Nanoscience Technology Center, Burnett School of Biomedical Sciences-College of Medicine, and Department of Chemistry, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, USA.
Mol Pharm. 2010 Aug 2;7(4):1209-22. doi: 10.1021/mp100043h.
The effective administration of therapeutic proteins has received increased attention for the treatment of various diseases. Encapsulation of these proteins in various matrices, as a method of protein structure and function preservation, is a widely used approach that results in maintenance of the protein's function. However, targeted delivery and tracking of encapsulated therapeutic proteins to the affected cells is still a challenge. In an effort to advance the targeted delivery of a functional apoptosis-initiating protein (cytochrome c) to cancer cells, we formulated theranostic polymeric nanoparticles for the simultaneous encapsulation of cytochrome c and a near-infrared dye to folate-expressing cancer cells. The polymeric nanoparticles were prepared using a novel water-soluble hyperbranched polyhydroxyl polymer that allows for dual encapsulation of a hydrophilic protein and an amphiphilic fluorescent dye. Our protein therapeutic cargo is the endogenous protein cytochrome c, which upon cytoplasmic release, initiates an apoptotic response leading to programmed cell death. Results indicate that encapsulation of cytochrome c within the nanoparticle's cavities preserved the protein's enzymatic activity. The potential therapeutic property of these nanoparticles was demonstrated by the induction of apoptosis upon intracellular delivery. Furthermore, targeted delivery of cytochrome c to folate-receptor-positive cancer cells was achieved via conjugation of folic acid to the nanoparticle's surface, whereas the nanoparticle's theranostic properties were conferred via the coencapsulation of cytochrome c and a fluorescent dye. Considering that these theranostic nanoparticles can carry an endogenous cellular apoptotic initiator (cytochrome c) and a fluorescent tag (ICG) commonly used in the clinic, their use and potential translation into the clinic is anticipated, facilitating the monitoring of tumor regression.
治疗性蛋白质的有效给药在治疗各种疾病方面受到了越来越多的关注。将这些蛋白质封装在各种基质中，作为一种保护蛋白质结构和功能的方法，是一种广泛使用的方法，可以保持蛋白质的功能。然而，将封装的治疗性蛋白质靶向递送到受影响的细胞仍然是一个挑战。为了推进功能性凋亡起始蛋白（细胞色素 c）向癌细胞的靶向递送，我们设计了用于同时封装细胞色素 c 和近红外染料到叶酸表达癌细胞的治疗诊断聚合物纳米粒子。该聚合物纳米粒子是使用一种新型水溶性超支化多羟基聚合物制备的，该聚合物允许同时封装亲水性蛋白质和两亲性荧光染料。我们的蛋白质治疗货物是内源性蛋白质细胞色素 c，其细胞质释放后，会引发凋亡反应，导致程序性细胞死亡。结果表明，纳米粒子腔室内的细胞色素 c 封装保留了蛋白质的酶活性。这些纳米粒子的潜在治疗特性通过细胞内递送至叶酸受体阳性癌细胞后诱导细胞凋亡得到证明。此外，通过将叶酸与纳米粒子表面缀合实现了细胞色素 c 对叶酸受体阳性癌细胞的靶向递送，而纳米粒子的治疗诊断特性则通过共封装细胞色素 c 和荧光染料来赋予。考虑到这些治疗诊断纳米粒子可以携带内源性细胞凋亡起始剂（细胞色素 c）和荧光标记物（ICG），它们在临床上的应用和潜在转化是可以预期的，这将有助于监测肿瘤的消退。
