Development of non-viral nano-carriers for gene delivery and COVID-19 vaccines

Author

Zhongyu Li, New Jersey Institute of TechnologyFollow

Author ORCID Identifier

0000-0002-9566-5771

Document Type

Dissertation

Date of Award

5-31-2023

Degree Name

Doctor of Philosophy in Chemical Engineering - (Ph.D.)

Department

Chemical and Materials Engineering

First Advisor

Xiaoyang Xu

Second Advisor

Rajesh N. Dave

Third Advisor

Xianqin Wang

Fourth Advisor

Murat Guvendiren

Fifth Advisor

Bu Lei

Abstract

Gene therapy is one of the most promising medical fields with the potential to effectively advance the treatment of difficult diseases by producing therapeutic proteins or repairing defective gene sequences. However, gene therapy presents severe challenges in delivery including renal clearance, phagocytosis, enzymatic degradation, protein absorption, and cellular internalization barriers, which have been barriers for translation into the clinic. Naked nucleic acids, with their intrinsic negative charge, electrostatically repulse the anionic cell membrane, preventing cellular uptake. Also, they are considered foreign genetic material when introduced into the body and are rapidly cleared by the reticuloendothelial system or degraded by nucleases, rarely reaching the site of action. Therefore, nucleic acids require a delivery vehicle that not only protects the gene payload from degradation but also allows them to enter cells.

Among all the categories of gene delivery methods, the nanoparticle-based vectors are the most clinically advanced gene delivery platforms, exemplified most clearly by the two COVID-19 vaccines which incorporate lipid nanoparticles. Hence, this doctoral dissertation aims to discuss the development of non-viral nanoparticle-mediated gene delivery vectors and investigate the transfection efficacy in vitro and in vivo. Specifically, the polymeric and lipid nanoparticle-based gene delivery vectors and their applications as DNA and mRNA COVID-19 vaccines are explored.

In Chapter 1, the background and challenges of gene delivery and gene therapies are introduced, including the advantages and disadvantages of different gene delivery vectors. Furthermore, the objectives of this doctoral dissertation are laid out.

In Chapter 2, a polymeric nanoparticle-based "Nanoparticle Depot" system is developed for controlled and sustained gene delivery. This system prolongs the gene release over 8 days and enhances the expression of encapsulated DNA plasmid over time.

In Chapter 3, a lipid-polymer hybrid "Particle-in-Particle" (PNP) nanostructure gene delivery platform is developed. The top-performing PNP/C12-PBAE nanoparticle-based delivery vector shows enhanced DNA and mRNA transfection efficacy, sustained gene release behavior, and capability of long-term lyophilization for storage. Furthermore, the lyophilized DNA and mRNA PNP-based COVID-19 vaccines are investigated in vitro and in vivo.

In Chapter 4, a library of 144 lipid-like materials is synthesized through one-step enzyme-catalyzed esterification and formulated into lipid nanoparticles (LNPs) for mRNA delivery. The top-performing AA3-DLin LNPs show much-enhanced mRNA transfection efficacy compared to FDA-approved ALC-0315 and MC3 LNPs. Moreover, AA3-DLin LNP-based mRNA COVID-19 vaccines are developed and the immunogenicity in a BALB/c mouse model is investigated.

These newly developed nanoparticles exhibit great potential in gene delivery and therapeutics. More importantly, this dissertation provides a comprehensive bottom-up methodology of non-viral based polymeric and lipid nanoparticle-mediated gene delivery vectors development from design, synthesis, screening, optimization, fabrication, characterization as well as in vitro and in vivo applications.

Recommended Citation

Li, Zhongyu, "Development of non-viral nano-carriers for gene delivery and COVID-19 vaccines" (2023). Dissertations. 1768.
https://digitalcommons.njit.edu/dissertations/1768