Particles of nicotine on patches attached to the skin succeed in penetrating the body and help wean the wearer off smoking – but only because the particles are no larger than 100 nanometers (each of which is one-thousandth of a centimeter).
For other molecules to enter the skin – one of the largest and most accessible organs in the human body – it is impossible for medicinal and even cosmetic treatments to penetrate the deep layers. Because the particles are so small and difficult to see, it is equally challenging to determine their exact location inside the body – information needed to ensure that they reach intended target tissue. Today, such information is obtained through invasive and often painful biopsies.
But a new approach developed by researchers at Bar-Ilan University (BIU) in Ramat Gan provides an innovative solution to overcoming both of these barriers. Combining techniques in nanotechnology and optics, they produced nanometric diamond particles so small they can penetrate skin to deliver a variety of remedies. In addition, they created a safe, laser-based optical method that quantifies nanodiamond penetration into the various layers of the skin and determines their location and concentration within body tissue in a noninvasive manner – even eliminating the need for some biopsies.
Carbon-based nanodiamonds are currently made by detonating an explosive in a reactor vessel to provide heat and pressure. The diamond particles must then be removed and purified from contaminating elements massed around them. The process is quick and cheap, but the nanodiamonds aggregate and are of varying size and purity.
They can be used as antimicrobial agents due to some of their properties, including size, shape and biocompatibility. That makes them highly suitable for the development of efficient and tailored nanotherapies, including vaccines or drug delivery.
This innovation was just published under the title “Noninvasive Nanodiamond Skin Permeation Profiling Using a Phase Analysis Method: Ex Vivo Experiments” in the scientific journal ACS Nano by researchers at BIU’s Institute of Nanotechnology and Advanced Materials, in cooperation with the Kofkin Faculty of Engineering and the chemistry department.
How are artificial nanodiamonds produced?
Artificial nanodiamonds are produced by detonating explosives inside a closed chamber. Under these conditions, high temperature and pressure cause the carbon atoms found in explosives to fuse together. The nanodiamonds created in the process are small enough to penetrate tissue – and even cells – without inflicting harm.
Much like trucks that make deliveries, artificial diamonds can deliver various medications to intended targets, and their distance and location may be controlled due to their minute size. The approach to drug delivery using nanoparticles has already proven successful in previous research.
The nanodiamonds newly developed at BIU also have been proven to be effective antioxidants. This property ensures that particles penetrating the body are both safe and therapeutic, as their chemical properties allow them to be coated with medication prior to their insertion into the body.
The optical method developed by the team makes it possible for them to identify relative nanodiamond concentrations of particles in the different layers of skin (epidermis, dermis and fat) through safe and noninvasive sensing based on a blue wavelength laser. This is a unique finding in itself because red wavelength lasers are generally used in human medical exams and treatments.
To determine their location and concentration in the skin, patients are briefly exposed to the blue laser beam. An optical system creates a photograph-like 3D image through which optical changes in treated tissue can be extracted and compared to adjacent, untreated tissue using a specially created algorithm.
“This is a significant development in dermatology and in optical engineering,” said Prof. Dror Fixler, head of BIU’s Institute of Nanotechnology and Advanced Materials and a member of the research team. “It could open the door to developing drugs applied through the skin, alongside modern cosmetic preparations using advanced nanotechnology.”
Fixler’s research, assisted by researcher Channa Shapira and others, demonstrates the importance of optical innovation in clinical application.