Immunomodulatory activities of carbon quantum dots on the primary macrophages and whole splenocytes

Quantum dots, because of some of their fascinating features, like continuous radiation emission, crossing the biological barrier, and potential for drug carrying, have emerged as versatile nanomaterials in enormous applications relating to drug development and health sciences. Among such quantum dots, carbon quantum dots have gained widespread attention due to their low toxicity, high biocompatibility, and excellent photostability. The present work investigates the immunomodulatory properties of CQDs with diverse chemical characteristics against primary macrophages and whole splenocytes. Since macrophages are important regulators of immune responses, their isolation and activation by toll-like receptor agonists were performed to evaluate the production of pro-inflammatory cytokines and intracellular signaling pathways. Our data indicate that different CQD formulations possess specific immunomodulatory activities, while some of them reveal adjuvant capabilities; others act anti-inflammatory. Importantly, the zinc-containing CQDs enhance pro-inflammatory responses, which may find applications as vaccine adjuvants. These findings highlight the therapeutic possibilities of CQDs in the treatment of inflammatory diseases and enhancement of vaccine efficacy.