The use of magnetic beads in IVD is not new. Recent developments –as the described in the next chapters- promise easier and better coating procedures where the orientation and the availability of the captured molecule can be controlled. However, most of the current applications are still using the classical surfaces.
Magnetic nanoparticles have proven particularly effective in chemotherapeutics applications. By combining the physical and chemical properties of more than one component material, nanoparticles can be designed that contain multiple functionalities, thereby dramatically increasing therapeutic efficacy. Recently, a research group out of University College Dublin in Ireland developed nanoparticles with distinct outer segments. The researchers coupled the properties of each of the segments to yield particles capable of performing diagnostic and therapeutic operations, inducing targeted cell death through multiple mechanisms.
Designing binding surfaces with optimal ligand (e.g. antibody, antigen or protein) functionality is required for ultra sensitive assays. However, classical solid phase chemistry approaches for conjugating or binding ligands to surfaces do not control the density or parking area of the ligand, nor do they provide control over ligand conformation and orientation.
KODE™ Technology is based on novel water-dispersible self-assembling molecules, called a function-spacer-lipids or KODE™ constructs (Figure 1) that are able to coat virtually any biological or non-biological surface with almost any biological or non-biological material [1-10]. The primary coating method of live cells, organisms, bacteria and viruses or solid surfaces (glass, metals, plastics, etc.) is achieved by simple contact with a solution containing one or more FSL KODE™ constructs. Upon contact the FSLs spontaneously and harmlessly create a stable and novel surface coating. Essentially the spontaneous self-assembling process is driven by the need of the constructs to “exclude water”. Because the constructs are able to bind to virtually any surface, be it hydrophobic or hydrophilic the mechanisms of action are multiple and complex and include hydrophobic interactions (via lipid tail), hydrophilic interactions (via the head group and spacer), micelle entrapment, encapsulation, bi/multi layer assembly, and other factors such as hydrogen bonding, van der Waals forces, electrostatic and ionic interactions and combinations of all the above on complex surfaces.
Bio-functionalized magnetic beads are widely used for capturing specific molecules or cells thanks to their super-paramagnetic properties. They are typically used for two main purposes in the Biotech field. They act as the solid phase for both separation processes such as purification of proteins/molecules and for in vitro diagnostics (IVD) reagents.
During the last weeks we have reviewed several aspects of biomagnetic cell sorting, a process which facilitates the quick and targeted removal of specific cells from a heterogeneous solution. Cell sorting is essential for a number of purposes, from technological to investigative and biomedical. By harnessing the properties of magnetic beads, biomagnetic separation (BMS) allows cells to be isolated for additional downstream applications, without adversely affecting their form or function.
Use of magnetic beads provides an efficient and innovative method of harnessing magnetic separation processes to non-magnetic, cellular targets of biological origin. When beads are attached, the ensemble of the cells and beads becomes a magnetizable object.
Coated magnetic beads are capable of interacting with and binding to a corresponding target within a sample. Binding specific biomarkers to the surface functional group present on the bead (e.g., streptavidin) ensures that the interaction is limited to specific cells. Recovery of material for further studies is greatly simplified when beads are concentrated from suspension, by means of an external magnet.
Nitrite and nitrate pollutants in soil and water pose significant health risks. The presence of these pollutants in drinking water can have serious consequences, including cancer, methemoglobinemia, and blue baby syndrome in newborns. Removal of these contaminants is essential to the maintenance of environmental and human health. Developing efficient strategies for removal, however, has proved challenging.
An article by Sepmag founder and CSO, Dr. Lluis M. Martinez, appears online this week in Genetic Engineering & Biotechnology News. The article addresses issues thatariseduring a biomagnetic separation application and offers critical suggestions for approaching a process. Of particular importance is an understanding of the inherent parameters of a separation.
