Page - (000384) - in Biomedical Chemistry: Current Trends and Developments

surface with the aim to induce rapid and short immune responses. However, this method also suffers from low stability and rapid degradation (Kalkanidis, 2006; Sloat, 2010). It is currently known that the immunostimulatory products with large hydrophobic structures are more immunostimulative than hydrophilic compounds. Therefore, it is proposed that microbially derived adjuvants can be replaced with hydrophobic nanomaterials. These nanosystems can also simultaneously serve as delivery vehicles for the immunostimulative molecules (Kipper, 2002), with the aim of facilitating single-dose vaccination and eliminate the need for booster shots through sustaining the release of immunotherapeutic payloads and potentiating their effect via the intrinsic adjuvanticity of the nanoparticles. In addition, most of the nanoparticles applied for cancer immunotherapy possess high safety, and controllable rate of degradation for the antigen release (Kersten, 2004). Owing to these benefits, it can be possible to avoid the need for surgical removal of cancer tissues and circumvent the disadvantages of conventional anticancer formulations by combining chemo- and immunotherapeutic approaches using such nanostructures. Below we discuss the adjuvanticity of nanoparticles as well as the current progresses in the development of nanovaccines, particularly those with high potential to be used for cancer therapy. 3.5.4.2 Nanoparticulate Adjuvants for Cancer Immunotherapy Adjuvants are immunogenic compounds capable of accelerating and extending the immunostimulative response of biomolecules. Currently, alum salts are the most widely used immune adjuvants (Correia-Pinto, 2013), owing to their potential in triggering the so-called “inflammasome” mechanism in the cells, that leads to the release of danger signals and subsequent secretion of pro-inflammatory biomolecules, resulting in the activation of the immune system (Marrack, 2009). Despite the popularity of immunogenic alum salts and other conventional adjuvants over the last few decades, they suffer from major limitations, such as adverse local reactions, degradation during freeze-drying, lack of inducing cellular immune responses and necessity