Diagnostics as a means for successful prevention and efficient treatment of diseases play a key role in medicine. The advantage of nanotechnology based diagnostics lies in its potentially higher sensitivity and selectivity as compared to classical methods. Molecular recognition, i.e. the modification of nano-particle surfaces with chemical recognition groups (markers) allows identifying complementary groups on cell surfaces which are indicative of specific tissue or diseases. Magnetic Resonance Imaging (MRI) , Computer Tomography (CT) and Single Photon Emission CT (SPECT) are molecular imaging techniques to display high resolution images of in vivo tissues. The effectiveness of these methods relies on the availability of tracers that are specific to the diagnostic question pursued.
Most common contrast agents work based on X-ray attenuation and Magnetic Resonance Induction (MRI) signal enhancement:
- Iodine and barium are the most common types of contrast medium for enhancing x-ray-based imaging methods.
- Gadolinium is used in magnetic resonance imaging as a MRI contrast agent. With the exception of inorganic compounds, materials developed for MRI application are mostly smaller than nano-particles. MRIs applications area and resolution power may be significantly improved by new nanosized contrast agents. An example of MRI contrast agents are Gadolinium-based dendrimers which can be effective at a very low concentration and target different organs because of difference in their size.
NanoGlys™ and Contrast Agents
We are developing Iodine based X-Ray attenuators that benefit from the properties of the nano-carrier in terms of vasculature permeability and are more stable and less toxic.
Similar to Gd-based dendrimers NanoGlys™ MRI contrast agents can be designed for specific diagnostic applications. Gd-complexes attached to NanoGlys™ will accumulate in cancer tissue and get absorbed by cancer cells. Tissue or disease specific tracers (markers) can be attached to the surface of the nano-particle and enhance target specific imaging.
NanoGlys™ and Fluorescence/NIR Imaging Agents
A recent development in biomedical imaging is the non-invasive in vivo diagnosis using fluorescence. Fundamental to this development is the discovery of bio-compatible, specific fluorescent probes and proteins and the development of highly sensitive imaging technologies for in vivo fluorescent detection. Reflectance fluorescence imaging and fluorescence-mediated molecular tomography (FMT) are the two most common approaches currently used for imaging fluorescent probes in deep tissues. Future NIRF imaging agents that consist of bright fluorescent dyes conjugated to NanoGlys™ moieties promise enhanced molecular imaging and image-guided surgery.