FFC NMR relaxometry is particularly useful in pharmaceutical and healthcare applications, where it has been used to study the conformational properties of aqueous solutions (formulations), protein dynamics and is especially important in studies for the development of contrast agents for clinical MR Imaging.
It is important to know the hydration states of ingredients in pharmaceutical formulations to understand, the physical and chemical properties and behaviour of the components as well as the final water content of an end-product medicine, which may affect the shelf life.
The figure shows NMRD profiles of aqueous solutions of Hyaluronic Acid (HA) studied at three concentrations in the range 10 to 25 mg/ml. From this data it could be confirmed that three different hydration layers surround hyaluronan irrespective of HA concentration.
A. Prusova, P. Conte, J. Kucerik, G. Alonzo Analytical and Bioanalytical Chemistry 397: 7 (2010) 3023-28
MRI contrast agents
The study of relaxivity is important in the design of effective new MRI contrast agents. The increased use of 3 Tesla clinical MRI scanners in hospitals means that understanding relaxivity of a contrast agent at 3T is becoming an important requirement. With an integrated system for high field FFC NMR relaxometry (see High Field Relaxometry) it is now possible to carry out full relaxivity profiling for contrast agents.
The figure shows the NMRD profiles of aqueous solutions of three Gadolinium-based contrast agents. These have a characteristic peak in the NMRD profile at around 60 MHz. The contrast agent corresponding to the blue curve has a higher relaxivity than the other two, which is a desired property when designing new contrast agents.
Liposomes have been studied extensively during the last decade for their potential as carriers for drugs, such as chemotherapeutic agents.
The NMRD profiles shown in the figure demonstrate that when a paramagnetic Gadolinium complex, is incorporated into a liposome, its relaxivity is much higher than another analogous clinically approved Gadolinium complex over the entire range of magnetic fields investigated. Higher relaxivity of contrast agents is a desired property.
Proteins are important biomolecules with many functions in nature. The study of the behaviour of proteins is highly important in the pharmaceutical and biotechnology industries as many medicines act on protein receptors and indeed engineered proteins are frequently active ingredients in a new medicine. The function of proteins as well as other natural macromolecules present in cells and their membranes is often critically dependent upon their movement (dynamics).
The two figures show:
a) Protein aggregation can be detected via rotational diffusion: information on how self-association of Bovine pancreatic trypsin inhibitor changes at different concentrations of saline solution can be obtained from these NMRD profiles.
M. Gottschalk, K. Venu, B. Halle, Biophysical Journal 84 (2003) 3941-3958
b) The NMRD profiles can provide information on the cross-link formation, and thus immobilization effects, of the protein Bovine Serum Albumin (BSA) at different concentrations.
G. Diakova, Y. A. Goddard, J.P. Korb, R. G. Bryant Biophysical Journal 98 (2010) 138–146
Biochemical research: gelation of biomolecules
FFC NMR relaxometry can be used for many studies in biochemical research, such as the physical states of complex mixtures.
The figure shows the gel state (gelation process) of a methoxyl pectin solution changes with the concentration of calcium chloride.
M. Dobies, M. Kozak and S. Jurga Solid State Nuclear Magnetic Resonance 25 (2004) 188–193