Nanomaterials have long been implicated as the potential capsules in which we will deliver the drugs of the future. While familar nanomaterials such as nanotubes and fullerenes have been studied extensively and show promise for this application, their biocompatibility remains i
n question. Detonation nanodiamonds (NDs) are highly structured diamond-based materials that can form in sizes as small as 2nm. These NDs are very appealing for future drug delivery applications due to the ease of their production (literally through TNT detonations), stability, and their high ordered structure. Most importantly, this ordered structure appears to make these NDs less harmful to cells and less likely to cause inflammation.
A study from Dean Ho's lab at Northwestern recently used these ND structures to deliver chemotherapeutic drugs to murine macrophage cells and human colon cancer cells. The group was able to cluster ND particles into 50-100nm clusters which bound to the cancer drug, DOX, upon the addition of salt. This binding is typically stable until salt concentration lowers, at which point the drug can be released. Moreover, the high surface area on the 1000's of tiny NDs that compose the delivery structure allows a high amount of drug to be delivered by this mechanism.When the group tested DOX-loaded NDs on murine and human cells, they found that they could control the release of DOX to occur at the target sites. Morover, the group found that there was no imflammation in cells caused by presence of the ND's, and upon drug release the clusters breakdown into tiny ND components that appear to be harmless to the body. The stability of these NDs also allows for significant functionalization, which is essentially chemistry performed on the surface of the molecules, and can be used to facilitate targeting to the right areas of the body. While work on these NDs for drug delivery is still in its early stages, NDs hold promise in drug delivery because of their stability, safety, and ease of functionalization.(FIGURE from CNN.com)
A monomer is a small chemical building block that can chemically bond with other monomers to form more complex structures called polymers (i.e. A-A-A-A-A-A). While many polymers consist of repeats of the same monomer, some called copolymers are the result of two or more different monomers linking together in chains (i.e. A-B-A-A-B-B). Block copolymers are examples of copolymers that can be joined to eachother to form a meta-structure with multiple domains (see figure). A recent paper published in ACS Nano has demonstrated the use of block copolymers in a nanofilm for coating medical devices.
In this paper, Dean Ho, et al. add a polymethyloxazoline-polydimethylsiloxan- polymethyloxazoline (PMOXA-PDMS-PMOXA) copolymer with dexamethazone - together referred to as PolyDex - to an implant using a method called Langmuir-Blodgett deposition. The PolyDex was able to "cloak" the implant as it was found to be necessary and sufficient to prevent immune response from cells in normal mice after the implantation of two polyethylene disks.
This PolyDex nanofilm can contribute significantly in the medical device field as devices become smaller and more fragile. The ability of these nanofilms to prevent the accumulation of inflammatory cells may help protect implants from post-implantation damage and increase the mortality of implants in the future. Moreover, this coating may aid in the reduction of overall inflammation of the implant site that may reduce further complications that occur after surgeries. The small thickness of these films at 4 nanometers per layer will make this film extremely versitile as it will allow manufacturers to apply it to the smallest of implants.
While these nanofilms are still very early in development, they show great promise in medical devices, for which inflammation is an all too common issue.
Overview
Oxonica is a publicly traded international nanotechnology company with subdivisions in energy, healthcare, materials, and security. Oxonica was founded in 1998 by Prof. Peter Dobson and Dr. Gareth Wakefield out of the Universit of Oxford. The company was founded around a core set of patents e
ncompassing nanoparticles and coatings that Oxonica sought to use in diagnostics, fuel additives, metal coatings, and topical treatments. Oxonica has U.S. offices in Mountain View, CA for its healthcare and security divisions and reported a gross profit of £6M from £10.3M revenue in 2006.
www.Oxonica.com
Products
Oxonica's commercialized products are Envirox™ and Optisol™ from the energy and materials divisions, respectively, and the Nanoplex™ system is currently under development in the healthcare division.
Envirox™- A fuel born catalyst designed as an additive in diesel engines to reduce fuel consumption and emission. Technologically, Envirox™ is engineered from cerium oxide to make it active enough to be added at 5 mg/L of diesel. The catalyst acts by lowering the combustion temperature of carbon in the combustion chamber and improving the oxidation of unburnt fuel and carbon deposits. Refer to this pdf for more info.
Optisol™- A UV absorber used as an additive in sun-care and anti-aging products. Optisol™ is produced by incorporating manganese ions in the the major titanium dioxide component of the product. This provides a major competitive advantage, as the manganese ions cause Optisol™ to absorb free radicals and prevent them from harming the body.
Nanoplex™- Oxonica's acquisition of Nanoplex, Inc. in 2006 provided the company with Nanoplex™ system, which is a cost effective system capable of performing high throughput detection of multiple particles within human samples. The system uses gold nanoparticles, which are coated with Raman-activated dye and SiO2, and conjugated with antibodies that recognize targets within a tissue or blood sample. Through a process called Raman Scattering, the targets can be detected in stereotypical readouts that are analyzed by the physician. The major advantage of this system is its speed (under 30 min) and its ability to detect multiple targets in a single sample.
News
12.13.2007- Oxonica's security division completes technological milestones, prompting the business to receive $275K in follow-on orders from a total of $1.16M promised upon further completion of milestones.
9.27.2007- Oxonica signs a follow-on R&D agreement with Becton Dickinson, a major pharma company interested in the Nanoplex™ system. Under the terms of the agreement, BD will fund the development of Nanoplex™ to evaluate its use in clinical situations.
10.19.2006- Oxonica is named by Lux Research to be one of four nanotechnology startups of the greatest value to corporate partners.
7.6.2006- Oxonica's platform detection technology wins Nanotech Briefs Nano 50 Award.
(FIGURE from Nanotech-now.com)
