Dendritic fibrous nanosilica: all-in-one nanomaterial for energy, environment and health

 

 Dendritic fibrous nanosilica (DFNS) attracted a great deal of attention in a large number of scientific disciplines such as catalysis, solar energy harvesting (photocatalysis, solar cells, etc.), energy storage,  self-cleaning antireflective coatings, surface plasmon resonance (SPR)-based ultra-sensitive sensors, CO2 capture, and biomedical applications (drug delivery, protein and gene delivery, bioimaging, photothermal ablation, Ayurvedic and radiotherapeutics drug delivery,
etc.). As discussed in this review, the unique fibrous morphology of the  DFNS family of materials bestows them with several important properties that were brilliantly exploited for use in a range of applications. The fibers of DFNS were functionalized with a range of organic groups, ionic liquids, organometallic complexes, polymers, peptides, enzymes, DNA, genes, etc. 

They were also loaded with metal nanoparticles, bi-metallic nanoparticles, even with single atoms of metals, quantum dots, and metal oxides and hydroxides. They were also used as hard templates for the synthesis of high surface area carbon with fibrous morphology. DFNS-based zeolites were also synthesized with unique
activities.

Dendritic fibrous nanosilica: all-in-one nanomaterial for energy, environment and health

Research could lead to new type of treatment for pancreatic cancer based on gold nanoparticles

A diagnosis of pancreatic cancer is often a death sentence because chemotherapy and radiation have little impact on the disease. In the U.S. this year, some 53,000 new cases will be diagnosed, and 42,000 patients will die of the disease, according to the National Institutes of Health. But research now being reported in ACS Nano could eventually lead to a new type of treatment based on gold nanoparticles.

Scientists have previously studied these tiny gold particles as a vehicle to carry chemotherapy drug molecules intotumors or as a target to enhance the impact of radiation on tumors. In addition, Priyabrata Mukherjee and colleagues previously found that gold nanoparticles themselves could limit tumor growth and metastasis in a model of ovarian cancer in mice.

Now, the team has determined that the same holds true for mouse models of pancreatic cancer. But interestingly, the new work revealed details about cellular communication in the area surrounding pancreatic tumors. By interrupting this communication -- which is partly responsible for this cancer's lethal nature -- the particles reduced the cell proliferation and migration that ordinarily occurs near these tumors. Gold nanoparticles of the size used in the new study are not toxic to normal cells, the researchers note.

New carbon nanomaterial pot several times deeper than any similar nanostructure

A novel, pot-shaped, carbon nanomaterial developed by researchers from Kumamoto University, Japan is several times deeper than any hollow carbon nanostructure previously produced. This unique characteristic enables the material to gradually release substances contained within and is expected to be beneficial in applications such as drug delivery systems.

Carbon is an element that is light, abundant, has a strong binding force, and eco-friendly. The range of carbon-based materials is expected to become more widespread in the eco-friendly society of the future. Recently, nanosized (one-billionth of a meter) carbon materials have been developed with lengths, widths, or heights below 100 nm. These materials take extreme forms such as tiny grained substances, thin sheet-like substances, and slim fibrous substances. Example of these new materials are fullerenes, which are hollow cage-like carbon molecules; carbon nanotubes, cylindrical nanostructures of carbon molecules; and graphene, one-atom thick sheets of carbon molecules.

Why are these tiny substances needed? One reason is that reactions with other materials can be much larger if a substance has an increased surface area. When using nanomaterials in place of existing materials, it is possible to significantly change surface area without changing weight and volume, thereby improving both size and performance. The development of carbon nanomaterials has provided novel nanostructured materials with shapes and characteristics that surpass existing materials.

Now, research from the laboratory of Kumamoto University's Associate Prof. Yokoi has resulted in the successful development of a container-type carbon nanomaterial with a much deeper orifice than that found in similar materials. To create the new material, researchers used their own, newly developed method of material synthesis. The container-shaped nanomaterial has a complex form consisting of varied layers of stacked graphene at the bottom, the body, and the neck areas of the container, and the graphene edges along the outer surface of the body were found to be very dense. Due to these innovate features, Associate Prof. Yokoi and colleagues named the material the "carbon nanopot."

New carbon nanomaterial pot several times deeper than any similar nanostructure

New research delves into physical properties of nanoparticles for successful drug delivery

Nanoparticles are being studied as drug delivery systems to treat a wide variety of diseases. New research delves into the physical properties of nanoparticles that are important for successfully delivering therapeutics within the body, with a primary focus on size. This is especially important as relatively subtle differences in size can affect cell uptake and determine the fate of nanoparticles once within cells.

