Nanomedicine Archives

Separating circulating tumor cells (CTC) out of blood is a difficult process because of their very low relative count. Researchers from Cornell University were able to use naturally occurring halloysite nanotubes, found in halloysite clay and separated and purified by a startup called NaturalNano (Rochester, NY), to improve the capture of CTC’s from blood.
From the study abstract:

In this study, we explore a method to more efficiently capture leukemic and epithelial cancer cells from flow by altering the nanoscale topography of the inner surface of P-selectin-coated microtubes. This functionalized topography is achieved by attaching naturally occurring halloysite nanotubes to the microtube surface via a monolayer of poly-l-lysine), followed by functionalization with recombinant human selectin protein. We have found that halloysite nanotube coatings promote increased capture of leukemic cells and have determined the key parameters for controlling cell capture under flow: halloysite content and selectin density. Ultimately, selectin-functionalized nanotube coatings should provide a means for enhanced cancer cell isolation from whole blood and other mixtures of cells.

Press release: Cancer Treatment Personalized With Nano-Materials …
Abstract in Langmuir: Use of Naturally Occurring Halloysite Nanotubes for Enhanced Capture of Flowing Cells
Technology page at NaturalNano: Halloysite Nanotubes…
Image: A bundle of NaturalNano halloysite nanotubes compared to the width of a human hair (NaturalNano).

Michael Berger over at Nanowerk is reporting on a nanomechanical sensor for the detection of cholera developed by scientists at Northwestern University and University of Illinois at Urbana-Champaign. The system utilizes synthetic membrane models called nanodiscs and cantilevers on a nano scale to perform the sensing.
A snippet from Nanowerk:

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Researchers from MIT and Brigham and Women’s Hospital used specially designed nanoparticles to deliver two very different chemo drugs, cisplatin and docetaxel, to prostate cancer cells. Because docetaxel is hydrophobic and cisplatin is hydrophilic encapsulating them in one nanoparticle is a difficult task.

With the researchers’ new technique, called “drug-polymer blending,” drug molecules are hung like pendants from individual units of the polymer, before the units assemble into a polymer nanoparticle. That allows the researchers to precisely control the ratio of drugs loaded into the particle. They can also control the rate at which each drug will be released once it enters a tumor cell.

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Two months ago we reported that University of Pennsylvania researchers were able to create a tiny nanopore within graphene, sheet of carbon one atom thick, and detect DNA molecules passing through the opening. Now a collaboration of scientists from Harvard and MIT is reporting in a cover story in Nature that they were able to measure the ionic flow through a nanopore of their own making. They studied the properties of graphene when it’s separating two ionically variable liquids and showed graphene sheets function as “ionic insulators with a very small stable conductance that depends on the ion species in solution.”

The graphene was stretched over a silicon-based frame, and inserted between two separate liquid reservoirs. An electrical voltage applied between the reservoirs pushed the ions towards graphene membrane. When a nanopore was drilled through the membrane, this voltage channeled the flow of ions through the pore and registered as an electrical current signal.

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Scientists at Northwestern University have stumbled serendipitously onto a method to create nanostructures called metal-organic frameworks… which also happen to be edible. Metal-organic frameworks are metals connected in a highly organized crystal structure that allows for the trapping, storage, and controlled release of gas (i.e: hydrogen or carbon dioxide) or other molecules. These structures have been proposed as a possible new targeted drug delivery system that can be seen on imaging. They also have many non-medical uses such as for gas purification and for gas storage.
Usually metal organic frameworks are made from toxic petroleum-based products. The secret to Northwestern’s great gastronomical success is gamma-cyclodextrin, a sugar produced from corn starch. Add in a little alcohol in the form of Everclear (no joke), and the scientists accidentally ended up with a huge breakthrough.

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Researchers at Lund University in Sweden successfully used magnets to guide fibrinolytics (clot dissolving drugs) directly to the site of a thrombus stuck within a coronary stent. They did this by attaching the drugs to magnetic nanoparticles and using external magnets to move them to the right spot.

Guiding drug-loaded magnetic particles using a magnet outside the body is not a new idea. However, previous attempts have failed for various reasons: it has only been possible to reach the body’s superficial tissue and the particles have often obstructed the smallest blood vessels.

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McGill University scientists have developed a way to place electric charges onto quantum dots (particles sized

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Researchers at Arizona State University have created a device called Integrascope that can supposedly make detection of infectious diseases and measurement of protein levels cheaper and faster. The system uses a water-repellent surface to form blood into a properly shaped drop that can focus infrared light shone through it. Nanoparticles placed on top of the drop agglutinate in the presence of infectious agents or specific proteins.
Details from an ASU press release:

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