Zhu Jing, Dong Xiaowei
Department of Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center.
Department of Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center;
J Vis Exp. 2017 May 22(123):55584. doi: 10.3791/55584.
The objective of this article is to introduce preparation and characterization methods for nerve growth factor (NGF)-loaded, high-density, lipoprotein (HDL)-mimicking nanoparticles (NPs). HDLs are endogenous NPs and have been explored as vehicles for the delivery of therapeutic agents. Various methods have been developed to prepare HDL-mimicking NPs. However, they are generally complicated, time consuming, and difficult for industrial scale-up. In this study, one-step homogenization was used to mix the excipients and form the prototype NPs. NGF is a water-soluble protein of 26 kDa. To facilitate the encapsulation of NGF into the lipid environment of HDL-mimicking NPs, protamine USP was used to form an ion-pair complex with NGF to neutralize the charges on the NGF surface. The NGF/protamine complex was then introduced into the prototype NPs. Apolipoprotein A-I was finally coated on the surface of the NPs. NGF HDL-mimicking NPs showed preferable properties in terms of particle size, size distribution, entrapment efficiency, in vitro release, bioactivity, and biodistribution. With the careful design and exploration of homogenization in HDL-mimicking NPs, the procedure was greatly simplified, and the NPs were made scalable. Moreover, various challenges, such as separating unloaded NGF from the NPs, conducting reliable in vitro release studies, and measuring the bioactivity of the NPs, were overcome.
本文的目的是介绍用于负载神经生长因子（NGF）的高密度脂蛋白（HDL）模拟纳米颗粒（NPs）的制备和表征方法。HDL是内源性纳米颗粒，已被探索用作治疗剂递送的载体。已经开发了各种方法来制备HDL模拟纳米颗粒。然而，它们通常很复杂、耗时且难以进行工业放大生产。在本研究中，采用一步均质化来混合辅料并形成原型纳米颗粒。NGF是一种26 kDa的水溶性蛋白质。为了便于将NGF封装到HDL模拟纳米颗粒的脂质环境中，使用了美国药典鱼精蛋白与NGF形成离子对复合物，以中和NGF表面的电荷。然后将NGF/鱼精蛋白复合物引入原型纳米颗粒中。最后在纳米颗粒表面包被载脂蛋白A-I。NGF HDL模拟纳米颗粒在粒径、粒径分布、包封率、体外释放、生物活性和生物分布方面表现出较好的性能。通过对HDL模拟纳米颗粒中均质化的精心设计和探索，该过程大大简化，并且纳米颗粒可实现规模化生产。此外，还克服了各种挑战，如从纳米颗粒中分离未负载的NGF、进行可靠的体外释放研究以及测量纳米颗粒的生物活性。
