الفهرس 
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Abstract
Development of vehicles for drug delivery with high therapeutic efficacy and low undesirable side effects is considered a promising approach. Treatment by non-selective anticancer drugs is limited due to its toxicity to cancerous and healthy cells leading to undesirable side effects. To improve the therapeutic potential of bioactive agents, intracellular delivery should be facilitated and retention time inside the cell should be prolonged. In addition, harmful toxic effects on normal tissues should be limited. The unprotected drugs suffer from short in vivo half life time due to enzymatic environments and hostile immunological in the body. Targeting of nanocarriers can be achieved by extravasation and localization in abnormal tissues due to their high permeability and lack of lymphatic drainage. Triggered drug release have been attracted much attention using biological stimuli such as pH, temperature, redox and enzymes. Superparamagnetic iron oxide (SPIO NPs) have been used as carriers in biomedical applications due to their biocompatibility and biodegradability. SPIO have interesting potential biomedical applications in hyperthermia treatment, magnetic resonance imaging(MRI) and in anti-biofilms. Summary in Engli sh 115 In addition, SPIO NPs are considered as powerful contrasting agents due to their paramagnetic magnetization. Consequently, SPIO are useful in distinguishing between healthy and malignant cells. Furthermore, the irregular holes in the endothelial cells of cancer tissue allow the nanoparticles to penetrate the cancer tissues to perform deliver medication or labeling. Polyurethanes (PUs) are an exciting class of polymeric materials that exhibit a variety of properties that made them desirable for biomedical applications including drug delivery vehicles, antimicrobial surfaces, cardiac patches, tissue engineering scaffolds, coatings for breast implants and dressings for wound healing. Poly urethane-urea (PUU) has been extensively introduced in biomedical applications, due to their excellent physical and chemical properties, relatively good biocompatibility and biodegradability. The aim of the present thesis will be directed to prepare PUU/inorganic –SPIO nanocomposites and applications in drug delivery systems. The new materials have promising characteristics such as nontoxicity and biocompatibility. The thesis comprises of three chapters as follows: Chapter 1: This chapter introduced a general introduction about Nanoparticles, Magnetic nanoparticles, Functionalization of the SPIO NPs, metal oxides, Polymeric nanoparticles, Nanocomposite, Summary in Engli sh 116 Targeting therapy, Types of nanomaterials used in drug delivery systems. Then, this part was ended with literature survey on application of these materials in drug delivery system. Chapter 2: This chapter concerns with the experimental part. The chemicals and their resources were mentioned. The synthesis steps of SPIO NPs, PUU(400) NPS, SPIO(3)-PUU(400), Loading of NOR onto SPIO(1-6), nanocomposites (NOR@ SPIO- PUU), The silanization of SPIO by APTES, Loading NOR onto SPIO-NH2 NPs and NOR@(SPIO-NH2)-PUU, NOR and 5-FU Solutions, ZnO NPS, SPIO/ZnO NPS, Loading of 5-FU on SPIO/ZnO, 5- FU@(SPIO/ZnO)-PUU nanocomposite and Encapsulation of two drugs (NOR and 5-FU) in (SPIO/ZnO)-PUU nanocomposites were explained. Then, the techniques used for loading and release measurement and kinetics mathematical equations were discussed. After that the Instruments for characterization of nanocomposites were mentioned. Finally, the techniques used to evaluate antibacterial and anticancer activity were explained. Chapter 3: This chapter deals with the results which are summarized in the following parts.