Page - (000383) - in Biomedical Chemistry: Current Trends and Developments

immunotherapeutic formulation are high safety, the capability of eliciting the desired immune responses after a single dose, absence of a booster dose, absence of the premature drug release, simple and affordable preparation process, easy administration and scaling-up process, and high physicochemical stability of the immunogenic agents and excipients throughout the process, storage and administration (Oyewumi, 2010). To combine all these properties in one formulation, nanoparticles have been suggested as versatile systems capable of improving the biological effects of the immunostimulatory molecules via different mechanisms. One of the benefits of nanovaccines is that the morphology, size distribution, entrapment efficiency, release kinetics and other physicochemical properties, which affect the obtained immune responses can be controlled, leading to the successful development of promising vaccines (Kendall, 2006). In addition, the systemic severe side effects of high dose administration of the immunostimulants, such as toll-like receptor ligands (Heikenwalder, 2004), can be minimized using nanoparticles. Nanoparticles can also reduce the needed dose and limit the non-specific immune responses (Diwan, 2004). Nanomaterial-based immunotherapy is a relatively new interdisciplinary field holding great promise by combining materials science, chemistry and immunology. The immunostimulative biomolecules can be either captured within or conjugated on the surface of the nanoparticles (Nembrini, 2011; Xiang, 2013). The former method offers distinct advantages, such as reduced dose of antigen, efficient uptake and processing by antigen presenting cells (APCs), increased stability during storage and long-term immune response to the therapy (Foster, 2010; Katare, 2003). Although the entrapment of immunogenic biomolecules within the particles is offered as the best possible protective strategy, the main drawback of this method is the unavailability of the loaded antigens upon administration because of the slow drug release profiles (Kazzaz, 2000). In addition, the loaded bio-immunogenics can physically or chemically degrade during the loading process (Jung, 2001). This method also causes a lower extent of immunity compared to the nanoparticles that have immunostimulative molecules chemically conjugated or physically adsorbed on their