Researchers at the University of Illinois have discovered an easy method to produce carbon nanoparticles for biomedical applications. These carbon nanoparticles can be made at home within a couple of hours using easily available ingredients and molasses.
University of Illinois postdoctoral researcher Prabuddha Mukherjee, left, bioengineering professors Rohit Bhargava and Dipanjan Pan, and postdoctoral researcher Santosh Misra report the development of a new class of carbon nanoparticles for biomedical use. Photo by L. Brian Stauffer
The carbon nanoparticles produced using this new method are small enough for carrying pharmaceutical drugs to specifically targeted tissues. These nanoparticles can be easily detected as they are able to reflect light in the near-infrared range. Additionally, their small size allows them to elude the immune system of the body.
Dipanjan Pan and Rohit Bhargava, bioengineering professors at the University of Illinois, have led this study.
The researchers observed that these carbon nanoparticles had a number of interesting properties. The differences between these particles and human tissue could be easily observed, as they scattered light in a specific manner. This avoided the necessity of using any fluorescing molecules or dyes for detecting them when they were within the human body.
The team coated the nanoparticles with polymers to optimize their optical properties and the rate at which they degraded within the body. Pharmaceutical drugs can be loaded on to these polymers and would get released gradually when they were in the body. The nanoparticles produced using this method have a diameter of less than 8nm. Comparatively, the human hair ranges in thickness from 80,000nm - 100,000nm.
If you have a microwave and honey or molasses, you can pretty much make these particles at home. You just mix them together and cook it for a few minutes, and you get something that looks like char, but that is nanoparticles with high luminescence. This is one of the simplest systems that we can think of. It is safe and highly scalable for eventual clinical use.
Dipanjan Pan
Our immune system fails to recognize anything under 10 nanometers. So, these tiny particles are kind of camouflaged, I would say; they are hiding from the human immune system.
Dipanjan Pan
The therapeutic potential of the carbon nanoparticles was then analyzed. An anti-melanoma drug was loaded onto these nanoparticles and then mixed in a topical solution. This mixture was then applied to the skin of a pig. The molecular structure of the carbon nanoparticles and their drug payload was identified using vibrational spectroscopic techniques at Bhargava’s laboratory.
Raman and infrared spectroscopy are the two tools that one uses to see molecular structure. We think we coated this particle with a specific polymer and with specific drug-loading – but did we really? We use spectroscopy to confirm the formulation as well as visualize the delivery of the particles and drug molecules.
Bhargava
The study revealed that the drug cargo was not released by the nanoparticles at room temperature, but released by them at body temperature. Furthermore, the topical applications that were able to penetrate the skin to the preferred depth were also determined.
Additionally, altering the polymer coatings helped change the nanoparticle infusion into melanoma cells. This infusion caused the cells to enlarge, which signified that it would eventually die. This swelling was confirmed through imaging.
“This is a versatile platform to carry a multitude of drugs – for melanoma, for other kinds of cancers and for other diseases,” Bhargava said. “You can coat it with different polymers to give it a different optical response. You can load it with two drugs, or three, or four, so you can do multidrug therapy with the same particles.”
“By using defined surface chemistry, we can change the properties of these particles,” Pan said. “We can make them glow at a certain wavelength and also we can tune them to release the drugs in the presence of the cellular environment. That is, I think, the beauty of the work.”
The findings of this study have been published in the journal, Small.
University of Illinois faculty members belonging to the mechanical science and engineering, electrical and computer engineering, chemistry, and chemical and biomolecular engineering have taken part in this study. Researchers from the Illinois Sustainable Technology Center, and the Materials Research Laboratory at Illinois have also contributed to this study. Bhargava and Pan are associated with the Carle Foundation Hospital, and they are also faculty members at the Illinois Beckman Institute for Advanced Science and Technology.
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