ABSTRACT

Nanoparticles were first developed in the mid-seventies by Birrenbach and Speiser (1976). Later, their application for the design of drug delivery systems was made available by the use of biodegradable polymers that were considered to be highly suitable for human applications (Couvreur et al., 1979). Many drugs were associated to nanoparticles, e.g. antibiotics, cytostatics. These systems were able to achieve tissue targeting and enhance intracellular penetration of drugs. As a result of the site specific targeting, avoidance of some organs was made possible, thereby reducing the side effects and toxicity of some active compounds. By contrast, the use of nanoparticles for vaccine delivery and, in general, for peptide and proteins has been poorly investigated. One reason might be due to the problems arising from the physico-chemical properties of these molecules, such as molecular weight, solubility, partition coefficient, degradability. However, several techniques, described in this review, were used to entrap peptides and proteins. Our main discussion will focus on the general aspects of protein and peptide entrapment into and release from nanoparticles. Attempts will be made to highlight the issues of formulating vaccine delivery systems using submicron polymeric carriers.