By Aliasger K. Salem
Vaccines can be used to efficiently manage and eradicate many dangerous diseases. In previous AAPS Blog posts, I have discussed the significant potential of biodegradable nanoparticles in vaccine delivery and the potential for using them to treat a wide range of diseases from cancers to dust mite allergies. However, other afflictions such as tumors and diseases caused by intracellular pathogens still need effective preventative or therapeutic vaccines. In developing nations, there is a need for vaccine dosage forms with stable shelf lives and vaccine formulations that reduce or remove the number of boosts that are needed. For example, inactivated influenza vaccines need to be stored within a narrow temperature range of 2 to 8°C. This necessitates a well-controlled cold chain that causes distribution and storage to be complex and expensive.
As our understanding of the immune system continues to develop, considerable research has been focused on improving vaccine delivery approaches. Biodegradable nanoparticles can act as depots that provide sustained release of antigens, enhance uptake of the antigens by antigen-presenting cells, and stimulate and activate antigen-presenting cells in addition to promoting cross-presentation of antigens. Biodegradable nanoparticles have the potential to protect antigens and adjuvant from enzymatic degradation and denaturation. Biodegradable nanoparticles can be loaded with multiple synergistic agents allowing for simultaneous delivery of multiple antigens and immunostimulatory adjuvants. Nanoparticles can also be readily surface-engineered with cell binding/targeting ligands and/or other moieties. The ease of design and use combined with multifunctionality makes using biodegradable nanoparticles a versatile and useful delivery strategy for vaccines and immunotherapies.
I am pleased to announce the completion of a new AAPS Journal theme, Nanoparticles in Vaccine Delivery, where we present recent progress in the development of a variety of different classes of biodegradable nanoparticles used for vaccine delivery. These include positively charged liposomes, pH responsive nanoparticles, peptide amphiphile based micelles, and nanoparticles formed from polysaccharides and biodegradable polymers such as polyanhydrides and polylactic-co-glycolide. This AAPS Journal theme demonstrates the wide repertoire of materials that can be used to fabricate nanoparticles and the many types of nanoparticles from micelles to liposomes that can be used to deliver vaccines. Preclinical studies presented in this theme show that nanoparticles can be safe and can be used for vaccine delivery to enhance therapeutic responses against a wide range of diseases from dust mite allergies to cancers. Nanoparticles have immense potential for continued development in vaccine delivery, and it is becoming increasingly evident that each disease will need nanoparticles with specific design criteria that are tailored to augmenting the therapeutic response to that specific disease.