Powell Leagh G, Alexander Cameron, Stone Vicki, Johnston Helinor J, Conte Claudia
Nano Safety Research Group, School of Engineering and Physical Sciences, Heriot-Watt University UK.
Division of Molecular Therapeutics and Formulation, School of Pharmacy, University of Nottingham UK.
RSC Adv. 2022 Apr 27;12(20):12860-12870. doi: 10.1039/d2ra00395c. eCollection 2022 Apr 22.
It can be challenging to deliver drugs to cancer cells in a targeted manner at an effective dose. Polymeric nanoparticles (NPs) are promising drug delivery systems that can be targeted to cancer cells using redox responsive elements. More specifically, intracellular and extracellular levels of the antioxidant glutathione (GSH) are elevated in cancer cells and therefore the use of NPs with a cleavable GSH-responsive element allowing these NPs to target cancer cells and trigger the release of their cargo ( anticancer drugs). The aim of this study was to assess the hepatotoxicity of polymeric NP delivery systems with and without a redox sensitive element. Copolymer poly (lactic--glycolic acid) (PLGA) and polyethylene glycol (PEG) NPs with (RR-NPs) and without (nRR-NPs) a redox responsive dithiylethanoate ester linker were synthesised and their toxicity assessed . As the liver is a primary site of NP accumulation, the C3A hepatocyte cell line was used to assess NP toxicity investigation of cytotoxicity, cytokine production, genotoxicity, intracellular reactive oxygen species (ROS) production, intracellular calcium concentration, and hepatocyte function (albumin and urea production). The cellular uptake of NPs was also assessed as this may influence the cellular dose and, therefore, the cellular response. Both NPs had no detrimental impact on cell viability. However, both NPs stimulated an increase in cytokine (IL-1ra) and ROS production and decreased hepatocyte function, with the greatest effect observed for nRR-NPs. Only nRR-NPs caused DNA damage. Cells internalised both NPs and caused a (sub-lethal) increase in intracellular calcium levels. Therefore, whilst the NPs did not have a negative impact on cell viability, the NPs were able to elicit sub-lethal toxicity. By using a battery of tests we were able to demonstrate that RR-NPs may be less toxic than nRR-NPs. Our findings can therefore feed into the development of safer and more effective nanomedicines and into the design of testing strategies to assess polymeric NP safety based on knowledge of their mechanism of toxicity.
以有效剂量将药物靶向递送至癌细胞可能具有挑战性。聚合物纳米颗粒（NPs）是很有前景的药物递送系统，可利用氧化还原响应元件靶向癌细胞。更具体地说，癌细胞内和细胞外的抗氧化剂谷胱甘肽（GSH）水平升高，因此使用具有可裂解GSH响应元件的纳米颗粒，使这些纳米颗粒能够靶向癌细胞并触发其货物（抗癌药物）的释放。本研究的目的是评估具有和不具有氧化还原敏感元件的聚合物纳米颗粒递送系统的肝毒性。合成了具有（RR-NPs）和不具有（nRR-NPs）氧化还原响应二硫代乙醇酸酯连接子的共聚物聚（乳酸-乙醇酸）（PLGA）和聚乙二醇（PEG）纳米颗粒，并评估了它们的毒性。由于肝脏是纳米颗粒积累的主要部位，因此使用C3A肝细胞系来评估纳米颗粒毒性，研究细胞毒性、细胞因子产生、遗传毒性、细胞内活性氧（ROS）产生、细胞内钙浓度和肝细胞功能（白蛋白和尿素产生）。还评估了纳米颗粒的细胞摄取情况，因为这可能影响细胞剂量，进而影响细胞反应。两种纳米颗粒对细胞活力均无有害影响。然而，两种纳米颗粒均刺激细胞因子（IL-1ra）和ROS产生增加，并降低肝细胞功能，其中nRR-NPs的影响最大。只有nRR-NPs导致DNA损伤。细胞内化了两种纳米颗粒，并导致细胞内钙水平（亚致死性）升高。因此，虽然纳米颗粒对细胞活力没有负面影响，但纳米颗粒能够引发亚致死毒性。通过一系列测试，我们能够证明RR-NPs的毒性可能低于nRR-NPs。因此，我们的研究结果可为更安全、更有效的纳米药物开发以及基于纳米颗粒毒性机制知识的聚合物纳米颗粒安全性测试策略设计提供参考。
