Functional Materials Based on Surface Modification of Carbon Nanotubes for Biomedical and Environmental Applications

Handle URI:
http://hdl.handle.net/10754/552903
Title:
Functional Materials Based on Surface Modification of Carbon Nanotubes for Biomedical and Environmental Applications
Authors:
Mashat, Afnan
Abstract:
Since the discovery of carbon nanotubes (CNTs), they have gained much interest in many science and engineering fields. The modification of CNTs by introducing different functional groups to their surface is important for CNTs to be tailored to fit the need of specific applications. This dissertation presents several CNT-based systems that can provide biomedical and environmental advantages. In this research, polyethylenimine (PEI) and polyvinyl alcohol (PVA) were used to coat CNTs through hydrogen bonding. The release of doxorubicin (DOX, an anticancer drug) from this system was controlled by temperature. This system represents a promising method for incorporating stimuli triggered polymer-gated CNTs in controlled release applications. To create an acid responsive system CNTs were coated with 1,2-Distearoyl-snglycero- 3-Phosphoethanolamine-N-[Amino(Polyethylene glycol)2000]-(PE-PEG) and Poly(acrylic acid) modified dioleoy lphosphatidyl-ethanolamine (PE-PAA). An acidlabile linker was used to cross-link PAA, forming ALP@CNTs, thus making the system acid sensitive. The release of DOX from ALP@CNTs was found to be higher in an acidic environment. Moreover, near infrared (NIR) light was used to enhance the release of DOX from ALP@CNTs. A CNT-based membrane with controlled diffusion was prepared in the next study. CNTs were used as a component of a cellulose/gel membrane due to their optical property, which allows them to convert NIR light into heat. Poly(Nisopropylacrylamide) (PNIPAm) was used due to its thermo-sensitivity. The properties of both the CNTs and PNIPAm’s were used to control the diffusion of the cargo from the system, under the influence of NIR. CNTs were also used to fabricate an antibacterial agent, for which they were coated with polydopamine (PDA) and decorated with silver particles (Ag). Galactose (Gal) terminated with thiol groups conjugated with the above system was used to strengthen the bacterial targeting ability. The antibacterial activity of Ag/Gal@PDA@CNTs was examined on Escherichia coli. NIR was used to enhance the antibacterial activity of Ag/Gal@PDA@CNTs. Finally, CNTs were used as a support for methyl orange (MO) and palladium catalysts (Pd). MO was used due to its ability to enhance the catalyst activity. Pd@CNTs composites were used to test the reduction rate of nitrite with and without the addition MO. The results showed that over repeated cycles of nitrite reduction, the activity enhancement was lost. In summary, CNTs are promising building blocks for preparation of smart and stimuli responsive systems that have potential for a wide range of applications. The methods presented are simple and can be scaled up for industrial processing purposes.
Advisors:
Khashab, Niveen M. ( 0000-0003-2728-0666 )
Committee Member:
Saikaly, Pascal E.; Takanabe, Kazuhiro ( 0000-0001-5374-9451 ) ; Amy, Gary; Shamy, Magdy
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Program:
Environmental Science and Engineering
Issue Date:
May-2015
Type:
Dissertation
Appears in Collections:
Environmental Science and Engineering Program; Dissertations; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.advisorKhashab, Niveen M.en
dc.contributor.authorMashat, Afnanen
dc.date.accessioned2015-05-14T18:46:58Zen
dc.date.available2015-05-14T18:46:58Zen
dc.date.issued2015-05en
dc.identifier.urihttp://hdl.handle.net/10754/552903en
dc.description.abstractSince the discovery of carbon nanotubes (CNTs), they have gained much interest in many science and engineering fields. The modification of CNTs by introducing different functional groups to their surface is important for CNTs to be tailored to fit the need of specific applications. This dissertation presents several CNT-based systems that can provide biomedical and environmental advantages. In this research, polyethylenimine (PEI) and polyvinyl alcohol (PVA) were used to coat CNTs through hydrogen bonding. The release of doxorubicin (DOX, an anticancer drug) from this system was controlled by temperature. This system represents a promising method for incorporating stimuli triggered polymer-gated CNTs in controlled release applications. To create an acid responsive system CNTs were coated with 1,2-Distearoyl-snglycero- 3-Phosphoethanolamine-N-[Amino(Polyethylene glycol)2000]-(PE-PEG) and Poly(acrylic acid) modified dioleoy lphosphatidyl-ethanolamine (PE-PAA). An acidlabile linker was used to cross-link PAA, forming ALP@CNTs, thus making the system acid sensitive. The release of DOX from ALP@CNTs was found to be higher in an acidic environment. Moreover, near infrared (NIR) light was used to enhance the release of DOX from ALP@CNTs. A CNT-based membrane with controlled diffusion was prepared in the next study. CNTs were used as a component of a cellulose/gel membrane due to their optical property, which allows them to convert NIR light into heat. Poly(Nisopropylacrylamide) (PNIPAm) was used due to its thermo-sensitivity. The properties of both the CNTs and PNIPAm’s were used to control the diffusion of the cargo from the system, under the influence of NIR. CNTs were also used to fabricate an antibacterial agent, for which they were coated with polydopamine (PDA) and decorated with silver particles (Ag). Galactose (Gal) terminated with thiol groups conjugated with the above system was used to strengthen the bacterial targeting ability. The antibacterial activity of Ag/Gal@PDA@CNTs was examined on Escherichia coli. NIR was used to enhance the antibacterial activity of Ag/Gal@PDA@CNTs. Finally, CNTs were used as a support for methyl orange (MO) and palladium catalysts (Pd). MO was used due to its ability to enhance the catalyst activity. Pd@CNTs composites were used to test the reduction rate of nitrite with and without the addition MO. The results showed that over repeated cycles of nitrite reduction, the activity enhancement was lost. In summary, CNTs are promising building blocks for preparation of smart and stimuli responsive systems that have potential for a wide range of applications. The methods presented are simple and can be scaled up for industrial processing purposes.en
dc.language.isoenen
dc.subjectCarbon Nanotubesen
dc.subjectSurface Modificationen
dc.subjectDrug Deliveryen
dc.subjectNear Infrareden
dc.titleFunctional Materials Based on Surface Modification of Carbon Nanotubes for Biomedical and Environmental Applicationsen
dc.typeDissertationen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberSaikaly, Pascal E.en
dc.contributor.committeememberTakanabe, Kazuhiroen
dc.contributor.committeememberAmy, Garyen
dc.contributor.committeememberShamy, Magdyen
thesis.degree.disciplineEnvironmental Science and Engineeringen
thesis.degree.nameDoctor of Philosophyen
dc.person.id101800en
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