Targeted Delivery Systems based on Protein-Nanoparticle Hybrid Platform for Cancer Therapy

Abstract

Cancer, defined as an abnormal growth of cells in tissues and invading other parts of the body leading to mortality, has constantly plagued humanity in history regardless of age or sex. Overcoming this hardship is one of the most urgent challenges for us and the next generation. For cancer treatment, the abilities both targeting cancer cells and delivering therapeutic drugs are critical. This situation has led to a lot of interest in the development of nanoparticles that can carry large amounts of drugs and attach target ligands through surface chemistry. However, the developed nanoparticle based target delivery systems induced an immune response in biological environment and caused instability in the surface modification process. In this context, the development of stable, effective and intuitive “Target Delivery Systems (TDS)” based on nanoparticle is of great significance. In this dissertation, a novel TDSs based on Protein-Nanoparticle conjugation have been designed. Recruiting a functional fusion-protein, we developed a targeting systems with a protein corona shied (PCS) concept in which nanoparticles are supramolecularly pre-coated for reducing biological protein adsorption while retaining targeting ability. In addition, we figure out the intuitive interaction between Metal Organic Framework (MOF) and the most conventional and powerful targeting ligand, antibody, can make the robust and facile TDSs without any chemical modification steps. In chapter 2, we developed a targeting strategy for nanoparticles incoporated with a pre-coated recombinant fusion protein in which HER2-binding affibody combines with glutathione-S-transferase (GST-HER2). Once thermodynamically stabilized in preferred orientations on the surface of nanoparticles trough a linker which can target specific site of proteins, the adsorbed fusion proteins as a corona minimize interactions with biological proteins to prevent the clearance of nanoparticles by macrophages, while ensuring systematic targeting functions in vitro and in vivo. This study provides insight into the use of the supramolecularly built protein corona shield as a targeting agent through regulating the interfaces between nanoparticles and biological systems. In chapter 3, we developed a plug-and-playable delivery system based on the bio-conjugation between the fusion protein coated silica nanoparticle and antibody. We prepared an adaptor fusion protein, GST-ABD, which was constructed by genetically fusing glutathione-S-transferase (GST) and antibody-binding domain (ABD) of Protein A and used it to mediate efficient complexation between targeting antibodies and silica nanoparticle without any complicated modifications. GST-ABDs were successfully anchored with specific alignment on the surface of nanoparticle through the GST active site target linker (GSH) and the GST-ABD-NP efficiently captured various targeting antibodies in an orientation-controlled manner through the selective interaction between displayed ABDs and the Fc region of the antibodies. Their target-specific delivery ability by surface-displayed targeting antibodies was confirmed by fluorescence cell imaging and cell viability tests. In chapter 4, we developed a Hybrid complex for Zr-MOF nanoparticles incorporated with the stably pre-coated GST-Affibody (GST-HER2, GST-EGFR) protein by supramoleculary assemble e without any chemical modification. We modulated the solvent site on the MOF nanoparticles by coating with the clocking proteins, GST-Affibody. At the same time, as described in the previous chapter, the cloaking proteins such as GST-Affibody stabilized in preferred orientations on the surface of nanoparticle, it can minimize the biological protein adsorption n with retaining target moiety. We effectively controlled the MOF surface via an intuitive reaction between the solvent site and designed proteins to develop a versatile targeted drug delivery platform. This study provides an insight into the potential applications of Zr-MOFs in nanomedicine and the future of the biointerface of MOFs. In chapter 5, we developed a robust and simple target platform strategy with “plug & play” concept for MOF incorporated with the stably pre-coated antibody in which any kind. Once thermodynamically stabilized in proper alignment with the active sites of MOF, the absorbed antibody ensures systematic targeting functions to any cell we want while minimizing interactions with serum proteins to prevent the clearance of nanoparticles by macrophages. This study provides insight into the use of the stable built plug & play concept as a powerful targeting platform through simple combining between MOF and antibody for further variety of applications.