Type of Document Thesis Author Mohite, Virendra Author's Email Address firstname.lastname@example.org URN etd-11152004-184909 Title Self Controlled Magnetic Hyperthermia Degree Master of Science Department Mechanical Engineering, Department of Advisory Committee
Advisor Name Title Yousef Haik Committee Chair Ching-Jen Chen Committee Member Peter Kalu Committee Member Keywords
- Drug Delivery
Date of Defense 2004-10-28 Availability unrestricted AbstractHyperthermia has been gaining a lot of interest recently as a method for curing cancer especially as an adjunct to other modalities such as Radiotherapy and Chemotherapy. Hyperthermia can be effected by heating magnetic nanoparticles injected locally near the cancerous tissue that can be heated with the help of an external alternating magnetic field. Temperature rising above the 42ºC (315 K) may cause necrosis. The temperature can be controlled by using magnetic nanoparticles with a Curie temperature of 42ºC (315 K).
This study aims at finding the material for the magnetic nanoparticles with such desired magnetic properties. Various nanoparticles were synthesized using physical as well as chemical methods. The chemical methods are advantageous over physical methods because they offer a mixing of elements at molecular level and the synthesized particles are directly obtained in nanosize. The nanoparticles thus synthesized were checked for magnetic properties such as Curie temperature and magnetic saturation using SQUID and VSM. The constituents were estimated using XRD. Also, their morphology was observed using a TEM.
Amongst the various nanoparticles synthesized and one of the most promising particles for the self controlled magnetic hyperthermia application is the Gd substituted Zn Ferrite (with Gd, x = 0.02). These particles showed a Curie temperature of 314 K and also a high pyromagnetic co-efficient.
These particles are prepared to provide local heating at the tumor site. They can be used to assist in delivering chemotherapy drugs or radiosensitizing agents. Moreover, the polymer coating is thermosensitive such that its melting temperature is chosen to be equal to the Curie temperature of the particles (315 K). To make the nanoparticles avoid detection and subsequent elimination by the reticoendothelial system (RES) they were coated with polymers or proteins. The nanoparticles were coated with polymers such as polyethylene glycol (PEG), polyvinyl alcohol (PVA), ethyl cellulose and also with a protein - human serum albumin (HSA). The morphology of these coated nanoaprticles were observed using a TEM.
Experiments were conducted to confirm that the magnetic nanoparticles achieve sufficient heating upto 42°C when subjected to alternating magnetic field. Also it was experimentally confirmed that the polymer/protein coatings were broken when heated to 42°C.
This study concludes with the suggestion of possibilities for making the hyperthermia treatment feasible and more efficient such as by combining it with drug delivery.
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