Thyrotropin-Releasing Hormone Loaded and Chitosan Engineered Polymeric Nanoparticles: Towards Effective Delivery of Neuropeptides
作者:Sarabjit Kaur、Avani Bhararia、Krishna K Sharma、Sherry Mittal、Rahul Jain、Nishima Wangoo、Rohit K Sharma
DOI:10.1166/jnn.2016.12431
日期:2016.5.1
Thyrotropin-Releasing Hormone (TRH), a tripeptide amide with molecular formula L-pGlu-L-His-L-Pro-NH2, is used in the treatment of brain/spinal injury and certain central nervous system (CNS) disorders, including schizophrenia, Alzheimer’s disease, epilepsy, depression, shock and ischemia due to its profound effects on the CNS. However, TRH’s therapeutic activity is severely hampered because of instability and hydrophilicity owing to its peptidic nature which results into ineffective penetration into the blood brain barrier. In the present study, we report the synthesis and stability studies of novel chitosan engineered TRH encapsulated poly(lactide-co-glycolide) (PLGA) based nanoformulation. The aim of such an encapsulation is to allow effective delivery of TRH in biological systems as the peptidase degrade naked TRH. The synthesis of TRH was carried out manually in solution phase followed by its encapsulation using PLGA to form polymeric nanoparticles (NPs) via nanoprecipitation technique. Different parameters such as type of organic phase, concentration of stabilizer, ratio of organic phase and aqueous phase, rate of addition of organic phase were optimized, tested and evaluated for particle size, encapsulation efficiency, and stability of NPs. The TRH-PLGA NPs were then surface modified with chitosan to achieve positive surface charge rendering them potential membrane penetrating agents. PLGA, PLGA-TRH, Chitosan-PLGA and Chitosan-PLGA-TRH NPs were characterized and analyzed using Dynamic Light Scattering (DLS), Transmissiom Electron Microscopy (TEM) and Infra-red spectroscopic techniques.
促甲状腺激素释放激素(TRH)是一种三肽酰胺,分子式为 L-pGlu-L-His-L-Pro-NH2,因其对中枢神经系统(CNS)的深远影响,被用于治疗脑/脊髓损伤和某些中枢神经系统(CNS)疾病,包括精神分裂症、阿尔茨海默病、癫痫、抑郁症、休克和缺血。然而,TRH 的多肽性质导致其不稳定性和亲水性,从而无法有效渗透到血脑屏障中,严重影响了其治疗活性。在本研究中,我们报告了新型壳聚糖工程化 TRH 包封聚乳酸-共聚乙二醇(PLGA)纳米制剂的合成和稳定性研究。由于肽酶会降解裸TRH,因此这种封装的目的是在生物系统中有效地输送TRH。TRH 在溶液相中人工合成,然后使用 PLGA 通过纳米沉淀技术封装成聚合物纳米颗粒(NPs)。对有机相的类型、稳定剂的浓度、有机相与水相的比例、有机相的添加速率等不同参数进行了优化、测试和评估,以确定 NPs 的粒度、封装效率和稳定性。然后用壳聚糖对 TRH-PLGA NPs 进行表面修饰,使其表面带正电荷,从而使其成为潜在的膜渗透剂。使用动态光散射(DLS)、透射电子显微镜(TEM)和红外光谱技术对 PLGA、PLGA-TRH、壳聚糖-PLGA 和壳聚糖-PLGA-TRH NPs 进行了表征和分析。