Salman Hesham H, Gamazo Carlos, de Smidt P Chris, Russell-Jones Gregory, Irache Juan M
Centro Galénico, University of Navarra, Pamplona, Spain.
Pharm Res. 2008 Dec;25(12):2859-68. doi: 10.1007/s11095-008-9657-5. Epub 2008 Aug 5.
To design bioadhesive Gantrez AN (poly[methyl vinyl ether-co-maleic anhydride], PVM/MA) nanoparticles (NP) coated with vitamin B(12) (Vit B(12)), and investigate their application in oral antigen delivery.
The association of Vit B(12) to Gantrez AN nanoparticles was performed by the direct attachment of reactive Vit B(12) to the surface of the nanoparticles (NPB), or linking to the copolymer chains in dimethylformamide prior to NP formation (NPB-DMF). Nanoparticles were characterized by measuring the size, zeta potential, Vit B(12) association efficacy, and stability of Vit B(12) on the surface of the nanoparticles. In vivo bioadhesion study was performed by the oral administration of fluorescently-labeled nanoparticle formulations to rats. Both systemic and mucosal immune responses were evaluated after oral and subcutaneous immunization with ovalbumin (OVA) containing Vit B(12)-coated nanoparticles.
The Vit B(12) nanoparticles displayed homogenous size distribution with a mean diameter of about 200 nm and a negative surface charge. The association efficiency of Vit B(12) to NPB-DMF formulation was about two times higher than to the NPB, showing also a higher surface stability of Vit B(12). The bioadhesion study demonstrated that NPB-DMF had an important tropism to the distal portions of the gut, which was about two and 3.5 times higher than the tropism observed for NPB and control NP, respectively (p < 0.05). Oral administration of OVA-NPB-DMF induced also stronger and more balanced serum anti-OVA titers of IgG2a (Th1) and IgG1 (Th2) compared to control OVA-NP. In addition, oral immunization with OVA-NPB-DMF induced a higher mucosal IgA response than subcutaneous administration.
These results indicate the benefits of bioadhesive Vit B(12)-coated nanoparticles in oral antigen delivery eliciting systemic and mucosal immune response.
设计用维生素B12（Vit B12）包被的生物黏附性甘膦树脂AN（聚[甲基乙烯基醚-顺丁烯二酸酐]，PVM/MA）纳米颗粒（NP），并研究其在口服抗原递送中的应用。
通过将活性Vit B12直接附着于纳米颗粒表面（NPB），或在纳米颗粒形成之前在二甲基甲酰胺中与共聚物链连接（NPB-DMF），使Vit B12与甘膦树脂AN纳米颗粒结合。通过测量纳米颗粒的大小、ζ电位、Vit B12结合效率以及Vit B12在纳米颗粒表面的稳定性来对纳米颗粒进行表征。通过给大鼠口服荧光标记的纳米颗粒制剂进行体内生物黏附研究。在用含Vit B12包被纳米颗粒的卵清蛋白（OVA）进行口服和皮下免疫后，评估全身和黏膜免疫反应。
Vit B12纳米颗粒呈现均匀的大小分布，平均直径约为200 nm，表面带负电荷。Vit B12与NPB-DMF制剂的结合效率比与NPB的结合效率高约两倍，同时Vit B12在表面也具有更高的稳定性。生物黏附研究表明，NPB-DMF对肠道远端部分具有重要的趋向性，分别比NPB和对照NP观察到的趋向性高约两倍和3.5倍（p<0.05）。与对照OVA-NP相比，口服OVA-NPB-DMF还诱导产生更强且更平衡的IgG2a（Th1）和IgG1（Th2）血清抗OVA滴度。此外，用OVA-NPB-DMF进行口服免疫诱导的黏膜IgA反应比皮下给药更高。
这些结果表明生物黏附性Vit B12包被纳米颗粒在引发全身和黏膜免疫反应的口服抗原递送中具有优势。