By exploring various strategies for fabricating nanoparticles, the investigators provide valuable information for generating uniform nanoparticles in high yields that will be efficiently taken up by target cells.

New research delves into physical properties of nanoparticles for successful drug delivery

Scientists develop graphene-based sensor that can detect harmful air pollution in home

Scientists develop graphene-based sensor that can detect harmful air pollution in home: Scientists from the University of Southampton, in partnership with the Japan Advanced Institute of Science and Technology, have developed a graphene-based sensor and switch that can detect harmful air pollution in the home with very low power consumption.

Novel nanoparticle drug delivery system for enhanced tumor penetration of cancer drugs

Novel nanoparticle drug delivery system for enhanced tumor penetration of cancer drugs: For more than a decade, biomedical researchers have been looking for better ways to deliver cancer-killing medication directly to tumors in the body. Tiny capsules, called nanoparticles, are now being used to transport chemotherapy medicine through the bloodstream, to the doorstep of cancerous tumors.

Plaque-busting nanoparticles could help fight tooth decay

Nanotechnology might soon save you a trip to the dentist. Researchers have developed tiny sphere-shaped particles that ferry a payload of bacteria-slaying drugs to the surface of the teeth, where they fight plaque and tooth decay on the spot. The approach could also be adapted to combat other plaquelike substances, known as biofilms, such as those that form on medical devices like orthopedic implants.

"It's quite clever," says oral microbiologist Robert Allaker of Queen Mary University of London, who was not involved with the research. "I think it was an innovative piece of work."

Plaque is a film made up of bacteria and a matrix of polymers composed of linked sugars, which clings tenaciously to teeth. When bacteria digest sugars in the mouth, they produce acid as a byproduct, which eats away at teeth, eventually causing decay. Topical antibacterial drugs don’t work well on plaque because saliva quickly washes them away.

Nanoparticles can solve this problem by clinging to the surface of teeth and carrying drugs along with them. Although this is not the first technique to employ such a strategy, the research improves upon previous methods, because these particles attach not only to the tooth, but also to the plaque biofilm.

Plaque-busting nanoparticles could help fight tooth decay  

Engineers now understand how complex carbon nanostructures form

CNTs are much smaller than the width of a human hair and naturally form "forests" when they are created in large numbers. These forests, held together by a nanoscale adhesive force known as the van der Waals force, are categorized based on their rigidity or how they are aligned. For example, if CNTs are dense and well aligned, the material tends to be more rigid and can be useful for electrical and mechanical applications. If CNTs are disorganized, they tend to be softer and have entirely different sets of properties.

"Scientists are still learning how carbon nanotube arrays form," said Matt Maschmann, assistant professor of mechanical and aerospace engineering in the College of Engineering at MU. "As they grow in relatively dense populations, mechanical forces combine them into vertically oriented assemblies known as forests or arrays. The complex structures they form help dictate the properties the CNT forests possess. We're working to identify the mechanisms behind how those forests form, how to control their formation and thus dictate future uses for CNTs."

Currently, most models that examine CNT forests analyze what happens when you compress them or test their thermal or conductivity properties after they've formed. However, these models do not take into account the process by which that particular forest was created and struggle to capture realistic CNT forest structure.

Engineers now understand how complex carbon nanostructures form 

Carbon nanotube fibers make superior links to brain

Carbon nanotube fibers invented at Rice University may provide the best way to communicate directly with the brain.

The fibers have proven superior to metal electrodes for deep brain stimulation and to read signals from a neuronal network. Because they provide a two-way connection, they show promise for treating patients with neurological disorders while monitoring the real-time response of neural circuits in areas that control movement, mood and bodily functions.

New experiments at Rice demonstrated the biocompatible fibers are ideal candidates for small, safe electrodes that interact with the brain's neuronal system, according to the researchers. They could replace much larger electrodes currently used in devices for deep brain stimulation therapies in Parkinson's disease patients.

They may also advance technologies to restore sensory or motor functions and brain-machine interfaces as well as deep brain stimulation therapies for other neurological disorders, including dystonia and depression, the researchers wrote.

The paper appeared online this week in the American Chemical Society journal ACS Nano.

The fibers created by the Rice lab of chemist and chemical engineer Matteo Pasquali consist of bundles of long nanotubes originally intended for aerospace applications where strength, weight and conductivity are paramount.

The individual nanotubes measure only a few nanometers across, but when millions are bundled in a process called wet spinning, they become thread-like fibers about a quarter the width of a human hair.

