Layer-by-Layer Nanoparticles for Systemic Codelivery of an Anticancer Drug and siRNA for Potential Triple-Negative Breast Cancer Treatment

A single nanoparticle platform has been developed through the modular and controlled layer-by-layer process to codeliver siRNA that knocks down a drug-resistance pathway in tumor cells and a chemotherapy drug to challenge a highly aggressive form of triple-negative breast cancer. Layer-by-layer films were formed on nanoparticles by alternately depositing siRNA and poly-l-arginine; a single bilayer on the nanoparticle surface could effectively load up to 3500 siRNA molecules, and the resulting LbL nanoparticles exhibit an extended serum half-life of 28 h. In animal models, one dose via intravenous administration significantly reduced the target gene expression in the tumors by almost 80%. By generating the siRNA-loaded film atop a doxorubicin-loaded liposome, we identified an effective combination therapy with siRNA targeting multidrug resistance protein 1, which significantly enhanced doxorubicin efficacy by 4 fold in vitro and led to up to an 8-fold decrease in tumor volume compared to the control treatments with no observed toxicity. The results indicate that the use of layer-by-layer films to modify a simple liposomal doxorubicin delivery construct with a synergistic siRNA can lead to significant tumor reduction in the cancers that are otherwise nonresponsive to treatment with Doxil or other common chemotherapy drugs. This approach provides a potential strategy to treat aggressive and resistant cancers, and a modular platform for a broad range of controlled multidrug therapies customizable to the cancer type in a singular nanoparticle delivery system.Janssen Pharmaceutical Ltd. (TRANSCEND Grant)National Cancer Institute (U.S.) (Koch Institute Support (Core) Grant P30-CA14051)National Health and Medical Research Council (Australia) (CJ Martin Fellowship)National Science Foundation (U.S.). Graduate Research FellowshipNatural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship

Biomimetic Polymeric Particle Therapeutics for Enhanced Drug Delivery and Cancer Immunotherapy

Polymeric micro- and nanoparticles have been utilized in the treatment of various diseases, such as cancer and infectious disease, but there is a need for more effective delivery of these particles to their intended targets and enhanced interaction with their target cells. Biomaterial-based devices can have enhanced therapeutic function through biomimicry of naturally occurring structures. The goal of this thesis work was to engineer multiple particle parameters, including size, shape, protein presentation, surface fluidity, polymer structure, hydrophobicity, and targeting capability, to create novel biomimetic polymeric micro- and nanoparticle platforms for enhanced drug delivery and cancer immunotherapy. Immunoengineering is a particularly clinically relevant application for particle therapeutics due to the recent clinical success of cancer immunotherapy and the pervasive role of the immune system in human disease. Chapter one outlines the guiding aims of this thesis. Chapter two provides background on biomimetic particle design, focusing on cell membrane coating, artificial antigen presenting cells, and biomaterials for gene delivery. Chapters three and four describe the engineering of biomimetic anisotropic red blood cell and platelet membrane-coated particles, respectively, for enhanced stealth drug delivery. In chapter five, I describe the use of anisotropic nanoscale artificial antigen presenting cells for treatment of melanoma. And finally, in chapter six, I detail my work developing novel bioreducible lipophilic poly(beta-amino ester) nanoparticles for targeted mRNA delivery to dendritic cells and their ultimate use as a therapeutic cancer vaccine. Overall, I have developed biomimetic polymeric particles that mimic red blood cells, platelets, antigen presenting cells, and viruses, by precise engineering and modulation of various particle characteristics in order to optimize biomimicry and therapeutic function. The modular off-the-shelf particle platforms developed here have been found to have enhanced efficacy for their respective therapeutic applications and show significant promise in treating a range of disease states

Biomimetic Polymeric Particle Therapeutics for Enhanced Drug Delivery and Cancer Immunotherapy

