Synthetic organic materials for targeting immunotherapies to lymph nodes

Immunotherapies have yielded tremendous advances over the last three decades. However even the most promising therapies, for example monoclonal antibodies, require systemic infusion that can limit dosing and lead to off target immunotoxicity. To address such challenges and improve immunotherapy, the field is investing in synthetic biomaterials to target lymph nodes (LNs) - sites of coordinated immune activation and suppression. These synthetic materials allow enhanced targeting, retention, and control over the signals that are required to elicit desired immune processes during immunotherapy. Two broad classes of materials that have been employed for LN targeting include synthetic lipids and polymers. This review will discuss how the chemistries of these materials can be leveraged to improve lymph node targeting of immunotherapies to treat disease. We will also provide commentary on translational barriers to the clinic, an outlook on current therapies that are clinically used, and a forward-looking perspective.