Cytotoxicity of Calcium Rectorite Micro/Nanoparticles before and after Organic Modification

Abstract

Organically modified rectorite (OREC) micro/nanoparticles can be synthesized by organic modification from calcium rectorite (Ca(2+)-REC or REC), a common form of rectorite in nature. Although REC and OREC have potential applications in food packing and drug delivery, their cytotoxicity is not clear. In the present study, we investigated and compared the cytotoxicity of REC and OREC micro/nanoparticles in Chang liver cells, the human normal hepatic cells, and human hepatoma HepG2 cells. The interlayer spacing of OREC was enlarged after organic modification. After treatment with REC or OREC for 24 h at 1 and 5 μg/mL, they were taken up by Chang liver cells. REC and OREC induced cytotoxicity in Chang liver and HepG2 cells at almost all doses (1, 2.5, 5, 7.5, and 10 μg/mL) after 6, 24, and 48 h of treatment (P < 0.05 or P < 0.01). Compared with REC, OREC was more cytotoxic. However, there was no difference in the cytotoxicity of REC and OREC between the two cell lines. After treatment with REC or OREC at 7.5 and 10 μg/mL for 24 h, the apoptotic and necrotic percentages of Chang liver cells were increased (P < 0.05 or P < 0.01). The levels of apoptosis-related proteins Bax, Bcl-2, and pro-caspase-3 were all decreased in Chang liver cells after 24 h of exposure to REC or OREC at 5, 7.5, 10 μg/mL. There was no change in the relative ratio of Bax/Bcl-2 after treatment, indicating that REC or OREC-induced apoptosis was not associated with Bax-related mitochondria-mediated apoptotic pathway. Our results suggested that OREC was more cytotoxic than REC, but the underlying mechanisms need further investigation.

Enhanced tumor targeting effects of a novel paclitaxel-loaded polymer: PEG–PCCL-modified magnetic iron oxide nanoparticles

“…The average size results of these two polymers indicated that they were blood vessels permeable. The test was repeated with the same solution two weeks later, and similar size distributions were detected, which suggested that conditions of PEG–PCCL and PEG–PCCL-MNP were relatively stable in the solution (Liu et al., 2014 ). The PDI values, as an important measure of the width of molecular weight distributions (MWD) (Rogošić et al., 1996 ), of both our nanoparticles were relatively low, indicating that they had a relatively mean nanoparticle size.…”

“…The PDI values, as an important measure of the width of molecular weight distributions (MWD) (Rogošić et al., 1996 ), of both our nanoparticles were relatively low, indicating that they had a relatively mean nanoparticle size. The zeta potential of PEG–PCCL-MNP was less than that of PEG–PCCL, representing that PEG–PCCL-MNP had a higher nanoparticle stability from aggregation (Liu et al., 2014 ). The EE PTX in both PEG–PCCL-MNP/PTX and PEG–PCCL/PTX was over 50%.…”

Presence of nano-sized chitosan-layered silicate composites protects against toxicity induced by lead ions

“…The average diameter of the REC and OREC was 458.3 ± 26.2 and 243.7 ± 16.9 nm according our previous investigation (Liu et al, 2014). In CS-OREC composites, the initial weight ratio of CS: OREC was adjusted at 6:1.…”

“…It was reported that the addition of bentonite with levels 1 or 2% to alleviate the toxic effects of lead oxide contaminated dietary for O. niloticus fish (Farrag et al, 2009). Based on our recent reports, rectorite (REC), especially organic rectorite (OREC) modified from REC, had larger interlayer distance, better separable layer thickness and layer aspect ratio than montmorillonite (MMT), and the toxicity of OREC was little (Liu, Deng, Xiao, Xie, & Zhou, 2014). Since CS chains could insert into the interlayer of REC and OREC, resulting much larger interlayer distance (Wang et al, 2007).…”

Assembly of Layered Silicate Loaded Quaternized Chitosan/Reduced Graphene Oxide Composites as Efficient Absorbents for Double-Stranded DNA

“…Layered silicates, natural minerals with large surface area and chemical and mechanical stability, are known to be potentially useful as supports for dispersed semiconductor particles, metals, and metal oxides . Rectorite (REC) is a similar mineral resource layered structure with montmorillonite, which can also display a stabilizing effect. , It is noted that its interlayer distance is larger than that of montmorillonite, and after modifying by surfactants, the obtained organic rectorite (OREC) has a larger interlayer distance than REC. , However, until now, there is no report on stabilizing rGO with REC or OREC.…”