Current Pharmaceutical Biotechnology - Volume 5, Issue 6, 2004

Molecular and cellular imaging is a relatively young field that is rapidly changing our approach towards understanding and solving problems in biology and medicine. Among the different imaging modalities, MR imaging offers both whole body penetration and high spatial and temporal resolution. Now that the hardware necessary to perform MR imaging in sufficient detail can be found in many places across the world, it Read More

Over the past decade MR (magnetic resonance) imaging has emerged as one of the major modalities for noninvasive functional imaging. Recent advances in the development of targeted MR contrast agents have added significantly to the capabilities of MR imaging. In particular, the use of targeted contrast agents to report on the expression of cell surface receptors, combined with the functional capabilities of MR imaging, Read More

Molecular biology and genomic sciences are revealing the early biological signatures for many diseases. In response, the Molecular Imaging community is rapidly developing contrast agents to visualize the nascent pathological changes and to concomitantly deliver treatment directly to the site of disease. The evaluation, development and use of these new agents require a complementary understanding of contrast che Read More

The low sensitivity is the major disadvantage of MRI as compared to PET. Therefore, amplification strategies are necessary for specific pathway labeling. This survey is aimed at exploring different routes to the entrapment of Gd(III) chelates in various type of cells at amounts sufficiently large to allow MRI visualization. Namely, the obtained results have been summarized in terms of internalization via i) pinocytosis; ii) phagocyto Read More

The relative non-specificity of the first generation MR contrast agents has meant that a new approach to their design is required. This review focuses on a new class of more specific or functional agents. These are the so-called “activated”, “smart” or “responsive” contrast agents. The relaxivity of an activated contrast agent is responsive to (or can be modulated by) a particular in vivo stimulus such as a change in biolo Read More

Manganese is an essential metal that participates as a co-factor in a number of critical biological functions such as electron transport, detoxification of free radicals, and synthesis of neurotransmitters. Like other heavy metals, high concentrations of manganese are toxic. For example, chronic overexposure to manganese leads to movement disorders. In order to maintain this balance between being an essential participant in e Read More

Paramagnetic metals can induce T1 shortening by interaction with free water molecules. Two metal ions, Gadolinium and Manganese, are currently available for human use. Gadolinium-based MRI contrast agents (CAs) can operate using a ∼100-fold lower concentration of Gadolinium ions in comparison to the necessary concentration of Iodine atoms employed in CT imaging in the tissues. Therefore, numerous macromolecul Read More

Organ transplantation is the generally preferred medical procedure of treatment for patients with end-stage organ failure. The immunological reaction of rejection is a major cause of functional failure in transplant patients. The current “gold standard” for detecting or confirming graft rejection following solid organ transplantation requires biopsy samples in order to detect immune cell (e.g., T-cells, macrophages, etc.) i Read More

Given the remarkable progress that has recently been obtained in animal studies, the clinical use of stem and progenitor cells to correct or replace defective cell populations may soon become a reality. In order to develop effective cell therapies, the location and distribution of these cells must be determined in a non-invasive manner. Magnetic resonance (MR) tracking of magnetically labeled cells following transplantation or tra Read More