Application of magnetic fluids in medicine and biotechnology

Several advancements have been made in the las t two decades for targeting dru gs to a speci fi c area in the human bod y. Liposomes, resealed erythrocyte ghost preparations. ant ibody mediated drug targeting to specific cancer cell s have become popular means of drug targeting. However all these methods are associated with several prac ti cal problems and involve ted ious dcvelopmen t stages. In the past few years. th is group has been invol ved in developing the usage of magneti c particlcs as suitable carriers for de li vering drugs. This method of drug deli very ensures site-specific ac ti on as well as easy to develop and use tech nology. Clot lytic agcnts like streptokinasc. urokinase or ti ssue plasminogen acti vator are traditiona ll y used for treating thrombosis. One of the major problems associatcd with this treatment is its nonspecific and undirected thrombolytic acti vity. Using magneti c fluid s. as carriers for above enzymes woul d cnsure speci ficit y of action . reduction in amount and time of action of the drug with no side effects. Thi s line of acti on could be used in treat ing peripheral and coronary occ lu sive discases. The process of hysteres is can be ut ili zcd to develop heat in magnetic tluids and thi s can be used to inducc hypert hermia to treat ti ssues/cell s, especia ll y in oncology . This, in addition to delivering anticancer drugs via magneti c parti cles could prove to bc an excell en t line of treatment for cancer chcmotherapy. Ph ase I clin ica l tri als using reversibl y bound an ti cancer drug ep irubi cin werc donc. and it was found that the ferrotluid cou ld be successfull y directed to thc tumors in about one-half of the patient s. Present studies have show n that proteins can be bound to magnetic particles wit hout losing their biological properti es. Somc of the enzymes immobilizcd by us ha ve bccn found to retain almost 90% of their activi ty. Thc samc principle could be used to de li ver anti cancer and th rombolyti c drugs. whi ch havc bccn cntrappcd in prot cin mi crosphcres . Thesc can bc targcted to tumor ccll s by an cx tcrnal magnctic fi eld so tha~...( an dcli vcr the drug slowly and in the requircd amount at the same timc avoidi ng side effccts associated wit h these drugs. e app lications of magnet ic fluid s in other fi elds arc also manifold. Magnctic for isolating mRNA are quickcr and morc effiCient , and they avoid organi c solvcnts and the need for a precipitMion step. Magncti c beads linked to hi gh affinit y capture antibod ies have becn widely acceptcd as scparation techniqucs of specific target ligands or particles such as bactcri a or leukocytes from complcx mixtures. such as bonc marrow. blood and other body flui ds. Detcc ti on of cont amin at ing mi croorgan isms likc .\'!al'hvlococclI .\· Sf' . In milk using a magnctic bascd ELISA (Enzy me Linkcd Immllnosnrbcnt Assay) has been developed. It is also proposcd to use thi s tcchnology to immobilizc polymixin B anti biot ic for the treatment of endotoxic shock. The cx tremc toxicity of thi s antibiotic could be avoided usi ng dialysis to rcmovc the magncti ca ll y bound antib iotic, from systcmatic ci rculatiun. aftcr its action . Simi larly using magneti call y immobili zed ant ifungal agent amphotcreci n. for systcmic appli cati on. cOlild reducc tox icity of thi s ant ifungal agcnt. In vcs ti gati ng thc usc of magnctica ll y immob ili zed Horseshoc crab protein for combating endotoxi c shock could al so prove to be an cffective line of treatmcnt. Using magnetic particlcs as such or erythrocyte ghost preparations of the same could bc uscd as an opaq uc medi um in angiography and radiography techniques. In add ition to thi s. using magnetica ll y immobili zecimicroorganisms for wastewater trcatment is an ex trcmely cost effecti ve teChnOl Ogy.)