDSMF-LPG biosensor into the microchannel of the chip. Experimental results reveal that the SDSMF-LPG biosensor based on such a hybrid sensing film can ultrasensitively detect glucose concentration as low as 1 nM. After integration into the microfluidic chip, the detection range of the sensor is extended from 2 µM to 10 µM, and the response time is remarkablely shortened from 6 minutes to 70 seconds. Study in Biomedical Optics Express: Optical fiber LPG biosensor integrated microfluidic chip for ultrasensitive glucose detection… Via: Optical Society… The post Super Accurate Opto-Microfluidic Chip to Measure Glucose in Sweat appeared first on...
Device Captures Circulating Tumor Cells, Keeps Them Alive for Testing

Device Captures Circulating Tumor Cells, Keeps Them Alive for Testing

Fluorescence probes in two breast cancer cells give information about which genes are present. The green dots show that both cells have multiple copies of the HER2 gene, suggesting that the cancer is aggressive. Credit: Nallasivam Palanisamy, Henry Ford Health System. Images copyright: Advanced Materials Circulating tumor cells (CTCs) that dislodge from a primary tumor and travel through the blood stream can spread the disease, but can also be valuable for monitoring how a therapy is working. There are now quite a few devices out there that have been developed that filter out CTCs from whole blood, but keeping the cells alive and making them available for further laboratory testing has been difficult. Researchers at the University of Michigan have now created a microfluidic device that does just that. Previously it was possible to use graphene oxide, incredibly thin sheets of carbon and oxygen, to capture CTCs, but they remained stuck to the material. Heating or using chemical reactions to remove the cells does damage to them, so the researchers used a newly developed polymer that breaks up at a preset temperature to solve the problem. Bits of graphene oxide were mixed with the polymer that would dissolve below 54 degrees. Using previously developed techniques, the CTCs were captured, but this time a bit of cooling forced the polymer to break up and release the CTCs. The researchers report that about 80% of the caught cells were alive when released, which bodes well for the future of cancer management via rapid CTC detection. Study in Advanced Materials: Tunable Thermal-Sensitive Polymer–Graphene Oxide Composite for Efficient Capture and Release of Viable Circulating Tumor Cells… Via:...
Catheter Coating Detects Infections, Notifies Clinicians

Catheter Coating Detects Infections, Notifies Clinicians

Urinary catheter infections are a notorious bane for clinicians taking care of patients with indwelling catheters. Those on long term management are forced to take antibiotics to prevent infections, while infections still occur, blocking the catheter’s lumen and causing a variety of side effects. Being able to detect that a catheter is infected can help prevent antibiotic resistance, lessen the burden on clinicians, reduce costs, and certainly lead to better clinical outcomes for patients. At the University of Bath in England, researchers have created a novel coating that can be applied to catheter tips that changes the color of urine flowing into collection bags. Strangely, the color that ended up being used is bright yellow, hopefully bright and yellow enough to differentiate itself from urine. But the interesting thing is that the coating has two layers. One reacts to pH levels above 8, which happens to urine in the presence of a bacterial infection, breaking down and revealing the layer below that contains a gel infused with a non-toxic dye. The gel is released and the dye can be noticed inside the collection bag. In a laboratory study, the researchers showed that their system can detect bacterial infections within catheters at least twelve hours prior to a blockage. Of course clinical studies would need to be conducted to confirm the technology, but considering the extent of the problem we may soon see its application at your local hospital. Study in Biosensors and Bioelectronics: An in-situ infection detection sensor coating for urinary catheters… Via: University of Bath… The post Catheter Coating Detects Infections, Notifies Clinicians appeared first on...
Hardware-In-The-Loop Helps to Develop New Medical Devices

Hardware-In-The-Loop Helps to Develop New Medical Devices

Researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart, Germany have been working on translating hardware-in-the-loop development approaches, the same ones used extensively in the auto industry, to create new medical devices. For cars, the technique relies on using a computer to simulate varying situations that different hardware components may end up encountering. This happens throughout the development process, using a large set of tests, so there’s no waiting for the hardware to be created before important testing can begin and flaws are discovered early so fixes are made before a prototype is even built. The team has demonstrated the approach for developing a cardiac assist device and have worked with the Dutch firm Soteria Medical to help it create control systems for a new biopsy product. More details from Fraunhofer… The post Hardware-In-The-Loop Helps to Develop New Medical Devices appeared first on...