"We developed these fibers as high-strength, high-conductivity materials," Pasquali said. "Yet, once we had them in our hand, we realized that they had an unexpected property: They are really soft, much like a thread of silk. Their unique combination of strength, conductivity and softness makes them ideal for interfacing with the electrical function of the human body."

Carbon nanotube fibers make superior links to brain  

Nanofibers twisted together to create structures tougher than bullet proof vests -- ScienceDaily

Researchers at the University of Texas at Dallas have created new structures that exploit the electromechanical properties of specific nanofibers to stretch to up to seven times their length, while remaining tougher than Kevlar.

Nanofibers twisted together to create structures tougher than bullet proof vests  

Researchers develop durable antibacterial coatings of nanocomposites

Researchers develop durable antibacterial coatings of nanocomposites

Biomedical use of gold nanotubes demonstrated in mouse model of human cancer

Scientists have shown that gold nanotubes have many applications in fighting cancer: internal nanoprobes for high-resolution imaging; drug delivery vehicles; and agents for destroying cancer cells.

The study, published today in the journal Advanced Functional Materials, details the first successful demonstration of the biomedical use of gold nanotubes in a mouse model of human cancer.

Study lead author Dr Sunjie Ye, who is based in both the School of Physics and Astronomy and the Leeds Institute for Biomedical and Clinical Sciences at the University of Leeds, said: "High recurrence rates of tumours after surgical removal remain a formidable challenge in cancer therapy. Chemo- or radiotherapy is often given following surgery to prevent this, but these treatments cause serious side effects.

Gold nanotubes - that is, gold nanoparticles with tubular structures that resemble tiny drinking straws - have the potential to enhance the efficacy of these conventional treatments by integrating diagnosis and therapy in one single system."

The researchers say that a new technique to control the length of nanotubes underpins the research. By controlling the length, the researchers were able to produce gold nanotubes with the right dimensions to absorb a type of light called 'near infrared'.

Biomedical use of gold nanotubes demonstrated in mouse model of human cancer

Why 'baking powder' doubles or triples efficiency of plastic solar cells

Why 'baking powder' doubles or triples efficiency of plastic solar cells 

Nano-hydrogels that attack cancer cells

Hydrogels are materials that are commonly used in everyday objects such as contact lenses or diapers, in order to control humidity. However, chemical engineers at the University of Guadalajara (UdeG), in Mexico, developed a new technology based on thermosensitive nanoparticles (nano-hydrogels) to use these materials in the field of biomedicine, as an alternative to achieve controlled release of anticancer drugs.

Nano-hydrogels that attack cancer cells  

Gold 'nano-drills' help with DNA analysis

Researcher Lennart de Vreede applied a large number of microscopic discs of gold on a surface of silicon dioxide. When heated up for several hours, the gold is moving into the material, perpendicular to the surface, like nanometer-sized spheres. Nine hours of heating gives a tunnel of 800 nanometers in length, for example, and a diameter of 25 nanometer: these results can normally only be acieved by using complex processes. The gold can even fully move through the material. All nanotunnels together then form a sieve. Leaving the tunnel closed at one end, leaves open the possibility of creating molds for nano structures.

Once heating to close to their melting point, the gold discs -- diameter one micron -, don't spread out over the surface, but they form spheres. They push away the siliciumdioxide, causing a circular 'ridge', a tiny dam. While moving into the silicondioxide, the ball gets smaller: it evaporates and there is a continuos movement of silicondioxide.

For example in DNA-sequencing applications, De Vreede sees applications for this new fabrication technology. In that case, a DNA-string is pulled through one of these nano-channels, after which the building blocks of DNA, the nucleotides, can be analysed subsequently. Furthermore, De Vreede expects the 'gold method' to be applicable to other ceramic materials as well. His recent experiments on silicium nitride indicate that.

Gold 'nano-drills' help with DNA analysis 

NC State researchers develop wearable nanowire sensor to monitor electrophysiological signals

Researchers from North Carolina State University have developed a new, wearable sensor that uses silver nanowires to monitor electrophysiological signals, such as electrocardiography (EKG) or electromyography (EMG). The new sensor is as accurate as the "wet electrode" sensors used in hospitals, but can be used for long-term monitoring and is more accurate than existing sensors when a patient is moving.

Long-term monitoring of electrophysiological signals can be used to track patient health or assist in medical research, and may also be used in the development of new powered prosthetics that respond to a patient's muscular signals.

