Date of Award

1-1-2009

Document Type

Campus Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

Qian Wang

Abstract

Proteins and bionanoparticles (BNPs) are the key building blocks of all biological matters. The study of their self-assembly behavior with various polymers is of increasing interest for development of functional materials. Compared to inorganic or organic nanoparticles, BNPs are truly monodisperse and can be modified in a well defined manner. Both of these attributes are critical for the quantitative understanding and control the self-assembly structure. Through the assembly of BNPs to form the BNPs-based materials are of great interest.

Among all BNPs-based materials, BNPs-polymer core-shell structures with the polymer as the core and BNPs as the shell can find poteinal applications such as drug delivery and cell binding. However, no methods to form the BNPs-polymer core-shell structures have been reported.

In chapter one, we will discuss the co-assembly method based on non-covalent interactions of spherical BNPs such as CPMV, TYMV, ferritin, and P22 with polymers including poly(4-vinylpyridine) (P4VP) and poly(Ε-caprolactone)-block-poly(2-vinyl pyridine) (PCL-b-P2VP) to obtain core-shell structures. The structures have very good coverage of BNPs on the surface of polymeric spheres as characterized by transmission electron microscopy (TEM) and field emission electron microscopy (FESEM) analyses. The solvent composition has a profound effect on the size and morphology of core-shell structures. The assembly process can be controlled by varying the solvent pH values. Moreover, one of spherical BNPs, TYMV, can form the closed-packing on the surface of polymer, characterized by FESEM and SAXS.

In chapter two, we will discuss the co-assembly of rod-like particles including TMV, M13, and Au nanorods to construct 3D structures. During the self-assembly process of TMV-P4VP structures, morphological transformation and TMV deformation were observed. The results confirmed that TMVs can stabilize the P4VP particles in water by covering their exterior surface. Meanwhile, the method can be used to assemble M13 and Au nanorods. This unique self-assembly behavior will open up a new way to assemble and organize rod-like particles hierarchically.

In chapter three, we will discuss the co-assembly method to prepare the size-controlled and functionality-remained protein-polymer core-shell structures. The size of colloids can be easily controlled by adjusting the mass ratios of proteins and P4VP, confirmed by DLS and TEM. Besides, not only P4VP, but also biodegradable PCL-b-P2VP can be used to form colloids, which will be a good vehicle for the application of drug delivery. The conformational structures and functionalities of proteins are remained.

In chapter four, we will discuss applying template synthesis method to fabricate polymer-BNPs core-shell structures using positively charged polystyrene (PS) microspheres. Electrostatic interaction is the main driving force in this template synthesis method. BNPs including P22 and TMV can be coated to the surface of PS spheres. A close-packed structure with full coverage of BNPs can be realized.

In chapter five, we will discuss the atom transfer radical polymerization (ATRP) method to prepare the BNPs-polymer core-shell structures. The post-functionalization of apo-HSF can be realized by a CuAAC reaction, and an in situ ATRP reaction on the outer surface of apoferritin. These transformations afford versatile methods to alter the properties of apoferritin particles, and can be extended to other bionanoparticle such as rod-like TMV particles.

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