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