Single and repeat-dose toxicity and local tolerance assessment of newly developed oil emulsion adjuvant formulations for veterinary purposes.

Adjuvants are components of vaccines that boost the intensity, duration, and breadth of the immune response. Insight into the mechanisms responsible for the immunotoxicity of both local and systemic adverse reactions following the use of adjuvants has been gained through research over the past twenty years. In the present study, single and repeated-dose toxicity and local tolerance of newly developed Water-in-Oil (W/O) and Water-in-Oil-in-Water (W/O/W) Emulsion adjuvants (Coralvac RZ 528, Coralvac RZ 506, Coralvac AT 318, Coralvac AT 318 SIS and Coralvac 252) by Coral Biotechnology Industry and Trade Incorporated Company were demonstrated after intramuscular injection in mice. In both toxicity studies, no adverse reactions such as death, general appearance, behavior, or weight loss were observed in the mice in the experimental groups. The results indicate that clinical chemistry parameters demonstrated normal function of the major organs and no irreversible damage to the mice in all adjuvant groups compared to the control group. In histopathologic investigation of single dose toxicity study, inflammation, edema, and large amounts of lipid droplets were observed on the 7th day in all experimental groups. On the 14th day, when the control group and the experimental groups were compared, it was seen that inflammation and edema had decreased considerably. Similarly, repeated dose toxicity study showed mild inflammation and edema in the control group, while quite widespread and severe inflammation, edema, and diffuse lipid droplets of varying sizes were observed in all adjuvant groups compared to the control group. These observations would be useful for the future development of oil-based adjuvants and their use in veterinary inactive vaccines.

Synthesis, characterization and toxicity assessment of a new polymeric nanoparticle, l-glutamic acid-g-p(HEMA).

The toxic effects of poly(HEMA)-based polymeric nanoparticles must be analyzed before their biomedical applications as drug delivery systems. The aim of the study was to characterize and evaluate the toxicity for its biocompatibility of a newly synthesized l-glutamic acid-g-p(HEMA) polymeric nanoparticle The nanoparticle was synthesized with surfactant-free emulsion polymerization and grafting techniques. Grafting efficiency was estimated at 58%. The nanoparticle shape was verified as nearly spherical by scanning electron microscopy. Atomic force microscopy images showed a rough surface topography. The nanoparticle had an average size of ~194.6 nm on zeta analysis, and the zeta potential value was -18 mV. Fourier transformed infrared spectroscopy revealed spectra from 750 to 4000 cm-1 and characteristic peaks of stretching bands. The swelling ratio was 46%. With 24-h exposure, p(HEMA) and l-glutamic acid-g-p(HEMA) did not have cytotoxic effects on a human bronchial epithelial cell line (16HBE) and human monocyte cell line by water-soluble tetrazolium salt 1 (WST-1) assay and lactate dehydrogenase assay (LDH). It did not show genotoxic potential by comet assay and did not have mutagenic effects on Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains by Ames test. The nanoparticle at 160 µg/ml showed 2% hemolytic activity on erythrocytes. On cell migration assay, the percentage closure difference between exposed and control cells was estimated at 21%. We found no irritation effect on Hen's egg test-chorioallantoic membrane test. We determined that the polymeric nanoparticle l-glutamic acid-g-p(HEMA) was biocompatible and has potential for use in a drug delivery system.