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[The morphology of the micro-capsulated polyacrylic acid-based formulation of measles vaccine]
Abstract:
The morphology and virus localization were studied in the microcapsulated measles vaccine formulation involving polyacrylic acid (PAA) copolymers as a matrix. Transmission electron microscopy and phosphotungsic staining at a pH value of 2 to 7 showed that the morphology of microparticles was related to the value of pH and to the concentration of a polymer in the matrix. In the neutral medium, the microcapsules had the sizes of 0.5 to 10 microm, which were optimal for transport through the intestinal wall when immunization was orally used. Immunocytochemistry revealed measles virus antigen within the microparticles. The specific activity of the microcapsulated formulation of measles virus was as high as 3.36 and 4.31 lg of TCD50/0.5 ml for the samples containing 1 and 0.1% polymer, respectively. The findings suggest that the microparticles of the vaccine contain live measles virus.
Insights
This study shows that measles vaccine microparticles, using polyacrylic acid (PAA) copolymers, maintain live virus and optimal size for oral delivery. These findings support the potential of microencapsulated vaccines for improved immunization strategies.
Area of Science:
- Vaccine development
- Materials science
- Virology
Background:
- Microencapsulation is a promising technique for oral vaccine delivery.
- Polyacrylic acid (PAA) copolymers offer potential as matrices for vaccine formulations.
- Understanding microparticle morphology and virus integrity is crucial for vaccine efficacy.
Purpose of the Study:
- To investigate the morphology and virus localization within microencapsulated measles vaccine formulations.
- To determine the influence of polyacrylic acid (PAA) concentration and pH on microparticle characteristics.
- To assess the suitability of microcapsules for oral immunization.
Main Methods:
- Transmission electron microscopy (TEM) with phosphotungstic acid staining.
- Immunocytochemistry to detect measles virus antigen.
- Evaluation of microparticle size and morphology at varying pH and polymer concentrations.
Main Results:
- Microparticle morphology is dependent on pH and PAA concentration.
- Optimal microcapsule size (0.5-10 µm) achieved in neutral pH for intestinal transport.
- Measles virus antigen confirmed within microparticles, indicating live virus presence.
- High specific activity (3.36-4.31 lg TCD50/0.5 ml) observed in microencapsulated formulations.
Conclusions:
- Microparticles formulated with PAA copolymers effectively encapsulate live measles virus.
- The microencapsulation process yields particles with characteristics suitable for oral delivery.
- This microencapsulated measles vaccine formulation shows high specific activity and potential for effective immunization.
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