Particulate delivery systems for vaccines: what can we expect?

Abstract

In our attempts to thwart the unwanted attentions of microbes by prophylactic and therapeutic vaccination, the knowledge of interactions at the molecular level may prove to be an invaluable asset. This article examines how particulate delivery systems such as liposomes and polymer microspheres can be applied in the light of recent advances in immunological understanding. Some of the biological interactions of these delivery systems are discussed with relevance for antigen trafficking and molecular pathways of immunogenicity and emphasis on the possible interaction of liposomal components. In particular, traditional concepts such as antigen protection, delivery to antigen presenting cells and depot formation remain important aspects, whilst the inclusion of selected co-adjuvants and enhanced delivery of these moieties in conjunction with antigen now has a firm rationale.

Bile salts-containing vesicles: promising pharmaceutical carriers for oral delivery of poorly water-soluble drugs and peptide/protein-based therapeutics or vaccines

“…Conventional vesicular carriers can protect peptides and proteins to a certain extent from degradation in the GIT (Bramwell & Perrie, 2006). Yet, the existence of intestinal bile salts limit the capabilities of these carriers by cause membrane deformation and vesicles lysis resulting in the release of entrapped macromolecules from the vesicle preceding reaching its planned site of action (Wilkhu et al, 2013).…”

“…Vesicular carriers comprise of unilamellar or multilamellar spherical structures formed of lipid molecules gathered into bilayers orientation and capable of encapsulating drug molecules (Sinico & Fadda, 2009). Conventional vesicular systems exemplified by liposomes and niosomes have demonstrated an appealing potential in augmenting the oral bioavailability of therapeutic agents and immunogenic response of vaccines (Torchilin, 2005;Bramwell & Perrie, 2006). Nevertheless, the efficacy of conventional vesicles has been compromised by their instability in the GIT, which necessitated modification in their bilayers constructs to improve their in vivo resistance (Andrieux et al, 2009).…”

Genetic toxicology and preliminaryin vivostudies of nitric oxide donor tocopherol analogs as potential new class of antiatherogenic agents

“…Furthermore, in order to achieve the desired therapeutic response with these biodegradable polymeric devices, it is also important, to select the right polymer to be used as an encapsulating agent, since its nature significantly influences the size and the release profile of the nanoparticles [67]. These biodegradable polymers can be either natural (chitosan, alginate, carrageenan, albumin, gelatin, collagen, among others) or synthetic [poly(lactic acids), PLA), poly(lactide-co-glycolic acids), PLGA), poly(methyl methacrylate), PMMA), poly(ε-caprolactone), PCL), poly(alkylcyanoacrylates), PACA), and copolymers].…”

“…These biodegradable polymers can be either natural (chitosan, alginate, carrageenan, albumin, gelatin, collagen, among others) or synthetic [poly(lactic acids), PLA), poly(lactide-co-glycolic acids), PLGA), poly(methyl methacrylate), PMMA), poly(ε-caprolactone), PCL), poly(alkylcyanoacrylates), PACA), and copolymers]. The former generally provide a relatively quick drug release, while the latter enable extended drug release over periods from days to several weeks [67,68]. However, the use of synthetic polymer can be limited due to the need of organic solvents and harsh formulation conditions [58,68].…”

Characterization and optimization of bilosomes for oral vaccine delivery

“…For example, lipid based vesicles such as liposomes or niosomes (non-ionic surfactant vesicles) can be used as effective carriers of macromolecules (Bramwell and Perrie, 2006). Yet, many of these constructs can be destabilised after exposure to intestinal bile salts, which have the potential to cause the membrane deformation and vesicle lysis, resulting in the release of macromolecules from the vesicle prior to reaching its intended site of action.…”