Mishra Vivek, Mahor Sunil, Rawat Amit, Dubey Praveen, Gupta Prem N, Singh Paramjit, Vyas Suresh P
Drug Delivery Research Laboratory, Department of Pharmaceutical Sciences, Dr. Harisingh Gour Vishwavidyalaya, Sagar, Madhya Pradesh 470003, India.
Vaccine. 2006 Jul 7;24(27-28):5559-70. doi: 10.1016/j.vaccine.2006.04.030. Epub 2006 May 4.
Transcutaneous immunization (TCI) is a novel vaccination strategy based on the application of antigen together with an adjuvant onto hydrated bare skin. This simple and non-invasive immunization procedure elicits systemic and cell mediated immune responses and therefore, it provides a viable and cost-effective strategy for disease prevention. In the present study, novel fusogenic vesicular carrier constructs, i.e. vesosomes were developed and evaluated for topical delivery of vaccines using tetanus toxoid (TTx) as a model antigen. Prepared vesosomes were characterized for size, shape, entrapment efficiency and zeta potential. The prepared novel systems were examined for in process antigen stability and long-term storage stability studies. In vitro skin permeation and fluorescence microscopy study were also preformed for prepared novel vesicular systems for the evaluation of skin penetration efficiency. The immune stimulating activity of these vesicles was studied by measuring the serum anti-tetanus toxoid IgG titer and isotype ratio IgG2a/IgG1 following topical immunization in three different protocols and results were compared with the alum adsorbed tetanus toxoid given intramuscularly and topically administered plain tetanus toxoid solution, plain liposomes and cationic fusogenic liposomes. Serum IgG titers after three consecutive topical administrations were significantly better (*P < 0.05) than single administration of TTx antigen with vesosomal systems, suggesting an effective stimulation of serum immune response. Furthermore, notable serum anti-TTx antibody titers also occurred in animals primed with alum adsorbed TTx and subsequently boosted with topical administration of novel vesosomal systems. In each immunization studies, the vesosomal systems could elicit combined Th1 and Th2 immune responses following topical administration. These results suggest that the investigated vesosomal systems can be effective as topical delivery of vaccines.
经皮免疫（TCI）是一种基于将抗原与佐剂应用于湿润裸露皮肤的新型疫苗接种策略。这种简单且非侵入性的免疫程序可引发全身和细胞介导的免疫反应，因此，它为疾病预防提供了一种可行且具有成本效益的策略。在本研究中，开发了新型融合性囊泡载体构建体，即囊泡体，并使用破伤风类毒素（TTx）作为模型抗原对其进行疫苗局部递送评估。对制备的囊泡体进行了大小、形状、包封效率和zeta电位表征。对制备的新型系统进行了过程中抗原稳定性和长期储存稳定性研究。还对制备的新型囊泡系统进行了体外皮肤渗透和荧光显微镜研究，以评估皮肤渗透效率。通过在三种不同方案中局部免疫后测量血清抗破伤风类毒素IgG滴度和IgG2a/IgG1同种型比率，研究了这些囊泡的免疫刺激活性，并将结果与肌肉注射明矾吸附破伤风类毒素、局部给药普通破伤风类毒素溶液、普通脂质体和阳离子融合脂质体进行了比较。连续三次局部给药后的血清IgG滴度明显优于使用囊泡体系统单次给药的TTx抗原（*P < 0.05），表明对血清免疫反应有有效刺激。此外，在用明矾吸附TTx免疫并随后用新型囊泡体系统局部加强免疫的动物中也出现了显著的血清抗TTx抗体滴度。在每项免疫研究中，囊泡体系统在局部给药后均可引发Th1和Th2联合免疫反应。这些结果表明，所研究的囊泡体系统可作为疫苗局部递送有效。
