Tiwari Shailja, Goyal Amit K, Khatri Kapil, Mishra Neeraj, Vyas Suresh P
Department of Pharmaceutical Sciences, Drug Delivery Research Laboratory, Dr Harisingh Gour Vishwavidyalaya, Sagar, MP, India.
J Microencapsul. 2009 Feb;26(1):75-82. doi: 10.1080/02652040802170897.
Many sub-unit vaccines are successful in preventing the occurrence of disease, but their use is largely restrained due to low immunogenicity. Novel carrier-based vaccine could serve as a vaccine adjuvant to overcome low immunogenicity of sub-unit vaccines. The use of liposomes as a delivery system for antigen is well recognized but they are unstable and release of antigen from them cannot be controlled over a prolonged period of time. To overcome the limitation of liposomes, this study has developed gel core liposomes in which a core of polymer was incorporated inside the liposomal vesicles, which serve the function of skeleton and provide mechanical strength to vesicles. In the present investigation BSA-loaded gel core liposomes were prepared by reverse phase evaporation method and characterized for vesicles size, shape, entrapment efficiency, in vitro release and stability studies. The in vivo studies to evaluate antigen presenting potential of the gel-core liposomes was performed in Balb/c mice by measuring the immune response elicited by intramuscular administration of BSA-loaded gel core liposomes and compared with intramuscularly administered BSA-loaded conventional liposomes, alum adsorbed BSA and plain antigen. Results indicate that intramuscular immunization with gel core liposomes induces efficient systemic antibody responses against BSA as compared to other formulations. The gel core liposomal formulation provides good entrapment efficiency, enhanced in vitro stability, prolonged antigen release and effective immunoadjuvant property, justifying its potential for improved vaccine delivery.
许多亚单位疫苗在预防疾病发生方面取得了成功，但由于免疫原性低，其应用受到很大限制。新型载体疫苗可作为疫苗佐剂，以克服亚单位疫苗免疫原性低的问题。脂质体作为抗原递送系统的应用已得到广泛认可，但它们不稳定，抗原从脂质体中的释放无法在较长时间内得到控制。为了克服脂质体的局限性，本研究开发了凝胶核心脂质体，其中在脂质体囊泡内部掺入了聚合物核心，该核心起到骨架的作用，并为囊泡提供机械强度。在本研究中，通过反相蒸发法制备了负载牛血清白蛋白（BSA）的凝胶核心脂质体，并对其囊泡大小、形状、包封率、体外释放和稳定性进行了表征。通过测量肌肉注射负载BSA的凝胶核心脂质体引发的免疫反应，并与肌肉注射负载BSA的传统脂质体、明矾吸附的BSA和单纯抗原进行比较，在Balb/c小鼠中进行了体内研究，以评估凝胶核心脂质体的抗原呈递潜力。结果表明，与其他制剂相比，肌肉注射凝胶核心脂质体可诱导针对BSA的高效全身抗体反应。凝胶核心脂质体制剂具有良好的包封率、增强的体外稳定性、延长的抗原释放和有效的免疫佐剂特性，证明了其在改善疫苗递送方面的潜力。
