Development of Quantum Dot Mediated Cell Image Deformetry for Microscale Tissue Deformation Measurement

Author(s):  
Jun K. Jung ◽  
Ka Yaw Teo ◽  
J. Craig Dutton ◽  
Bumsoo Han

Since biological tissues are composed of cells, extracellular matrix, and interstitial fluid, freezing of biological tissues induces complex cell-fluid-matrix interaction. Quantitative understanding of this cell-fluid-matrix interaction is crucial to the design and optimization of a wide variety of cryomedicine applications. However, quantitative measurement of the interaction is extremely challenging due to the lack of reliable non-invasive measurement techniques during freezing and thawing. In the present study, a new measurement technique was developed to dynamically measure microscale tissue deformation during freezing/thawing and its feasibility was demonstrated. In this method, which is named “Cell Image Deformetry” (CID), engineered tissues with pre-labeled cells with quantum dots are imaged under a fluorescence microscope. Then, the tissue deformation is evaluated by cross-correlating cell locations between sequential microscopic images with known time intervals based on the particle image velocimetry (PIV) data processing technique.

Author(s):  
Junkyu Jung ◽  
Ka Yaw Teo ◽  
J. Craig Dutton ◽  
Bumsoo Han

Freezing of biological tissues occurs in cryomedicine applications such as cryosurgery and cryopreservation. Although cellular level biophysics during freezing and thawing (F/T) has been extensively studied, tissue level biophysics is not fully understood yet. Especially, the effects of F/T on the functionalities of tissue are not well understood so that the outcomes of cryomedicine applications are highly tissue-type dependent [1]. Although many of the functionalities are associated with the extracellular matrix (ECM), the effect of F/T on ECM microstructure has been overlooked. Quantitative understanding on the post-thaw ECM structure is rarely available, but it is essential to design and improve cryopresevation and cryotherapy protocols for a wide variety of native and engineered tissues.


2018 ◽  
Vol 9 (1) ◽  
pp. 142-158 ◽  
Author(s):  
M. Amini ◽  
J. Hisdal ◽  
H. Kalvøy

Abstract Rapid development in the field of tissue engineering necessitates implementation of monitoring methods for evaluation of the viability and characteristics of the cell cultures in a real-time, non-invasive and non-destructive manner. Current monitoring techniques are mainly histological and require labeling and involve destructive tests to characterize cell cultures. Bioimpedance measurement technique which benefits from measurement of electrical properties of the biological tissues, offers a non-invasive, label-free and real-time solution for monitoring tissue engineered constructs. This review outlines the fundamentals of bioimpedance, as well as electrical properties of the biological tissues, different types of cell culture constructs and possible electrode configuration set ups for performing bioimpedance measurements on these cell cultures. In addition, various bioimpedance measurement techniques and their applications in the field of tissue engineering are discussed.


2020 ◽  
Vol 10 (23) ◽  
pp. 8563
Author(s):  
Sangmo Koo

Two-photon polymerization (TPP) based on the femtosecond laser (fs laser) direct writing technique in the realization of high-resolution three-dimensional (3D) shapes is spotlighted as a unique and promising processing technique. It is also interesting that TPP can be applied to various applications in not only optics, chemistry, physics, biomedical engineering, and microfluidics but also micro-robotics systems. Effort has been made to design innovative microscale actuators, and research on how to remotely manipulate actuators is also constantly being conducted. Various manipulation methods have been devised including the magnetic, optical, and acoustic control of microscale actuators, demonstrating the great potential for non-contact and non-invasive control. However, research related to the precise control of microscale actuators is still in the early stages, and in-depth research is needed for the efficient control and diversification of a range of applications. In the future, the combination of the fs laser-based fabrication technique for the precise fabrication of microscale actuators/robots and their manipulation can be established as a next-generation processing method by presenting the possibility of applications to various areas.


2020 ◽  
Author(s):  
Sirimuvva Tadepalli ◽  
Sisi Cao ◽  
Debajit Saha ◽  
Keng-Ku Liu ◽  
Alex Chen ◽  
...  

Developing insect cyborgs by integrating external components (optical, electrical or mechanical) with biological counterparts has a potential to offer elegant solutions for complex engineering problems.1 A key limiting step in the development of such biorobots arises at the nano-bio interface, i.e. between the organism and the nano implant that offers remote controllability.1,2 Often, invasive procedures are necessary that tend to severely compromise the navigation capabilities as well as the longevity of such biorobots. Therefore, we sought to develop a non-invasive solution using plasmonic nanostructures that can be photoexcited to generate heat with spatial and temporal control. We designed a ‘nanotattoo’ using silk that can interface the plasmonic nanostructures with a biological tissue. Our results reveal that both structural and functional integrity of the biological tissues such as insect antenna, compound eyes and wings were preserved after the attachment of the nanotattoo. Finally, we demonstrate that insects with the plasmonic nanotattoos can be remote controlled using light and integrated with functional recognition elements to detect the chemical environment in the region of interest. In sum, we believe that the proposed technology will play a crucial role in the emerging fields of biorobotics and other nano-bio applications.


Author(s):  
Patrick Magee ◽  
Mark Tooley

Blood pressure measurement occurs either non-invasively or invasively, and usually refers to systemic arterial pressure measurement, but can also refer to systemic venous or pulmonary arterial pressure measurement. In 1733 the Reverend Stephen Hales was the first person to measure the blood pressure in vivo in unanaesthetised horses by direct cannulation of the carotid and femoral arteries. In doing so he observed the pulsatile nature of flow in the circulation. In 1828 Poiseuille developed the mercury manometer, and used it to measure blood pressure in a dog. The mercury manometer has, of course, become the standard technique against which other techniques are compared. The earliest numerical information on blood pressure measurement came from direct rather than indirect measurement in 1856 by Faivre, using Poiseuille’s device. However, in the last part of the nineteenth century, non-invasive measurement techniques were developed. In 1903, Codman and Cushing introduced the concept of routine intraoperative blood pressure measurement, which at the time was a revolutionary concept. Nowadays it is a fundamental part of minimal monitoring criteria. There are several techniques of non-invasive BP (NIBP) measurement, all of which function by occluding the pulse in a limb with a proximal cuff, then detecting its onset again distally, on lowering the cuff pressure. Detection methods include palpation, auscultation, plethysmography, oscillotonometry and oscillometry. Accuracy of all non-invasive techniques depends on cuff size in relation to the limb concerned, and over which artery the cuff is placed. Such techniques of NIBP measurement are necessarily intermittent. Much discussion has taken place on the accuracy of these devices, and the accuracy of diastolic pressure measurements needs improving, and there are ideas proposed for new non-invasive devices [Tooley and Magee 2009]. In the absence of a stethoscope, this technique is simple and reliable. After inflating the cuff on the upper arm to a pressure of above that of systolic, the cuff is then deflated while palpating the brachial artery and the systolic pressure is measured with a mercury column at first detection of the pulse. A study by van Bergen [1954] showed that BP can be underestimated by this method by up to 25% at 120 mmHg.


The Analyst ◽  
2019 ◽  
Vol 144 (8) ◽  
pp. 2618-2627 ◽  
Author(s):  
Saeideh Ostovar pour ◽  
Stephanie M. Fowler ◽  
David L. Hopkins ◽  
Peter J. Torley ◽  
Harsharn Gill ◽  
...  

Spatially off-set Raman spectroscopy (SORS) offers non-invasive chemical characterisation of the sub-surface of various biological tissues as it permits the assessment of diffusely scattering samples at depths of several orders of magnitude deeper than conventional Raman spectroscopy.


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