Elasticity and adhesion of resting and lipopolysaccharide‐stimulated macrophages

et al. 2012

Sci. China Life Sci.

Mechanical properties play an important role in regulating cellular activities and are critical for unlocking the mysteries of life. Atomic force microscopy (AFM) enables researchers to measure mechanical properties of single living cells under physiological conditions. Here, AFM was used to investigate the topography and mechanical properties of red blood cells (RBCs) and three types of aggressive cancer cells (Burkitt's lymphoma Raji, cutaneous lymphoma Hut, and chronic myeloid leukemia K562). The surface topography of the RBCs and the three cancer cells was mapped with a conventional AFM probe, while mechanical properties were investigated with a micro-sphere glued onto a tip-less cantilever. The diameters of RBCs are significantly smaller than those of the cancer cells, and mechanical measurements indicated that Young's modulus of RBCs is smaller than those of the cancer cells. Aggressive cancer cells have a lower Young's modulus than that of indolent cancer cells, which may improve our understanding of metastasis. atomic force microscopy, red blood cell, cancer cell, mechanical properties, Young's modulus Citation:Li M, Liu L Q, Xi N, et al. Atomic force microscopy imaging and mechanical properties measurement of red blood cells and aggressive cancer cells. Sci China Life Sci, 2012, 55: 968 -973,

Section: Resultssupporting

confidence: 78%

Atomic force microscopy imaging and mechanical properties measurement of red blood cells and aggressive cancer cells

et al. 2012

Sci. China Life Sci.

“…57 For macrophages, research has showed that the Young's modulus of macrophages was in the range of 0.5−2 kPa. 58 Recent research showed that the cell mechanical properties determined the macrophage functions. 59 Here the measured Young's modulus of macrophages was in the range of 1−3 kPa and became 2−5 kPa after the activation of phagocytosis, comparable to the measured values of the cell Young's modulus by other groups.…”

Section: Resultsmentioning

confidence: 99%

Nanoscale Imaging and Mechanical Analysis of Fc Receptor-Mediated Macrophage Phagocytosis against Cancer Cells

et al. 2014

Langmuir

Fc receptor-mediated macrophage phagocytosis against cancer cells is an important mechanism in the immune therapy of cancers. Traditional research about macrophage phagocytosis was based on optical microscopy, which cannot reveal detailed information because of the 200-nm-resolution limit. Quantitatively investigating the macrophage phagocytosis at micro-and nanoscale levels is still scarce. The advent of atomic force microscopy (AFM) offers an excellent analytical instrument for quantitatively investigating the biological processes at single-cell and singlemolecule levels under native conditions. In this work, we combined AFM and fluorescence microscopy to visualize and quantify the detailed changes in cell morphology and mechanical properties during the process of Fc receptor-mediated macrophage phagocytosis against cancer cells. Lymphoma cells were discernible by fluorescence staining. Then, the dynamic process of phagocytosis was observed by time-lapse optical microscopy. Next, AFM was applied to investigate the detailed cellular behaviors during macrophage phagocytosis under the guidance of fluorescence recognition. AFM imaging revealed the distinct features in cellular ultramicrostructures for the different steps of macrophage phagocytosis. AFM cell mechanical property measurements indicated that the binding of cancer cells to macrophages could make macrophages become stiffer. The experimental results provide novel insights in understanding the Fc-receptor-mediated macrophage phagocytosis.

“…In recent years, researchers have used sphere tips to quantify the mechanical properties of the whole living cells [16,35,38,39]. Compared with conical tips, sphere tips have larger contact areas and thus smaller applied pressures, causing that cellular Young's modulus measured with sphere tips is less than that with conical tips [40]. Despite this difference, the studies by Rico et al [41] have showed that the change trend of cellular Young's modulus measured using sphere tips was consistent with that using conical tips.…”

Section: Discussionmentioning

confidence: 99%

Effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells investigated by atomic force microscopy

et al. 2015

Sci. China Life Sci.

Cell mechanics plays an important role in cellular physiological activities. Recent studies have shown that cellular mechanical properties are novel biomarkers for indicating the cell states. In this article, temperature-controllable atomic force microscopy (AFM) was applied to quantitatively investigate the effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells. First, AFM indenting experiments were performed on six types of human cells to investigate the changes of cellular Young's modulus at different temperatures and the results showed that the mechanical responses to the changes of temperature were variable for different types of cancer cells. Second, AFM imaging experiments were performed to observe the morphological changes in living cells at different temperatures and the results showed the significant changes of cell morphology caused by the alterations of temperature. Finally, by co-culturing human cancer cells with human immune cells, the mechanical and morphological changes in cancer cells were investigated. The results showed that the co-culture of cancer cells and immune cells could cause the distinct mechanical changes in cancer cells, but no significant morphological differences were observed. The experimental results improved our understanding of the effects of temperature and cellular interactions on the mechanics and morphology of cancer cells. atomic force microscopy, mechanics, cancer cell, temperature, cellular interactions Citation:Li M, Liu LQ, Xi N, Wang YC, Xiao XB, Zhang WJ. Effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells investigated by atomic force microscopy. Sci China Life Sci, 2015Sci, , 58: 889 -901, doi: 10.1007 The past decade has seen substantial growth in the studies on how changes in the biomechanical and biophysical properties of cells influence, and are influenced by, the onset and progression of many human diseases . Recently, a comprehensive study on human breast tissues has shown that cell mechanics is an effective biomarker that can identify the different stages (normal tissue, benign lesion and invasive cancer) in the process of cancer development [10]. Thus, it is expected that the studies of cell mechanics will have a significant impact on cancer diagnosis and treatment.