Gaudana Ripal, Khurana Varun, Parenky Ashwin, Mitra Ashim K
Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA.
J Drug Deliv. 2011;2011:458128. doi: 10.1155/2011/458128. Epub 2011 Apr 27.
The objective of the present study is to formulate and characterize a nanoparticulate-based formulation of a macromolecule in a hydrophobic ion pairing (HIP) complex form. So far, HIP complexation approach has been studied only for proteins with molecular weight of 10-20 kDa. Hence, we have selected bovine serum albumin (BSA) having higher molecular weight (66.3 kDa) as a model protein and dextran sulphate (DS) as a complexing polymer to generate HIP complex. We have prepared and optimized the HIP complex formation process of BSA with DS. Ionic interactions between basic amino acids of BSA with sulphate groups of DS were confirmed by FTIR analysis. Further, nanoparticles were prepared and characterized with respect to size and surface morphology. We observed significant entrapment of BSA in nanoparticles prepared with minimal amounts of PLGA polymer. Finally, results of circular dichroism and intrinsic fluorescence assay have clearly indicated that HIP complexation and method of nanoparticle preparation did not alter the secondary and tertiary structures of BSA.
本研究的目的是制备并表征一种以疏水离子对（HIP）复合物形式存在的基于纳米颗粒的大分子制剂。到目前为止，HIP复合方法仅针对分子量为10 - 20 kDa的蛋白质进行了研究。因此，我们选择了分子量较高（66.3 kDa）的牛血清白蛋白（BSA）作为模型蛋白，并选择硫酸葡聚糖（DS）作为复合聚合物来生成HIP复合物。我们制备并优化了BSA与DS形成HIP复合物的过程。通过傅里叶变换红外光谱（FTIR）分析证实了BSA的碱性氨基酸与DS的硫酸基团之间的离子相互作用。此外，制备了纳米颗粒并对其尺寸和表面形态进行了表征。我们观察到，在使用最少量聚乳酸-羟基乙酸共聚物（PLGA）聚合物制备的纳米颗粒中，BSA有显著包封。最后，圆二色性和内源荧光测定结果清楚地表明，HIP复合以及纳米颗粒制备方法并未改变BSA的二级和三级结构。
