A Needle-Free Approach for Topical Immunization: Antigen Delivery via Vesicular Carrier System(s)

Abstract

Topical immunization (TI) is novel and needle free strategy involving vaccine delivery through topical application of antigen and adjuvant(s) directly or via a suitable carrier system on intact skin. Anatomy and physiology of skin attracts scientists in developing topical carrier system(s) for enhanced delivery of bioactive(s). Numerous techniques i.e. physical, chemical and vesicular carrier systems have been exploited for topical immunization. The present review discuss various vesicular systems i.e. liposomes, niosomes, transfersomes, vesosomes etc. for the efficient topical delivery of various immunogens along with comparative points of their merit(s) in TI. The mechanism of permeation of bioactive(s) through skin route via these carriers to the immune system for development of both cellular and humeral immunity has also been discussed. Moreover, the effect of composition and type of carrier system on type of immunity induced has also been focused to develop new effective carrier system(s) for topical immunization.

Progress Towards a Needle-Free Hepatitis B Vaccine

“…According to Mahor, topical immunization (TI), or transcutaneous immunization (TCI), is a novel and needle-free strategy involving vaccine delivery through topical application of antigen and adjuvant(s) directly or via a suitable carrier system on intact skin (131). The skin is a complicated structure, made up of several layers.…”

“…Even though it is possible to induce an immune response using naked DNA, it has been proven that its uptake by APC is minimal. Also, naked DNA is vulnerable to hydrolysis by enzymes present in the interstitial space and therefore needs to be protected, thus making vesicular carriers an even more appealing approach (131).…”

“…Niosomes can be used as topical carriers for immunoagents aiming at transdermal delivery (21). They are considered a better alternative to liposomes because they are cheap, highly pure, uniform in content, very stable and easy to store (21,131).…”

“…Ethosomes are novel and attractive vesicular carriers for topical immunization that were first developed by Touitou et al (157). Essentially, they are lipid vesicles with a high content of ethanol (131), which is a well-known permeation enhancer, since it fluidizes both lipid and bilayer of the stratum corneum, allowing a more effective delivery of active substances through the skin than conventional liposomes (131,158,159).…”

Advances in Effective Vaccine Development Against Hepatitis B: Focus on Mucosal Vaccine Delivery Strategies

“…The skin acts as an active immune surveillance organ that is rich in very dynamic antigen-presenting dendritic cells and Langerhan's cells found in the epidermis and the immature dendritic cells of the dermis [60]. The noninvasive topical vaccination can be affected using suitable carriers such as liposomes, niosomes, virosomes and nanoparticles, or naked DNA in solution using a gene gun.…”