Perfluorocarbon induces alveolar epithelial cell response through structural and mechanical remodeling

Abstract

During total liquid ventilation, lung cells are exposed to perfluorocarbon (PFC) whose chemophysical properties highly differ from standard aqueous cell feeding medium (DMEM). We herein perform a systematic study of structural and mechanical properties of A549 alveolar epithelial cells in order to characterize their response to PFC exposure, using DMEM as control condition. Changes in F-actin structure, focal adhesion density and glycocalyx distribution are evaluated by confocal fluorescent microscopy. Changes in cell mechanics and adhesion are measured by multiscale magnetic twisting cytometry (MTC). Two different microrheological models (single Voigt and power law) are used to analyze the cell mechanics characterized by cytoskeleton (CSK) stiffness and characteristic relaxation times. Cell-matrix adhesion is analyzed using a stochastic multibond deadhesion model taking into account the non-reversible character of the cell response, allowing us to quantify the adhesion weakness and the number of associated bonds. The roles of F-actin structure and glycocalyx layer are evaluated by depolymerizing F-actin and degrading glycocalyx, respectively. Results show that PFC exposure consistently induces F-actin remodeling, CSK softening and adhesion weakening. These results demonstrate that PFC triggers an alveolar epithelial cell response herein evidenced by a decay in intracellular CSK tension, an adhesion weakening and a glycocalyx layer redistribution. These PFC-induced cell adjustments are consistent with the hypothesis that cells respond to a decrease in adhesion energy at cell surface. This adhesion energy can be even further reduced in the presence of surfactant adsorbed at the cell surface.

Periorbital Subcutaneous Perfluoron Is Well Tolerated Following Intravitreal Surgery

“…12 In addition to their high diffusion capacity, PFCLs' ability to fill the alveoli and displace edema led to their use as an inhaled drug-delivery system. 13,14 PFCLs have also been used as a blood substitute for patients in hemorrhagic shock or suffering from a variety of ischemic diseases. 15 When Stanley Chang reported the first ocular use of PFCLs for retinal detachment repair in 1987, these substances had been extensively studied and shown to be well tolerated with minimal inflammatory reactions elsewhere in the body.…”

Short-term effects of X-ray on viscoelastic properties of epithelial cells

“…27,28 Some studies determined the mechanical properties of cells after high-intensity radiation using atomic force microscopy (AFM) and concluded there was decreased stiffness after radiation, 29,30 while other studies have come to an opposite conclusion. 31,32 Different methods, such as micropipette aspiration, 33 AFM, 34 magnetic beads and tweezers and twisting, 35 have been utilized to determine the mechanical properties of cells, but relative incongruity exists in their results. Therefore, the mechanical properties of cells can be regarded as biomarkers that can be used in the diagnosis of some diseases and in the analysis of appropriate cell functioning.…”