Cellular models have been the backbone of models for drug therapeutics, discovery, or diagnostics, and for modeling a tumor microenvironment to understand the proliferation, migration, invasion, dormancy, angiogenesis, Conventional two-dimensional (2D) cell culture models are used because of the cost-effectiveness compared to animal models. But these models fail to mimic the cellular phenotype of a three-dimensional (3D) microenvironment. As a result, it is important to develop a 3D model that predicts cellular behaviors and their interaction with neighboring cells and extracellular matrix (ECM) in a more realistic setting. Various 3D cell culture methods have been employed to generate spheroids, in vitro, but most of these platforms face drawbacks such as spheroid size heterogeneity, low yield, use of specialized instruments etc. The hydrogel platform mentioned here was able to solve all the previous problems and can create a novel 3D tumor microenvironment. This thesis is focused on developing an in-vitro 3D model which can modulate the tumor microenvironment consisting of cancer cells and macrophages and how the Amikagel platform modulated the macrophage phenotype is discussed in detail here. This platform can be an ideal platform for macrophage phenotype modulation.

Adoptive cell therapies such as chimeric antigen receptor (CAR) modified immune cells are revolutionizing cancer treatment. These innovative immunotherapies have a promising outlook for liquid cancers, but lack robustness against solid tumors due to complex variables introduced by the tumor microenvironment (TME). Additionally, existing CAR-T cell treatments are commonly accompanied by toxic side effects. However, by grafting a CAR construct onto macrophages, a professional phagocytic innate cell which are actively recruited by solid tumors, the efficacy of this treatment is hoped to be extended beyond hematological malignancies. Moreover, the introduction of energy metabolite-based polymers (EMPs) to provide a sustained release of activating F16BP-poly(I:C) microparticles could address the toxicity complications that arise from CAR treatments. It was determined that PLGA-F16BP-poly(I:C) microparticles allow for CAR-macrophage activation in vitro, though not in a sustained manner. Moreover, F16BP-poly(I:C) microparticles were better geared toward reducing cytokine related toxicity in vitro, with in vivo results remaining inconclusive. These findings suggest prioritization between macrophage activation or cytokine storm reduction would be required at this time, though additional future studies to explore variables such as CAR-macrophage sensitivity and the positive control could help refine this immunotherapy.