Poly-DL-lactide-co-glycolide microspheres as a controlled release antigen delivery system

Abstract

Successful vaccine application means maximum protection with minimal number of administrations. A rational development of vaccines involves studies of the nature of the antigen as well as of the adjuvant to be used to improve the immune responses. This has provided the impetus for studies to design the degradable devices and for different approaches to antigen delivery by different routes of administration. The development of controlled release systems based on polymeric devices that permit a sustained or pulsed release of encapsulated antigens has attracted much interest. Polymeric delivery systems consist of polymers that release their content continuously in a controlled manner over a period of time. The development of a biocompatible delivery system for parenteral administration offers several advantages in terms of immunoadjuvanticity over other compounds. It was found that, in contrast to other carriers, microspheres are more stable, thus permitting administration by the oral or parenteral route. In the present study, we describe the main characteristics and potentialities of this new immunoadjuvant for oral and parenteral administration. Correspondence

Single dose of a vaccine based on DNA encoding mycobacterial hsp65 protein plus TDM-loaded PLGA microspheres protects mice against a virulent strain of Mycobacterium tuberculosis

“…However, DNA-loaded microspheres were also unable to protect mice against challenge. 16 This inability to confer protection against challenge could be associated with the reduction of the DNA amount administered and, consequently, the reduction of immunostimulatory CpG motifs. Immunomodulatory properties as induction of cytokine production and costimulatory molecules expression have been attributed to CpG motifs.…”

Chlamydia trachomatis recombinant MOMP encapsulated in PLGA nanoparticles triggers primarily T helper 1 cellular and antibody immune responses in mice: a desirable candidate nanovaccine

“…Biodegradable nanoparticles used as immune potentiators and delivery systems are now playing an increasing role in next-generation vaccine development projects. [36][37][38][39][40][41][42][43][44][45] Previously we showed that a PLGA-encapsulated rMOMP peptide induced Th1 responses in vitro which were potentiated by the presence of PLGA, 44 triggered expansion of T cell subsets and production of primarily rMOMP-specific Th1 cytokines in immunized mice; and sera from PLGA-rMOMP-immunized mice had increased levels of rMOMP-specific Th1 antibodies. One concern with encapsulating proteins in PLGA using the w/o/w emulsion is the generation of heat, which poses a major risk to proteins, and increases the chances of instability, degradation, and interaction with organic solvents.…”

“…[31][32][33][34][35] A promising alternative to using adjuvant is encapsulation of an immunogen in biodegradable polymers approved by the US Food and Drug Administration that release their contents over time. [36][37][38][39][40][41][42][43][44][45] Among the approved biodegradable polymers, poly D, L-lactide-co-glycolide (PLGA) nanoparticles have advantages that include enhancement of immune responses, delivery, biocompatibility and biodegradability, size, and sustained release. 38,43,44 Several studies have shown the efficiency of this release system when used to encapsulate other peptides, proteins, or DNA.…”

“…[36][37][38][39][40][41][42][43][44][45] Among the approved biodegradable polymers, poly D, L-lactide-co-glycolide (PLGA) nanoparticles have advantages that include enhancement of immune responses, delivery, biocompatibility and biodegradability, size, and sustained release. 38,43,44 Several studies have shown the efficiency of this release system when used to encapsulate other peptides, proteins, or DNA. [39][40][41][42][43][44] Additionally, a study by Champion et al showed the protective efficacy of MOMP in a vault nanoparticle.…”

“…38,43,44 Several studies have shown the efficiency of this release system when used to encapsulate other peptides, proteins, or DNA. [39][40][41][42][43][44] Additionally, a study by Champion et al showed the protective efficacy of MOMP in a vault nanoparticle. 46 The uniqueness of PLGA versus other biodegradable nanoparticles is that it undergoes nonenzymatic hydrolysis, resulting in two biological metabolic byproducts, namely lactic acid and glycolic acid.…”