"It is the first luminescent nanoparticle that was purposely designed to minimize toxic side effects," said Michael Sailor, a chemistry professor at the University of California, San Diego who led the study.
Many nanoparticles tested in research labs are too poisonous for use in humans.
"This new design meets a growing need for non-toxic alternatives that have a chance to make it into the clinic to treat human patients," Sailor said.
The particles inherently glow, a useful property that is most commonly achieved by including toxic organic chemicals or tiny structures called quantum dots, which can leave potentially harmful heavy metals in their wake.
When the researchers tested their safer nanoparticles in mice, they saw tumors glow for several hours, then dim as the particles broke down. Levels dropped noticeably in a week and were undetectable after four weeks, they report in Nature Materials February 22.
This is the first sudy to image tumors and organs using biodegradable silicon nanoparticles in live animals, the authors say.
The particles begin as thin wafers made porous with an electrical current then smashed to bits with ultrasound. Additional treatment alters the physical structure of the flakes to make them glow red when illuminated with ultraviolet light.
Luminescent particles can reveal tumors too tiny to detect by other means or allow a surgeon to be sure all of a cancerous growth has been removed.
These nanoparticles could also help deliver drugs safely, the researchers report. The cancer drug doxorubicin will stick to the pores and slowly escape as the silicon dissolves.
"The goal is to use the nanoparticles to chaperone the drug directly to the tumor, to release it into the tumor rather than other parts of the body," Sailor said.
Targeted delivery would allow doctors to use smaller doses of the drug. At doses high enough to be effective, when delivered to the whole body, doxorubicin often has toxic side effects.
At about 100 nanometers, these particles are bigger than many designed to deliver drugs, which can be just a few nanometers across – a thousand times smaller than the diameter of a human hair.
Their larger size contributes to both their effectiveness and their safety. Large particles can hold more of a drug. Yet they self-destruct, and the remnants can be filtered away by the kidneys.
Close examination of vulnerable organs like liver, spleen and kidney, which help to remove toxins, revealed no lasting changes in mice treated with the new nanoparticles.
Graduate students Ji-Ho Park and Luo Gu in Sailor's lab; Sangeeta Bhatia, bioengineering professor at the Massachusetts Institute of Technology and graduate student Geoffrey von Malzahn in Bhatia's lab; and Erkki Ruoslahti, professor at the University of California, Santa Barbara all contributed to this work.
The National Cancer Institute and the National Science Foundation funded this research.
Michael Sailor | EurekAlert!
Research reveals how diabetes in pregnancy affects baby's heart
13.12.2017 | University of California - Los Angeles Health Sciences
Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Information Technology
13.12.2017 | Physics and Astronomy
13.12.2017 | Health and Medicine