Improving Vaccine and Immunotherapy Design Using Biomaterials

Abstract

Polymers, lipids, scaffolds, microneedles, and other biomaterials are rapidly emerging as technologies to improve the efficacy of vaccines against infectious disease and immunotherapies for cancer, autoimmunity, and transplantation. New studies are also providing insight into the interactions between these materials and the immune system. This insight can be exploited for more efficient design of vaccines and immunotherapies. Here, we describe recent advances made possible through the unique features of biomaterials, as well as the important questions for further study.

Keywords: autoimmunity and transplantation; biomaterial and nanotechnology; cancer; infectious disease; nanoparticle and microparticle; vaccine and immunotherapy.

Figure 1. Key Classes of Biomaterials Being Used to Study and Control Immune Function

These efforts involve (A) liposomes, (B) polymer nanoparticles and microparticles, (C) self-assembled materials, (D) polymer scaffolds, and (E) microneedles and other macroscopic devices.

Figure 2. Strategies Involving Biomaterials for Engineering Immune Function

(A) Material shape, size, chemistry, and other physicochemical properties impact drainage through lymphatics, interactions with APCs, and the intrinsic immunogenicity of many common polymers. (B) Biomaterials can be used to control the combinations and relative concentrations of immune cargos reaching APCs and lymphocytes, or, by designing polymers with a desired degradation rate, the cargo delivery kinetics. (C) Scaffolds can be used to control the context or density in which antigens and adjuvants are displayed, and as local environments to recruit APCs or lymphocytes (e.g., by incorporation of chemokines). (D) T cells, APCs, and other immune cells can be modified with nanoparticles incorporating immune signals to exert autocrine effects on the modified cells, or to exert paracrine effects on target cells and tissue to which the modified cell will migrate (e.g., a tumor). (E) Microneedles coated with or incorporating immune cues increase safety and patient compliance by efficiently targeting skin-resident immune cells without pain, generation of medical sharps, or need for refrigeration. (F) Biomaterial carriers can be engineered with specific moieties to control cellular entry and intracellular trafficking for directing spatially restricted immune processes (e.g., TLR signaling and antigen processing). (G) Stimuli responsive materials can exploit physiological (e.g., changes in pH or temperature) or external cues (e.g., UV light) to provide environment-specific control within cells, target tissues, or tumors (e.g., access to neoantigens during NP-enabled local ablation via photothermal exposure). (H) NPs and MPs can alter how antigens are processed to modulate responses away from proimmune and toward regulation. Abbreviations: APC, antigen-presenting cell; MP, microparticle; NP, nanoparticle; TLR, Toll-like receptor.