Nano-Based Vaccine Delivery Systems: Innovative Therapeutics Against Cancer and Neurological Disorders.

Vaccines have emerged as one of the most effective biomedical strategies for the eradication of diseases. However, a significant limitation remains in their ability to induce comprehensive humoral and cellular immune responses. Recently, nanoparticles (NPs) have been advanced as a novel vaccine delivery approach to address reduced immunogenicity. Several nanoparticle-based agents have now been approved for human use, and NP-based formulations have shown remarkable potential to enhance immunogenicity and stability, supporting targeted delivery and controlled release either through co-encapsulation of adjuvants such as Toll-like receptor (TLR) agonists or the inherent immune-stimulatory properties of NP materials in minimizing cytotoxicity. Despite these advances, there remains a pressing need for vaccines capable of addressing complex and multifactorial diseases such as neurological disorders and cancer. Nanotechnology could be a viable solution to this challenge. The use of lipid-based NPs, particularly those encapsulating mRNA, has garnered attention for its adaptability in vaccine delivery. Current studies indicate that NP composition, surface charge and size may play a crucial role in modulating biodistribution, delivering immune-stimulatory molecules, targeting antigens and trafficking antigen-presenting cells (APCs), which enhance immune responses across mucosal and systemic tissues. This review highlights recent advancements in NP-based vaccines and delivery systems, and adjuvants for cancer and neurological disorders. The review also covers an overview of NP-based and alternative delivery systems, focusing on the mechanisms and innovations related to NP-based systems for immunotherapeutic applications in cancer and neurological disorders.