Carboxymethylation of dextran for surface modification of magnetite nanoparticles

dc.contributor.advisor Torres-Lugo, Madeline Ayala-Rivera, Vanessa College of Engineering en_US
dc.contributor.committee Rinaldi, Carlos
dc.contributor.committee Carrero Martínez, Franklin
dc.contributor.department Department of Chemical Engineering en_US
dc.contributor.representative Lopez, Gustavo 2018-05-16T15:47:59Z 2018-05-16T15:47:59Z 2009
dc.description.abstract Magnetite nanoparticles are currently studied for biomedical applications such as MRI, drug delivery, and magnetic fluid hyperthermia (MHF). These applications require nanoparticles with a suitable coating which provides colloidal stability and improves the nanoparticle’s transport and interaction with biological tissues. Polysaccharides such as dextran have been used for this purpose due to their biocompatibility, low toxicity, and versatility for nanoparticle suspension in cell culture media. Functionalization of magnetite nanoparticles with dextran was performed by carbodiimide chemistry in which amine groups previously grafted onto the nanoparticle’s surface are reacted with carboxylic groups (-COOH) present in the dextran chain. These –COOH groups were introduced in the dextran chains by a carboxymethylation reaction, obtaining a carboxymethyl-dextran molecule (CMDx). The amount of –COOH groups per chain was controlled by different parameters such as reaction time, temperature, and sodium hydroxide and monochloroacetic acid (ClCH2COOH) concentrations. CMDx with different degrees of substitution were prepared and the nanoparticle’s surface charge and stability were studied using zeta potential measurements and dynamic light scattering. Results showed that decreasing the number of –COOH groups per dextran chain decrease the nanoparticle’s surface charge without affecting their colloidal stability. The nanoparticles coated with CMDx with 5, 23 and 38 –COOH groups per dextran chain were stable over the entire range of pH and NaCl concentration studied.
dc.description.graduationYear 2009 en_US
dc.description.sponsorship NSF NIRT en_US
dc.language.iso en en_US
dc.rights.holder (c) 2009 Vanessa Ayala Rivera en_US
dc.rights.license All rights reserved en_US
dc.subject Magnetite nanoparticles en_US
dc.subject Dextran en_US
dc.subject.lcsh Dextran en_US
dc.subject.lcsh Magnetite en_US
dc.title Carboxymethylation of dextran for surface modification of magnetite nanoparticles en_US
dc.type Thesis en_US
dspace.entity.type Publication Chemical Engineering en_US M.S. en_US
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