Effective antigen delivery via dual entrapment in erythrocytes and autologous plasma beads

Abstract

Fibrin-based polymeric systems have now emerged as efficient carriers of drugs, growth factors, genes, and cells. Earlier, we have reported fibrin-based plasma beads (PB), prepared from clotted whole plasma, as an efficient system for the controlled release of entrapped therapeutics. In the present study, we investigate the dual entrapment in erythrocytes and PB, as potential particulate antigen delivery system in rabbit and mice, with yeast invertase as the model antigen. Preparations used for immunisation include- invertase entrapped in erythrocytes, the same further entrapped in PB, and crosslinked with glutaraldehyde. While route of administration of the antigen only moderately affected the antibody titres, strategies slowing its release from PB increased the antibody titres remarkably, especially after a booster. Entrapment of erythrocytes entrapped antigen in the PB and further crosslinking with glutaraldehyde also resulted in significant alterations of IgG1/IgG2a ratio, indicating a shift towards humoral response. The elicited immune response was more marked in rabbits as compared to that in mice. Considering the well-known toxicity of the adjuvant, comparable antibody titres induced by the erythrocyte-plasma bead system was encouraging in the induction of humoral immunity.

Keywords:

• Antigen
• adjuvant
• erythrocytes
• plasma beads
• invertase
• drug delivery

Acknowledgements

The entire work was carried out under the supervision of Prof. M. Saleemuddin, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh. The authors are highly grateful to him for his guidance and constant support. Authors were recipients of Senior Research Fellowship from Council of Scientific and Industrial Research (M.T.F.) and University Grants Commission (E.A. and M.H.) of Government of India. All the facilities provided by Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, are gratefully acknowledged.

Disclosure statement

The authors declare no conflicts of interest. The authors are solely responsible for the content and writing of this article.