Nanoparticulate Scrub to Remove Biofilm Bacteria from the Skin/Implant Interface in Osseointegrated Implants
Abstract
Injuries to the extremities (arms and legs) have become the most common types of injuries experienced by U.S. military personnel in recent conflicts. When long bones of the extremities are fractured, every effort is made to try to preserve and reconstruct the injured limb. Unfortunately, major injuries to the extremities can frequently result in amputation, with severe resulting difficulties for the patients so affected, especially if they are subject to “high” amputations in the thigh or upper arm. Although regular prosthetic devices can serve the needs for some such patients, many others benefit from surgical reconstruction after amputation with osseointegrated implants (OIs), that is, implants placed directly into the bony stump of the amputated limb such that a prosthetic can then be more firmly attached. OIs offer significant advantages to patients, but because the OI protrudes through the skin, it is frequently subject to infection, especially from the bacteria that typically reside on skin surfaces. These infections can be recurrent, requiring repeated treatment with antibiotics, and in severe cases can lead to infection of the deep bony tissues (osteomyelitis) and the removal of the implant. Like other orthopaedic devices, it has recently been recognized that bacteria can attach to OIs in the form of biofilms, that is, communities of bacteria that are difficult to eradicate short of removing the implant altogether. Bacterial biofilms are up to a thousand times more resistant to conventional antibiotics and difficult to diagnose and culture with normal microbiological techniques. A better strategy to deal with such biofilm bacteria and biofilm infections is to prevent them from taking root in the first place. The same strategy is equally applicable to the prevention of infection in the setting of an OI. We now propose a new way to accomplish just this task using a novel biomaterial developed by Novaflux Inc.: Nanoscrub. Nanoscrub is a newly developed nanostructured fluid that functions like a flowing lattice of material over a surface. Bacteria and biofilm that are residing on the surface become entangled in the molecular lattice of the Nanoscrub and are physically removed, effectively sterilizing the surface. The unique chemical and physical properties that enable this application are intrinsic to the Nanoscrub material formulation, which is comprised of components that the Food and Drug Administration have already acknowledged are GRAS: Generally Recognized as Safe. Thus, Nanoscrub presents no risk to the patient. The advent of Nanoscrub allows a new way to approach controlling biofilm infection around OIs: by routinely physically removing the bacteria altogether. This is a radical departure from the use of conventional disinfecting agents such as chlorhexidine or iodine, which aim to kill or inhibit bacteria in place but do not physically displace them. Nanoscrub has already been shown to essentially eliminate all biofilm bacteria from both inorganic surfaces (e.g., endoscope channel) and organic surface (pig skin). We anticipate it will be equally effective in completely removing pathogenic bacteria from human skin and OI metallic components, thereby rendering the likelihood of invasive infection nil. We envision that patients with OIs can regularly (e.g., daily) and easily apply Nanoscrub to their implant sites (the skin/implant interface) and keep these sites biofilm-free and therefore infection-free. In this submission, we propose to demonstrate that Nanoscrub will abolish biofilms of three different species of Gram-positive and -negative bacteria from skin surface (using pig skin as an ex vivo model since it is most similar to human skin). We will similarly demonstrate that Nanoscrub will eliminate biofilm from metal surfaces such as those found in OIs. We will then confirm its efficacy in a rabbit model of trans-cutaneous implant infection meant to recapitulate the core elements of a
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010658
Entities
People
- Sandeep Kathju
Organizations
- United States Army