Memory antibody response from antigen loaded polymer particles and the effect of antigen release kinetics

Retention of structure, antigenicity, and biological function of pneumococcal surface protein A (PspA) released from polyanhydride nanoparticles

“…The encapsulation of PspA into polyanhydride nanoparticles provided a number of benefits over using off-the-shelf adjuvants such as MPLA, including sustained release, long-lasting immune responses, and higher avidity antibodies, as demonstrated previously with other protein antigens [32, 53]. Because PspA was found to be structurally stable, antigenic, and biologically functional upon release from two separate polyanhydride nanoparticle chemistries, there exists the ability to rationally select nanoparticle formulations to protect vaccine antigens while tailoring the immune response to a phenotype that is most effective against S. pneumoniae .…”

“…The single dose administration of particles based on biodegradable polymers such as polyanhydrides has demonstrated the ability to provide antibody titers consistent with those induced by multiple doses of traditional adjuvants [52]. Continuous release of antigen would mimic a replicating pathogenic infectious agent and generates a robust, long-lasting immune response as the continual exposure of B cells to antigen induces a strong memory response [53]. Additionally, the initial burst of released antigen observed with both the 20:80 CPH:SA and 50:50 CPTEG:CPH nanoparticle formulations may provide sufficient antigen to successfully prime the immune response and generate T cell help.…”

A single dose biodegradable vaccine depot that induces persistently high levels of antibody over a year

“…Nonetheless and despite reports of diminishing antibody titres in some of these studies, secondary responses have been effectively recalled upon re-exposure to antigen [5,13] indicating that some of the approaches have the capability to establish immunological memory. Although these approaches might represent an advance over multiple dosing regimens, the need to recall responses through antigen re-exposure is unlikely to be effective against, for example, pathogens that harbour concealed antigens.…”

Biodegradable polymers for modern vaccine development

“…PLA is another important synthetic biopolymer that exist as different isomers; poly(L-lactic acid) and poly(D-lactic acid) have been studied in the context of vaccine development [17]. An earlier study reported an enhancement in memory antibody response upon immunization with a single dose of tetanus toxin (TT)-or diphtheria toxin (DT)loaded PLA particles [31]. PLA has been used for the preparation of microcapsules, microspheres, and nanospheres and is usually designed to achieve either controlled or pulsed release over a prolonged period [17].…”