The new particles, just tens of nanometers across, are made of diamond and covered in silk. They can be injected into living cells, and because they glow when illuminated with certain kinds of light, biologists can use them to peer inside cells and untangle the molecular circuitry that governs cellular behavior, or to study how cells react to a new drug.
The nanodiamond-silk material, which was implanted into living tissue for two weeks, left no signs of inflammation, suggesting that it's safe for the body.
Credit: Biomedical Optics Express
This is an illustration of nanodiamonds seeded on a marked silicon substrate and coated with silk film.
Credit: Asma Khalid
The silk-coated diamond particles could also potentially be used someday in the clinic, by allowing doctors to send infection-fighting antibiotics to a targeted area of the body.
A team of researchers from Australia and the United States describes this new hybrid diamond-silk material in a paper published today in The Optical Society's (OSA) journal Biomedical Optics Express.
Nanodiamonds similar to those in this study have been explored previously for their potential medical uses, but this is the first time silk has been incorporated with nanodiamonds, said Asma Khalid of the University of Melbourne, who is the first author of the Biomedical Optics Express paper. "This nanodiamond-silk hybrid material is important due to the potential it offers to the fields of bioimaging, biosensing and drug delivery," she explained.
Diamonds are crystals of carbon. But they can be made with defects—other atoms inserted in the crystal structure—and these defects allow them to do tricks that flawless diamonds can't, such as absorbing and reemitting light of certain wavelengths, a process called fluorescence. Because these fluorescent nanodiamonds are bright, stable, and harmless to living tissue – and can work at room temperature – researchers have been exploring their use in biological imaging and sensing. But the edges around the particles tend to be rough and may cause the nanodiamonds to become trapped inside cell membranes.
Previously, other researchers have addressed this problem by coating the particles with lipids, a class of molecules found in fats and waxes. According to the new study, however, a better solution is to cover the nanodiamonds in silk, which is transparent, flexible, compatible with biological tissue, and biodegradable, so it won't leave any harmful byproducts inside the body.
When the researchers tested their new hybrid material, they found that the silk remains transparent, meaning that it does not block the glow of the nanodiamonds. They also discovered that the silk not only preserves the optical properties of the nanodiamonds, but it enhances their brightness by two to four times. Finally, the new material appears to be safe for use in the body: it left no damaging effects even after spending two weeks implanted inside living tissue, suggesting that it is nontoxic and non-inflammatory, the researchers say.
In the future, the team envisions a range of nanodiamond-silk structures that could help researchers improve techniques for fighting infections in targeted areas of the body. A thin film of the new substance, carrying drugs, could be implanted directly into an infected area, minimizing the patient's exposure to the drugs. Silk can also be designed to degrade at a certain rate, which would allow clinicians to control the release of medications.
In addition to the University of Melbourne, the researchers are affiliated with the University of Sydney and the Silk Lab at Tufts University in Massachusetts.
Paper: "Synthesis and Characterization of Biocompatible Nanodiamond-Silk Hybrid Material," Khalid, A. et al., Biomedical Optics Express, Vol. 5, Issue 2, pp. 596-608 (2014).
EDITOR'S NOTE: High-resolution images are available to members of the media upon request. Contact Angela Stark, email@example.com.
About Biomedical Optics Express
Biomedical Optics Express is OSA's principal outlet for serving the biomedical optics community with rapid, open-access, peer-reviewed papers related to optics, photonics and imaging in the life sciences. The journal scope encompasses theoretical modeling and simulations, technology development, and biomedical studies and clinical applications. It is published by The Optical Society and edited by Joseph A. Izatt of Duke University. Biomedical Optics Express is an open-access journal and is available at no cost to readers online at http://www.OpticsInfoBase.org/BOE.
Founded in 1916, The Optical Society (OSA) is the leading professional society for scientists, engineers, students and business leaders who fuel discoveries, shape real-world applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership programs, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of professionals in optics and photonics.
Angela Stark | EurekAlert!
About injured hearts that grow back - Heart regeneration mechanism in zebrafish revealed
10.02.2016 | Universität Ulm
Chemical cages: New technique advances synthetic biology
10.02.2016 | Arizona State University
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications.
Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes...
09.02.2016 | Event News
02.02.2016 | Event News
26.01.2016 | Event News
10.02.2016 | Life Sciences
10.02.2016 | Earth Sciences
10.02.2016 | Physics and Astronomy