Novel Fabrication Strategies for Multifunctional Hydrogel Microparticles.
Lewis, Chrisitna.
2017-04-18T13:59:02.980Z
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Abstract: Three fabrication strategies for poly (ethylene glycol) (PEG) -based microparticles and their utility for exploiting the advantages of viral nanotemplates and DNA oligonucleotides are presented in this dissertation: 1. Nucleic Acid Hybridization Assembly of Viral Nanotemplates on Microparticles A flow lithography technique known as stop-flow lithography (SFL) was used to fabricate microp... read morearticles with discrete regions for sample identification and patterned assembly of functionalized tobacco mosaic virus (TMV) nanotemplates. TMV nanotemplates were programmed with linker DNA, complementary to the probe DNA in the assembly region of the microparticles. The hybridization-based assembly yielded specific, programmable, and spatially selective assembly of TMV nanotemplates on encoded hydrogel microparticles and demonstrates a novel high throughput route to create multiplexed and multifunctional viral-synthetic hybrid microentities. 2. Microparticles Containing Functionalized Viral Nanotemplates Functionalized viral assemblies were uniformly distributed throughout hydrogel microparticles by direct embedding with a microfluidic flow-focusing device and UV photopolymerization. Fluorescence and confocal microscopy images showed uniform distribution of the TMV nanotemplates. Microparticles containing TMV-templated palladium (Pd) nanoparticles exhibited catalytic activity for the dichromate reduction reaction. The results reveal that microparticles provide a stable and simple-to-handle carrier for TMV nanotemplates and address a critical challenge of 3D assembly of functionalized viral hybrid nanomaterials. 3. DNA-Conjugated Microparticles via Replica Molding (RM) DNA-conjugated microparticles were fabricated using a soft-lithographic batch processing-based technique, known as RM. A humidity controlled environment was found to minimize the negative effects of rapid evaporation and ensure uniformity across batch fabricated microparticles. It was also found that PEG-diacrylate concentration effects hybridization and target DNA penetration depth. Additionally, the effects of probe DNA and photoinitiator concentration on target DNA hybridization and particle formation were examined. Finally, sequence-specificity and responsiveness down to single nanomolar concentrations was determined. The results demonstrate a simple, robust, and scalable batch procedure for manufacturing highly uniform hybridization assay particles in a well-controlled manner. Additionally, this work illustrates a novel batch fabrication technique, which offers advantages over the traditional, continuous (microfluidic) fabrication methods for DNA-conjugated microparticles. Together, these results identify multiple simple and well-controlled fabrication strategies for PEG-based, functional hydrogel microparticles, which contribute to the advancement and application of functional biomaterials.
Thesis (Ph.D.)--Tufts University, 2011.
Submitted to the Dept. of Chemical and Biological Engineering.
Advisor: Hyunmin Yi.
Committee: Daniel Ryder, Da vid Kaplan, and Patrick Doyle.
Keywords: Chemical Engineering, Chemistry, and Nanotechnology.read less - ID:
- n009wd59j
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