Exposure to nanoplastics impairs collective contractility of neonatal cardiomyocytes under electrical synchronization.

Nanoplastics are global pollutants that have been increasingly released into the environment following the degradation process of industrial and consumer products. These tiny particles have been reported to adversely affect various organs in the body, including the heart. Since it is probable that the less-developed hearts of newborn offspring are more vulnerable to nanoplastic insult during the infant feeding compared with mature hearts of adults, the acute effects of nanoplastics on the collective contractility of neonatal cardiomyocytes are to be elucidated. Here, we traced the aggregation of nanoplastics on the cell membrane and their internalization into the cytosol of neonatal rat ventricular myocytes (NRVMs) for 60 min in the presence of electrical pulses to synchronize the cardiac contraction in vitro. The time-coursed linkage of collective contraction forces, intracellular Ca2+ concentrations, mitochondrial membrane potentials, extracellular field potentials, and reactive oxygen species levels enabled us to build up the sequence of the cellular events associated with the detrimental effects of nanoplastics with positive surface charges on the immature cardiomyocytes. A significant decrease in intracellular Ca2+ levels and electrophysiological activities of NRVMs resulted in the reduction of contraction forces in the early phase (0-15 min). The further reduction of contraction force in the late phase (30-60 min) was attributed to remarkable decreases in mitochondrial membrane potentials and cellular metabolism. Our multifaceted assessments on the effect of positively surface charged nanoplastics on NRVM may offer better understanding of substantial risks of ever-increasing nanoplastic pollution in the hearts of human infants or adults.

Surface Charge-Dependent Cytotoxicity of Plastic Nanoparticles in Alveolar Cells under Cyclic Stretches.

Polystyrene nanoparticles (PS-NPs) derived from both environmental and occupational sources are an important class of ultrafine particles associated with human pulmonary disorders. The effects of surface charges of particle internalization and toxicity to alveolar cells, especially under conditions comparable to those found during breathing, have not been examined. Here, we applied cyclic stretches (CS) to human alveolar cells during nanoparticle exposure and show an enhanced accumulation of positively charged polystyrene nanoparticles as compared to similar negatively charged particles. The cellular uptake of the positive particles into live cells was visualized with three-dimensional optical diffraction tomography (3-D ODT). The simultaneous application of both periodic stretching as well as positively charged nanoparticles led to blebbing morphology and activation of apoptotic signaling compared to control cells. Our findings provide a better understanding of how surface charge mediates the uptake and toxicity of nanoplastics under the dynamical mechanical conditions relevant for breathing exposures.

Clean approach to synthesis of graphene like CuFe2O4@polysaccharide resin nanohybrid: Bifunctional compound for dye adsorption and bacterial capturing.

Focus of this research is on employment of a green route to prepare magnetic CuFe2O4@polysaccharide resin for environmental remediation purpose. The method is including solvent free solid state synthesis of copper ferrite nanoparticles by combustion route using cellulose as fuel. Then polysaccharide resin as well as its magnetic composite was prepared by using glucose, citric acid and copper ferrite as solid raw materials. Characterization study using FESEM and TEM images showed that as synthesized resin possesses graphene like structure as ferrite nanoparticles are dispersed in the matrice of resin. Methylene blue (MB) adsorption study of the nanohybrid showed that maximum removal efficiency obtained at pH=8 with very fast equilibrium time of 1min. Kinetic study confirmed pseudo - second order model is dominant kinetic model for dye removal. Moreover isotherm study revealed dye adsorption followed Freundlich model with maximum adsorption capacity of 366.6mgg-1. Antibacterial activity of resin and magnetic composite was examined and result confirmed high efficiency of them in coping with E. coli as sample pathogen. Effect of solution pH, contact time and adsorbent dosage on E. coli capturing efficiency was also studied. Results showed bacteria capturing is more than 99% within equilibrium time of 20min and dosage of 20mg which confirmed high efficiency of the nanosystem in bacteria removing.