Engineering nanomaterial physical characteristics for cancer immunotherapy

The physical properties of nanomaterials — such as size, structure, shape, charge, mechanical strength and hydrophobicity — can directly or indirectly influence immune cell functions and modulate immune responses in healthy and disease states. Therefore, nanomaterials can be designed with distinct physicochemical features for applications in immunobioengineering to achieve specific immunological effects. In this Review, we discuss how the physical features of natural and synthetic nanomaterials can affect protein adsorption, immune scavenging, biodistribution, immune cell targeting and toxicity. We highlight the nanoengineering advances that have enabled tailoring of the physical characteristics of nanomaterials for applications in cancer immunoengineering, and we outline the challenges in nanomaterials-based immunoengineering that need to be addressed to enable clinical translation. Physical properties affect immune signalling and effector functions in distinct immune cell subtypes. This Review discusses the impact of engineering nanomaterial physical characteristics on modulating immune responses and thus promoting efficient and effective cancer immunotherapy.