Nanoparticles play a critical role in cancer immunotherapy and tumor microenvironment (TME) remodeling. They can enhance immunotherapy by targeting immune cells, modulating the TME, and improving immune responses. Nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells. Exosomes, whether naturally secreted or bioengineered, can regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, have potential in accelerating immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. Nanoarchitectures are promising structures in vaccine development due to their ability to induce long-term immunity. The TME is a complex environment composed of macrophages, fibroblasts, and immune cells that play a crucial role in immune response modulation. Macrophages, particularly tumor-associated macrophages (TAMs), are a significant component of the TME and can be polarized into M1 or M2 phenotypes. M1 macrophages have pro-inflammatory and anti-cancer functions, while M2 macrophages promote tumor growth and immunosuppression. Nanoparticles can be used to re-educate TAMs, change their phagocytic ability, suppress TAMs, and deliver drugs to TAMs for cancer immunotherapy. Cancer-associated fibroblasts (CAFs) are another important component of the TME. They play a pivotal role in tumorigenesis by inducing biochemical alterations and signaling network changes that accelerate tumor development. CAFs can be categorized into carcinogenic and anti-carcinogenic subtypes, with different roles in cancer progression. Nanoparticles can be used to engineer CAFs to act as antigen-presenting cells (APCs) and stimulate antigen-specific CD8+ T cells in cancer immunotherapy. Neutrophils, natural killer (NK) cells, and T cells are also important components of the TME. Neutrophils can be divided into N1 and N2 subtypes, with N1 neutrophils mediating toxic impacts on cancer cells. NK cells are innate lymphocytes that can be engineered to enhance cancer immunotherapy. T cells, particularly CD8+ T cells, play a crucial role in cancer immunotherapy. However, T cell exhaustion can impair immune responses, and nanoparticles can be used to enhance T cell function. Endothelial cells and pericytes are also important components of the TME. Endothelial cells form the inner lining of blood vessels and play a crucial role in maintaining vascular homeostasis. Pericytes regulate blood vessel development and modulate blood flow, coagulation, and vascularNanoparticles play a critical role in cancer immunotherapy and tumor microenvironment (TME) remodeling. They can enhance immunotherapy by targeting immune cells, modulating the TME, and improving immune responses. Nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells. Exosomes, whether naturally secreted or bioengineered, can regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, have potential in accelerating immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. Nanoarchitectures are promising structures in vaccine development due to their ability to induce long-term immunity. The TME is a complex environment composed of macrophages, fibroblasts, and immune cells that play a crucial role in immune response modulation. Macrophages, particularly tumor-associated macrophages (TAMs), are a significant component of the TME and can be polarized into M1 or M2 phenotypes. M1 macrophages have pro-inflammatory and anti-cancer functions, while M2 macrophages promote tumor growth and immunosuppression. Nanoparticles can be used to re-educate TAMs, change their phagocytic ability, suppress TAMs, and deliver drugs to TAMs for cancer immunotherapy. Cancer-associated fibroblasts (CAFs) are another important component of the TME. They play a pivotal role in tumorigenesis by inducing biochemical alterations and signaling network changes that accelerate tumor development. CAFs can be categorized into carcinogenic and anti-carcinogenic subtypes, with different roles in cancer progression. Nanoparticles can be used to engineer CAFs to act as antigen-presenting cells (APCs) and stimulate antigen-specific CD8+ T cells in cancer immunotherapy. Neutrophils, natural killer (NK) cells, and T cells are also important components of the TME. Neutrophils can be divided into N1 and N2 subtypes, with N1 neutrophils mediating toxic impacts on cancer cells. NK cells are innate lymphocytes that can be engineered to enhance cancer immunotherapy. T cells, particularly CD8+ T cells, play a crucial role in cancer immunotherapy. However, T cell exhaustion can impair immune responses, and nanoparticles can be used to enhance T cell function. Endothelial cells and pericytes are also important components of the TME. Endothelial cells form the inner lining of blood vessels and play a crucial role in maintaining vascular homeostasis. Pericytes regulate blood vessel development and modulate blood flow, coagulation, and vascular