Toxicology Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojapura, Trivandrum, 695 012, Kerala, India.
Toxicology Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojapura, Trivandrum, 695 012, Kerala, India.
Environ Res. 2020 Sep;188:109716. doi: 10.1016/j.envres.2020.109716. Epub 2020 May 26.
Fullerene comprises the major allotrope of carbon holding several fruitful potentials to be applied in various industrial and biomedical scenarios. Scientists have acquired large number of data on fullerene research using its derivatives like C60, C70 etc. Nevertheless, a precise focus on fullerene soot nanopaticles and its toxic impacts in living tissue is still behind mainstay even if it represents the crude parent form of all other derivatives. Present study addresses an acute toxicity profiling of fullerene soot nanoparticles in alveolar epithelial cells (A549) as a paradigm of pulmonary exposure. Surface functionalization was given for fullerene soot nanoparticles using dextran polymer as a mean to establish a stable homogenous dispersion (denoted as dFSNPs hereafter). Following functionalization, dFSNPs were characterized for various parameters including size, surface charge, morphology and functional groups using DLS, Zeta potential analysis, TEM and FT-IR measurements respectively. Effective dextran functionalization was evident from the characteristic peaks in FTIR spectra. Cell viability assessed using MTT and NRU assays; both of which showed a dose dependent cytotoxic response. Thymidine incorporation also confirmed similar trend in viability rate. In accordance with literatures, DCFHDA assay confirmed free radical scavenging activity of fullerene nanoparticles. An altered cellular morphology was observed under fluorescent microscope. Sub-cellular functionalities including lysosomal integrity and mitochondrial stability were found to be compromised at highest tested concentration of dFSNPs (160 μg/ml) without any genotoxic impacts within nuclear premises. FACS analysis following Annexin-PI staining confirmed apoptotic cell death. Hence the overall study substantiated dose dependent toxicity of dFSNPs which is likely to occur during pulmonary exposure.
富勒烯是碳的主要同素异形体，具有多种潜在的应用前景，可应用于各种工业和生物医学领域。科学家们已经获得了大量关于富勒烯研究的数据，包括其衍生物 C60、C70 等。然而，对于富勒烯烟尘纳米颗粒及其在活组织中的毒性影响的精确关注仍然落后于主流，即使它代表了所有其他衍生物的原始母体形式。本研究以肺泡上皮细胞（A549）为模型，研究了富勒烯烟尘纳米颗粒的急性毒性特征。通过使用葡聚糖聚合物对富勒烯烟尘纳米颗粒进行表面功能化，建立了稳定的均相分散体（以下简称 dFSNPs）。功能化后，通过 DLS、Zeta 电位分析、TEM 和 FT-IR 测量分别对 dFSNPs 的粒径、表面电荷、形态和官能团进行了表征。FTIR 光谱中的特征峰表明，葡聚糖的功能化是有效的。使用 MTT 和 NRU 测定法评估细胞活力，结果均显示出剂量依赖性的细胞毒性反应。胸苷掺入也证实了存活率的相似趋势。根据文献，DCFHDA 测定法证实了富勒烯纳米颗粒的自由基清除活性。在荧光显微镜下观察到细胞形态发生改变。在最高测试浓度（160μg/ml）下，亚细胞功能包括溶酶体完整性和线粒体稳定性受到损害，但在核内没有任何遗传毒性影响。用 Annexin-PI 染色进行 FACS 分析证实了细胞凋亡。因此，总的来说，本研究证实了 dFSNPs 的剂量依赖性毒性，这种毒性可能发生在肺部暴露期间。
