Quantum dot-based diabetic foot mapping for diagnosing osteomyelitis and Charcot neuroarthropathy

The location of osteomyelitis is very important in Charcot neuroarthropathy (CN), especially when a physician is considering amputation of the affected extremity. In diabetic CN, the presence of osteomyelitis is likely. Thus, to identify the infected tissue that needs to be removed, the specific area of infection must be correctly identified. Both CN and osteomyelitis have high mortality rates, but osteomyelitis is more life threatening and needs aggressive treatment. We propose a QD-based method for distinguishing CN with sterile inflammation from osteomyelitis that does not require multiple and frequent imaging modalities. The method utilizes two different colored QDs (i.e., red and green). The red QD is attached to a UBI, an antimicrobial peptide, which attaches to bacteria, enabling their detection. The green QD is attached to MDP, which accumulates in areas of inflammation. When these QDs are injected intravenously at the same time, the red QD-UBI accumulates in infected areas and attaches to bacteria, and the green QD-MDP accumulates both in areas with sterile inflammation and infected areas. The accumulation of only green QDs in the suspect extremity signifies a sterile inflammation process (CN). However, the accumulation of both the red and green QDs signify infectious and inflammation processes (i.e., osteomyelitis or a soft tissue infection, depending on the location). In the latter case, the treatment needs to be more intensive, with even amputation considered.