scholarly journals Nanorheology of living cells measured by AFM-based force–distance curves

Nanoscale ◽  
2020 ◽  
Vol 12 (16) ◽  
pp. 9133-9143 ◽  
Author(s):  
Pablo D. Garcia ◽  
Carlos R. Guerrero ◽  
Ricardo Garcia

Method to measure the viscoelastic properties of a living cell by AFM-based force–distance curves.

RSC Advances ◽  
2021 ◽  
Vol 11 (31) ◽  
pp. 18898-18914
Author(s):  
Katsuhiko Ariga ◽  
Rawil Fakhrullin

We can introduce functional structures with various components on a living cell as if architectures were constructed on material surfaces.


2008 ◽  
Vol 48 (supplement) ◽  
pp. S175
Author(s):  
Shinichiro Hiratsuka ◽  
Yusuke Mizutani ◽  
Masahiro Tsuchiya ◽  
Koichi Kawahara ◽  
Hiroshi Tokumoto ◽  
...  

2010 ◽  
Vol 5 (1) ◽  
pp. 90-96
Author(s):  
Aleksandr V. Kopylov ◽  
Viktor Ya. Prinz

The possibility of application of the novel class of tubular needles for piercing cells and injecting biological material inside the cell is considered. Stability calculations of tubular (multiwall) needles were made. Calculations were made for the needles with walls formed from hybrid graphene-semiconductor or graphene structures and spires shaped as trapeziform open cylindrical shells. The possibility of mass fabrication of such needles and chips for AFM significantly broadens the range of available operations on the surface and inside the living cell and opens prospects of effective high-precision manipulations with individual cells.


Author(s):  
Daniel M. Dubois ◽  
Stig C. Holmberg

A survey of the Varela automata of autopoiesis is presented. The computation of the Varela program, with initial conditions given by a living cell, is not able to self-maintain the membrane of the living cell. In this chapter, the concept of anticipatory artificial autopoiesis (AAA) is introduced. In this chapter, the authors present a new algorithm of the anticipatory artificial autopoiesis, which extend the Varela automata. The main enhancement consists in defining an asymmetric membrane of the artificial lining cell. The simulations show the anticipatory generation of artificial living cells starting with any initial conditions. The new concept of anticipatory artificial autopoiesis is related to artificial life (Alife) and artificial intelligence (AI). This is a breakthrough in the computational foundation of autopoiesis.


2019 ◽  
Vol 32 (5) ◽  
pp. 599-610 ◽  
Author(s):  
Yang Bu ◽  
Long Li ◽  
Chendong Yang ◽  
Rui Li ◽  
Jizeng Wang

Recent work on the osmotic pressure of the hen’s egg has introduced a sense of uncertainty as to the value of the many comparisons which have been made between osmotic pressures of the blood, body fluids, and surrounding media. The uncertainty pertains not to theory but to a simple matter of fact and, as this involves that most fundamental datum for biological theory—viz., the state of the water in the living cell—there is urgent need to have it cleared up. The fact in dispute is the freezing point of the yolk and white of the bird’s egg. Atkins in 1909 by measurements, obviously made with the greatest care, found “no difference between the freezing point of white and yolk of the same egg and a mixture of white and yolk gave the same depression.” Atkins (1909) used the ordinary Beckmann technique and so, too, did Straub (1929) twenty years later, but with a surprisingly different result for he found a constant difference between white and yolk of the hen’s egg amounting on the average to —0·15° C. A. V. Hill (1930) confirmed Straub’s (1929) finding by a different method. He compared the fall in temperature caused by evaporation with that of water and from the difference calculated the osmotic pressure. Howard (1932) using the Beckmann method again found no difference in the freezing point of white and yolk. In these measurements the yolk was puddled by stirring so that at sometime or another the structure was broken down. Yolk is not only a chemical complex but it is alive, gross mechanical disturbance might, therefore, have the effect it usually has on living cells and cause chemical breakdown with consequent fall of the freezing point. Hale’s experiments were designed to explore this possibility by observing directly the freezing point of intact yolk and white.


1997 ◽  
Vol 3 (S2) ◽  
pp. 133-134 ◽  
Author(s):  
Ammasi Periasamy ◽  
Richard N. Day

The pituitary specific transcription factor Pit-1 is required for transcriptional activity of the prolactin (PRL) gene. The Pit-1 protein is a member of the POU homeodomain transcription factors that is expressed in several different anterior pituitary cell types, where it functions as an important determinant of pituitary-specific gene expression. The Pit-1 protein generally interacts with DNA elements in the PRL gene promoter as a dimer, and has been demonstrated to associate with other transcription factors. The objective of our research is to define the critical molecular events involved in transcriptional regulation of the PRL gene in living cells. Methods that allow monitoring of the intimate interactions between protein partners in living cells provide an unparalleled perspective on these biological processes. Using the jellyfish green fluorescent protein (GFP) as a tag, we applied the fluorescence resonance energy transfer (FRET) technique to visualize where and when the Pit-1 protein interacts in the living cell. FRET is a quantum mechanical effect that occurs between donor (D) and acceptor (A) fluorophores provided: (i) the emission energy of D is coincident with the energy required to excite A, and (ii) the distance that separating the two fluorophores is 10-100 Å. Mutant forms of GFP that fluoresce either green or blue (BFP) have excitation and emission spectra that are suitable for FRET imaging.


Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 495
Author(s):  
Takayuki Shibata ◽  
Hiromi Furukawa ◽  
Yasuharu Ito ◽  
Masahiro Nagahama ◽  
Terutake Hayashi ◽  
...  

Atomic force microscopy (AFM) is an effective platform for in vitro manipulation and analysis of living cells in medical and biological sciences. To introduce additional new features and functionalities into a conventional AFM system, we investigated the photocatalytic nanofabrication and intracellular Raman imaging of living cells by employing functionalized AFM probes. Herein, we investigated the effect of indentation speed on the cell membrane perforation of living HeLa cells based on highly localized photochemical oxidation with a catalytic titanium dioxide (TiO2)-functionalized AFM probe. On the basis of force–distance curves obtained during the indentation process, the probability of cell membrane perforation, penetration force, and cell viability was determined quantitatively. Moreover, we explored the possibility of intracellular tip-enhanced Raman spectroscopy (TERS) imaging of molecular dynamics in living cells via an AFM probe functionalized with silver nanoparticles in a homemade Raman system integrated with an inverted microscope. We successfully demonstrated that the intracellular TERS imaging has the potential to visualize distinctly different features in Raman spectra between the nucleus and the cytoplasm of a single living cell and to analyze the dynamic behavior of biomolecules inside a living cell.


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