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[Immunogenicity of single-dose HBsAg-PLGA controlled release microspheres in mice]
Li Feng1, Xing-jun Zhou, Shi-cong Wang
1Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China.
Aim:
To investigate the level of immune response and the immune mechanism of the single-dose hepatitis B surface antigen (HBsAg)-poly (d, l)-lactide-co-glicolide acid (PLGA) microspheres in BALB/c mice.
Methods:
Three kind of HBsAg-PLGA microspheres, HBsAg-PLGA50/50-COOH microspheres, HBsAg-PLGA75/25 microspheres and HBsAg-PLGA50/50 microspheres, were prepared by double emulsion microencapsulation technique used three kinds of PLGA with different L/G ratio. The single-dose of HBsAg-PLGA microspheres was subcutaneously injected into BALB/c mice at the dose of 7.5 microg HBsAg per mouse. The conventional aluminum-adjuvant vaccine was subcutaneously injected at 0, 1 and 2 month as positive control. In certain time interval, the induced immune level of total antibody was detected by enzyme linked immunosorbent assay (ELISA). For subclass of IgG antibody and cytokines studies, the dose of HBsAg was 2.5 microg per mouse.
Results:
The HBsAg-PLGA microspheres could successfully induce a humoral immune response in BALB/c mice. Compared with the conventional aluminum-adjuvant vaccine, the antibody response of the HBsAg-PLGA50/50-COOH microspheres was significantly lower than the group received three injections of aluminum-adjuvant vaccine (P < 0.01) except for a higher priming response during the early 6 weeks. The results were ascribed to the relatively rapid degradation charactics of PLGA50/50-COOH polymer. The immune response for the HBsAg-PLGA50/50 microspheres and HBsAg-PLGA75/25 microspheres were comparable to the group administered with aluminum-adjuvant vaccine (P > 0.05) which was due to the sustained degradation of PLGA50/50 and PLGA75/25 polymer.
Conclusion:
The HBsAg-PLGA microsphere is a promising candidate for the controlled delivery of a vaccine which does not require multiple injections.
Insights
Single-dose hepatitis B surface antigen (HBsAg)-poly (d, l)-lactide-co-glicolide acid (PLGA) microspheres induced a humoral immune response in mice. Certain PLGA microspheres showed comparable antibody responses to conventional vaccines, suggesting potential for single-injection vaccine delivery.
Area of Science:
- Biotechnology
- Immunology
- Materials Science
Background:
- Hepatitis B remains a significant global health concern.
- Conventional hepatitis B vaccines require multiple doses for optimal efficacy.
- Poly (d, l)-lactide-co-glicolide acid (PLGA) microspheres offer potential for controlled drug and vaccine delivery.
Purpose of the Study:
- To evaluate the immune response and mechanism of single-dose hepatitis B surface antigen (HBsAg)-PLGA microspheres in BALB/c mice.
- To compare the immunogenicity of different HBsAg-PLGA formulations.
- To assess the potential of HBsAg-PLGA microspheres as a single-injection vaccine candidate.
Main Methods:
- Three types of HBsAg-PLGA microspheres (HBsAg-PLGA50/50-COOH, HBsAg-PLGA75/25, HBsAg-PLGA50/50) were prepared using double emulsion microencapsulation.
- Mice were subcutaneously injected with a single dose of HBsAg-PLGA microspheres (7.5 microg HBsAg) or a conventional aluminum-adjuvant vaccine (control).
- Humoral immune response, including total antibody levels and IgG subclasses, was assessed via ELISA at specific time points.
Main Results:
- HBsAg-PLGA microspheres successfully induced a humoral immune response in mice.
- HBsAg-PLGA50/50-COOH microspheres showed a lower antibody response compared to the aluminum-adjuvant vaccine, attributed to rapid polymer degradation.
- HBsAg-PLGA50/50 and HBsAg-PLGA75/25 microspheres elicited comparable immune responses to the aluminum-adjuvant vaccine, due to sustained polymer degradation.
Conclusions:
- HBsAg-PLGA microspheres are a viable platform for controlled vaccine delivery.
- Certain PLGA formulations can elicit robust immune responses comparable to conventional vaccines.
- HBsAg-PLGA microspheres represent a promising strategy for single-injection hepatitis B vaccination.
