Enhancing Immunity with Nanomedicine: Employing Nanoparticles to Harness the Immune System.

The failure of immune responses to vaccines and dysfunctional immune responses to viral infection, tumor development, or neoantigens lead to chronic viral infection, tumor progression, or incomplete immune protection after vaccination. Thus, strategies to boost host immunity are a topic of intense research and development. Engineered nanoparticles (NPs) possess immunological properties and can be modified to promote improved local immune responses. Nanoparticle-based approaches have been employed to enhance vaccine efficacy and host immune responses to viral and tumor antigens, with impressive results. In this Perspective, we present an overview of studies, such as the one reported by Alam et al. in this issue of ACS Nano, in which virus-like particles have been employed to enhance immunity. We review the cellular cornerstones of effective immunity and discuss how NPs can harness these interactions to overcome the current obstacles in vaccinology and oncology. We also discuss the barriers to effective NP-mediated immune priming including (1) NP delivery to the site of interest, (2) the quality of response elicited, and (3) the potential of the response to overcome immune escape. Through this Perspective, we aim to highlight the value of nanomedicine not only in delivering therapies but also in coordinating the enhancement of host immune responses. We provide a forward-looking outlook for future NP-based approaches and how they could be tailored to promote this outcome.