Polymeric micro- and nanoparticles have been utilized in the treatment of various diseases, such as cancer and infectious disease, but there is a need for more effective delivery of these particles to their intended targets and enhanced interaction with their target cells. Biomaterial-based devices can have enhanced therapeutic function through biomimicry of naturally occurring structures. The goal of this thesis work was to engineer multiple particle parameters, including size, shape, protein presentation, surface fluidity, polymer structure, hydrophobicity, and targeting capability, to create novel biomimetic polymeric micro- and nanoparticle platforms for enhanced drug delivery and cancer immunotherapy. Immunoengineering is a particularly clinically relevant application for particle therapeutics due to the recent clinical success of cancer immunotherapy and the pervasive role of the immune system in human disease. Chapter one outlines the guiding aims of this thesis. Chapter two provides background on biomimetic particle design, focusing on cell membrane coating, artificial antigen presenting cells, and biomaterials for gene delivery. Chapters three and four describe the engineering of biomimetic anisotropic red blood cell and platelet membrane-coated particles, respectively, for enhanced stealth drug delivery. In chapter five, I describe the use of anisotropic nanoscale artificial antigen presenting cells for treatment of melanoma. And finally, in chapter six, I detail my work developing novel bioreducible lipophilic poly(beta-amino ester) nanoparticles for targeted mRNA delivery to dendritic cells and their ultimate use as a therapeutic cancer vaccine. Overall, I have developed biomimetic polymeric particles that mimic red blood cells, platelets, antigen presenting cells, and viruses, by precise engineering and modulation of various particle characteristics in order to optimize biomimicry and therapeutic function. The modular off-the-shelf particle platforms developed here have been found to have enhanced efficacy for their respective therapeutic applications and show significant promise in treating a range of disease states

Biodegradable lipophilic polymeric mRNA nanoparticles for ligand-free targeting of splenic dendritic cells for cancer vaccination

Nanoparticle (NP) -based mRNA cancer vaccines hold great promise to realize person-alized cancer treatments. To advance this technology requires delivery formulations for efficient intracellular delivery to antigen-presenting cells. We developed a class of bioreducible lipophilic poly(beta- amino ester) nanocarriers with quadpolymer architec-ture. The platform is agnostic to the mRNA sequence, with one -step self-assembly allow-ing for delivery of multiple antigen-encoding mRNAs as well as codelivery of nucleic acid-based adjuvants. We examined structure-function relationships for NP-mediated mRNA delivery to dendritic cells (DCs) and identified that a lipid subunit of the pol-ymer structure was critical. Following intravenous administration, the engineered NP design facilitated targeted delivery to the spleen and preferential transfection of DCs without the need for surface functionalization with targeting ligands. Treatment with engineered NPs codelivering antigen-encoding mRNA and toll -like receptor agonist adjuvants led to robust antigen-specific CD8+ T cell responses, resulting in efficient antitumor therapy in in vivo models of murine melanoma and colon adenocarcinoma

Layer-by-Layer Nanoparticles for Systemic Codelivery of an Anticancer Drug and siRNA for Potential Triple-Negative Breast Cancer Treatment

A single nanoparticle platform has been developed through the modular and controlled layer-by-layer process to codeliver siRNA that knocks down a drug-resistance pathway in tumor cells and a chemotherapy drug to challenge a highly aggressive form of triple-negative breast cancer. Layer-by-layer films were formed on nanoparticles by alternately depositing siRNA and poly-l-arginine; a single bilayer on the nanoparticle surface could effectively load up to 3500 siRNA molecules, and the resulting LbL nanoparticles exhibit an extended serum half-life of 28 h. In animal models, one dose <i>via</i> intravenous administration significantly reduced the target gene expression in the tumors by almost 80%. By generating the siRNA-loaded film atop a doxorubicin-loaded liposome, we identified an effective combination therapy with siRNA targeting multidrug resistance protein 1, which significantly enhanced doxorubicin efficacy by 4 fold <i>in vitro</i> and led to up to an 8-fold decrease in tumor volume compared to the control treatments with no observed toxicity. The results indicate that the use of layer-by-layer films to modify a simple liposomal doxorubicin delivery construct with a synergistic siRNA can lead to significant tumor reduction in the cancers that are otherwise nonresponsive to treatment with Doxil or other common chemotherapy drugs. This approach provides a potential strategy to treat aggressive and resistant cancers, and a modular platform for a broad range of controlled multidrug therapies customizable to the cancer type in a singular nanoparticle delivery system