Electrophysiological sensors used in hospitals, such as EKGs, use wet electrodes that rely on an electrolytic gel between the sensor and the patient's skin to improve the sensor's ability to pick up the body's electrical signals. However, this technology poses problems for long-term monitoring, because the gel dries up - irritating the patient's skin and making the sensor less accurate.

The new nanowire sensor is comparable to the wet sensors in terms of signal quality, but is a "dry" electrode - it doesn't use a gel layer, so doesn't pose the same problems that wet sensors do.

NC State researchers develop wearable nanowire sensor to monitor electrophysiological signals

"Extra-short nanowires best for brain"

If in the future electrodes are inserted into the human brain - either for research purposes or to treat diseases - it may be appropriate to give them a 'coat' of nanowires that could make them less irritating for the brain tissue. However, the nanowires must not exceed a certain length, according to new research from Neuronano Research Center at Lund University in Sweden.

Nanotechnology Now - Press Release: "Extra-short nanowires best for brain"

Nanotechnology Now - Press Release: "Gold nanoparticles show promise for early detection of heart attacks: NYU School of Engineering Professors collaborate with researchers from Peking University on a new test strip"

Nanotechnology Now - Press Release: "Gold nanoparticles show promise for early detection of heart attacks: NYU School of Engineering Professors collaborate with researchers from Peking University on a new test strip"

'Glowing' new nanotechnology guides cancer surgery, also kills remaining malignant cells..

Researchers at Oregon State University have developed a new way to selectively insert compounds into cancer cells -- a system that will help surgeons identify malignant tissues and then, in combination with phototherapy, kill any remaining cancer cells after a tumor is removed.

It's about as simple as, "If it glows, cut it out." And if a few malignant cells remain, they'll soon die.

The findings, published in the journal Nanoscale, have shown remarkable success in laboratory animals. The concept should allow more accurate surgical removal of solid tumors at the same time it eradicates any remaining cancer cells. In laboratory tests, it completely prevented cancer recurrence after phototherapy.

Technology such as this, scientists said, may have a promising future in the identification and surgical removal of malignant tumors, as well as using near-infrared light therapies that can kill remaining cancer cells, both by mild heating of them and generating reactive oxygen species that can also kill them.

"This is kind of a double attack that could significantly improve the success of cancer surgeries," said Oleh Taratula, an assistant professor in the OSU College of Pharmacy.

"With this approach, cancerous cells and tumors will literally glow and fluoresce when exposed to near-infrared light, giving the surgeon a precise guide about what to remove," Taratula said. "That same light will activate compounds in the cancer cells that will kill any malignant cells that remain. It's an exciting new approach to help surgery succeed."

'Glowing' new nanotechnology guides cancer surgery, also kills remaining malignant cells --  

Germanium: Semiconductor milestone

A laboratory at Purdue University provided a critical part of the world's first transistor in 1947 -- the purified germanium semiconductor -- and now researchers there are on the forefront of a new germanium milestone. The team has created the first modern germanium circuit -- a complementary metal-oxide-semiconductor (CMOS) device -- using germanium as the semiconductor instead of silicon.

The team has created the first modern germanium circuit -- a complementary metal-oxide-semiconductor (CMOS) device -- using germanium as the semiconductor instead of silicon.

"Bell Labs created the first transistor, but the semiconductor crystal made of purified germanium was provided by Purdue physicists," said Peide "Peter" Ye, a Purdue professor of electrical and computer engineering.

Germanium was superseded by silicon as the semiconductor of choice for commercial CMOS technology. However, the industry will soon reach the limit as to how small silicon transistors can be made, threatening future advances. Germanium is one material being considered to replace silicon because it could enable the industry to make smaller transistors and more compact integrated circuits, Ye said.

Compared to silicon, germanium also is said to have a "higher mobility" for electrons and electron "holes," a trait that makes for ultra-fast circuits.

In new findings, Purdue researchers show how to use germanium to produce two types of transistors needed for CMOS electronic devices. The material had previously been limited to "P-type" transistors. The findings show how to use the material also to make "N-type" transistors. Because both types of transistors are needed for CMOS circuits, the findings point to possible applications for germanium in computers and electronics, he said.

Findings will be detailed in two papers being presented during the 2014 IEEE International Electron Devices Meeting on Dec. 15-17 in San Francisco. One paper was authored by Ye and graduate students Heng Wu, Nathan Conrad and Wei Luo, the same authors of the second paper together with graduate students Mengwei Si, Jingyun Zhang and Hong Zhou.

Germanium: Semiconductor milestone