Application of magnetic fluids in medicine and biotechnology

Several advancements have been made in the last two decades for targeting d rugs to a specific area in the human body. Liposomes, resealed erythrocyte ghost preparations, antibody mediated drug targeting to specific cancer cel ls have become popular means of drug targeting. However all these methods a re associated with several practical problems and involve tedious developme nt stages. In the past few years, this group has been involved in developin g the usage of magnetic particles as suitable carriers for delivering drugs . This method of drug delivery ensures site-specific action as well as, eas y to develop and use technology. Clot lytic agents like streptokinase, urok inase or tissue plasminogen activator are traditionally used for treating t hrombosis, One of the major problems associated with this treatment is its nonspecific and undirected thrombolytic activity. Using magnetic fluids, as carriers for above enzymes would ensure specificity of action, reduction i n amount and time of action of the drug with no side effects. This line of action could be used in treating peripheral and coronary occlusive diseases . The process of hysteresis can be utilized to develop heat in magnetic flu ids and this can be used to induce hyperthermia to treat tissues/cells, esp ecially in oncology. This, in addition to delivering anticancer drugs via m agnetic particles could prove to be an excellent line of treatment for canc er chemotherapy. Phase I clinical trials using reversibly bound anticancer drug epirubicin were done, and it was found that the ferrofluid could be su ccessfully directed to the tumors in about one-half of the patients Present studies have shown that proteins can be bound to magnetic particles withou t losing their biological properties. Some of the enzymes immobilized by us have been found to retain almost 90% of their activity. The same principle could be used to deliver anticancer and thrombolytic drugs, which have bee n entrapped in protein microspheres, These can be targeted to tumor cells b y an external magnetic field so that it can deliver the drug slowly and in the required amount at the same time avoiding side effects associated with these drugs. The applications of magnetic fluids in other fields are also m anifold. Magnetic for isolating mRNA are quicker and more efficient, and th ey avoid organic solvents and the need for a precipitation step. Magnetic b eads linked to high affinity capture antibodies have been widely accepted a s separation techniques of specific target ligands or particles such as bac teria or leukocytes from complex mixtures, such as bone marrow, blood and o ther body fluids. Detection of contaminating microorganisms like staphyloco ccus sp. In milk using a magnetic based ELISA (Enzyme Linked Immunosorbent Assay) has been developed. It is also proposed to use this technology to im mobilize polymixin B antibiotic for the treatment of endotoxic shock. The e xtreme toxicity of this antibiotic could be avoided using dialysis to remov e the magnetically bound antibiotic, from systematic circulation, after its action. could be avoided using dialysis to remove the mag Similarly using magnetically immobilized antifungal agent amphoterecin, for systemic applic ation, could reduce toxicity of this antifungal agent. Investigating the us e of magnetically immobilized Horseshoe crab protein for combating endotoxi c shock could also prove to be an effective line of treatment. Using magnet ic particles as such or erythrocyte ghost preparations of the same could be used as an opaque medium in angiography and radiography techniques. In add ition to this, using magnetically immobilized microorganisms for wastewater treatment is an extremely cost effective technology.