Bioneedles as vaccine carriers.

Area of Science:

• Biomaterials Science
• Immunology
• Vaccine Technology

Background:

• Traditional vaccine delivery relies on needles and syringes.
• Challenges include needle-phobia, risk of infection, and antigen degradation during storage.

Purpose of the Study:

• To evaluate the stability and immunogenicity of tetanus toxoid formulated in bioneedles.
• To compare bioneedle delivery with conventional liquid injections.

Main Methods:

• Biodegradable polymer bioneedles were fabricated and filled with tetanus toxoid, with and without aluminum phosphate adjuvant.
• Stability was assessed by storing formulations at 60°C for up to 3 weeks.
• Immunogenicity was evaluated in mice by measuring antibody response after vaccination.

Main Results:

• Bioneedles preserved antigenicity at 60°C for 1 week, while liquid formulations lost all activity.
• A 60% antigen recovery was observed in bioneedles after 3 weeks at 60°C.
• Adjuvanted bioneedles induced comparable antibody responses to liquid injections but used four times less antigen.

Conclusions:

• Bioneedles demonstrate superior antigen stability compared to liquid formulations.
• Bioneedles represent a promising needle-free vaccine delivery system with enhanced efficacy and reduced antigen requirements.