Department of Biochemistry, Sathyabama Dental College and Hospitals, Sathyabama University, Rajiv Gandhi Salai, Sholinganallur, Chennai 119, Tamilnadu, India.
Colloids Surf B Biointerfaces. 2013 Jan 1;101:126-34. doi: 10.1016/j.colsurfb.2012.06.019. Epub 2012 Jun 28.
Designing novel materials for biomedical applications generally require the use of biodegradable materials. This study aims to engineer a biodegradable [chitosan (CS) and poly (lactic acid) (PLA)] as AQ carrier with nanometer dimensions and to evaluate the anticancer potency of the prepared CS/PLA-AQ NPs in human carcinoma (HepG2) cells. CS-PLA complex, which are well dispersed and stable in aqueous solution, was prepared by the precipitation of lactic acid in chitosan solution by dropping method and characterized by SEM, TEM, DLS and FTIR. The results thus displayed that the prepared nanoparticles carried a positive charge and showed the size in the range from 100 to 200 nm. The in vitro (AQ) release study showed that these nanoparticles provided a continuous release of the entrapped AQ for 10 days, and the release behavior was influenced by the pH value of the medium thereby making feasible to develop CS-PLA for enhanced and sustained release of AQ. MTT assay revealed higher cytotoxic efficacy of CS/PLA-AQ NPs than Free AQ in HepG2 cells. Further, the mitochondrial membrane damage indicated by loss of mitochondrial membrane potential and necrotic cell death could be attributed to the increased reactive oxygen species production. Our results also suggest that upon CS/PLA-AQ NPs exposure the cell viability decreased due to apoptosis, as demonstrated by the formation of apoptotic bodies, sub-G1 hypodiploid cells, and DNA fragmentation. Henceforth, CS/PLA-AQ NPs demonstrated a strong antitumor activity in vitro by reducing cell viability, inducing cell necrosis, decreasing the negative surface charge and mitochondrial membrane potential, and fragmenting DNA.
为了满足生物医学应用的需求，通常需要设计新型的可生物降解材料。本研究旨在设计一种具有纳米尺寸的可生物降解的[壳聚糖（CS）和聚乳酸（PLA）]作为AQ 载体，并评估所制备的 CS/PLA-AQ NPs 在人肝癌（HepG2）细胞中的抗癌功效。通过滴加法将乳酸沉淀在壳聚糖溶液中，制备出在水溶液中具有良好分散性和稳定性的 CS-PLA 复合物，并通过 SEM、TEM、DLS 和 FTIR 进行了表征。结果表明，所制备的纳米颗粒带正电荷，尺寸在 100-200nm 范围内。体外（AQ）释放研究表明，这些纳米颗粒可在 10 天内持续释放包封的 AQ，并且释放行为受介质 pH 值的影响，因此可以开发 CS-PLA 以增强和持续释放 AQ。MTT 分析表明，与游离 AQ 相比，CS/PLA-AQ NPs 在 HepG2 细胞中具有更高的细胞毒性。此外，线粒体膜电位的丧失和坏死性细胞死亡表明线粒体膜损伤可能归因于活性氧（ROS）的产生增加。我们的结果还表明，由于细胞凋亡，CS/PLA-AQ NPs 暴露后细胞活力降低，这表现为凋亡小体的形成、亚 G1 亚二倍体细胞和 DNA 片段化。因此，CS/PLA-AQ NPs 通过降低细胞活力、诱导细胞坏死、降低负表面电荷和线粒体膜电位以及片段化 DNA，在体外表现出很强的抗肿瘤活性。
