Fig. 18

A The use of nanoparticles to target the microenvironments of tumors and premetastatic areas. Part A shows how the tumor vasculature or stromal cells in the tumor microenvironment can be targeted. Part B shows targeting of premetastatic microenvironments such as the bone marrow niche, where nanoparticles can be used to enhance bone strength and volume through osteogenic differentiation of mesenchymal stem cells. To achieve cell-specific targeting, nanoparticles can be modified with ligands that bind to specific receptors on the surface of target cells. However, even without targeting ligands, nanoparticles can still be engineered for preferential uptake by these cells. The cells can also take up the payloads released from the nanoparticles that are localized in tumors or premetastatic tissues, even in a non-specific manner. Reprint from [177] with a permission from Springer Nature. B Manipulating tumor hypoxia using biomaterials. A range of biomaterial-based techniques, such as oxygen production and transportation systems, can be utilized to control hypoxia within tumors and their surrounding microenvironments. Reprint from [244] with a permission from Springer Nature. C Utilizing Biomaterials to Decrease Tumor Acidity and Control ROS Levels. A variety of biomaterials-focused approaches, especially those involving calcium-carbonate-based materials, can be introduced into the tumor surroundings to counteract tumor acidity. Reactive oxygen species (ROS) levels can be regulated using oxygen-free radical-absorbing hydrogels. These hydrogels can also serve as vehicles for delivering antibodies and chemotherapy medications. DNCaNP refers to liposome-encapsulated calcium nanoparticles, ICB stands for immune checkpoint blockade, PDA denotes polydopamine, and Treg cell represents regulatory T cells. Reprint from [244] with a permission from Springer Nature