DOI
https://doi.org/10.25772/MECF-C330
Author ORCID Identifier
0009-0001-4979-0547
Defense Date
2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Pharmaceutical Sciences
First Advisor
Sandro da Rocha
Second Advisor
Joshua Reineke
Third Advisor
Phillip Gerk
Fourth Advisor
Matthew Halquist
Fifth Advisor
Rebecca Heise
Abstract
Osteosarcoma (OS) is the most common primary bone malignancy across all age groups, with a high propensity for metastasizing to the lungs. Pulmonary metastases, referred to as osteosarcoma lung metastases (OSLM), represent the leading cause of mortality in OS patients. Despite aggressive multi-agent chemotherapy regimens, such as the standard MAP protocol (methotrexate, doxorubicin, and cisplatin), outcomes for patients with OSLM remain poor, with five-year survival rates as low as 20–30%. Existing therapies are further limited by systemic toxicity, poor lung drug distribution, and a lack of effective immunotherapeutic responses, highlighting the urgent need for improved and localized treatment options.
This dissertation investigates a novel therapeutic strategy that combines local pulmonary administration (PA) with nanotechnology-based macrophage-targeting immunotherapies to shift the tumor microenvironment (TME) toward an antitumorigenic phenotype. Tumor-associated macrophages (TAMs) are highly abundant in OSLM and play a crucial role in maintaining an immunosuppressive, tumor-promoting environment. In this work, we explored two immunotherapeutic approaches to modulate TAM activity: (1) PLX-3397, and it liposomal formulation (L-PLX), a colony-stimulating factor 1 receptor inhibitor (CSF-1Ri), and (2) lipid nanoparticle (LNP) formulations encapsulating reporter mRNA (Fluc or eGFP).
In Aim# 01, we evaluated the pharmacokinetic (PK) profile of PLX following pulmonary administration in vivo, along with its efficacy in reprogramming TAMs in vitro and comparing it to L-PLX. In Aim #02, we designed and optimized mRNA LNP formulations for targeted transfection of macrophages and other cells within the OSLM TME, assessing their performance in vitro and in vivo, including a 3D spheroid model.
Collectively, this work demonstrates that local lung delivery of TAM-targeted nano-immunotherapies can enhance lung tissue exposure, reduce systemic toxicity, and promote a favorable immune response in the TME. These findings offer strong preclinical support for the clinical development of inhaled nanomedicine-based immunotherapies as adjuvant treatments for metastatic osteosarcoma.
Rights
© COPYRIGHT BY RANEEM RASMI ALDAQQA June 2025 All Rights Reserved © The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
7-27-2025