&lt;title&gt;Photothermal microscopy for cell imaging and diagnostics&lt;/title&gt;

Lapotko, Dmitri O.; Kuchinsky, Georgy

doi:10.1117/12.205988

Cited by 13 publications

(10 citation statements)

References 1 publication

(2 reference statements)

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“…Such load has thermal and mechanical origin due to light absorption by natural cell chromophores. With optical noninvasive registration of cell response we come to the idea of photothermal cytometry ' S. 9 -RBC in functional terms has limited ability to restore its structure, to maintain energy balance and ion transport through the membrane. Besides RBC does not produce proteins neither incorporates DNA and therefore is considered to be rather stable and predictable cell.…”

Section: Introductionmentioning

confidence: 99%

Human cell viability to laser pulse and ion transport processes

Lapotko

Romanovskaya

2000

SPIE Proceedings

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We have studied experimentally the problem of cell viability during laser-tissue interaction: how the cell viability can be regulated under certain laser regime. Many modern laser therapeutic techniques assume that cells should survive laser therapy or even to become activated (laser stimulation of immune system). An influence of ion balance was studied for human Red Blood Cells (RBC) during in vitro measurements of single RBC viability after laser pulse. Single cell viability was measured optically with Laser Viability Test which is based upon interpretation of cell photothermal response to pump pulse (532 mu, 10 ns, 10 -50 pJ at 12 jim diameter). According to our experiments laser-induced cell damage occurs at different laser energy levels within one cell population (heterogeneity of cell viability) and besides is donor-dependent. The latter result means that laser therapeutic dose should be adjusted individually. For solutions of the ions Nat. K. CC and Mg we have found strong dependence of cell viability upon the process of ion transport through the cell membrane which was regulated by variation of concentration and composition of above mentioned ions. An increase of Na or concentration causes a decrease of RBC laser viability.

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Section: Introductionmentioning

confidence: 99%

Human cell viability to laser pulse and ion transport processes

Lapotko

Romanovskaya

2000

SPIE Proceedings

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“…[47][48][49][50][51][52][53][54][55][56][57] PTI is based on irradiating cells with a focused short-pulse pump laser and recording the temperature-dependent variations of the refractive index with phase-contrast imaging of a second collinear laser pulse. It was shown that PT response from different cells is sensitive to different environmental impact including temperature, chemicals, and drugs.…”

Section: Introductionmentioning

confidence: 99%

Photothermal images of live cells in presence of drug

2002

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A new method for the study of drug-cell interaction is suggested. It is based on optical monitoring of cell response to drug impact. To detect this response, a high sensitive photothermal imaging technique has been developed. This technique is based on irradiation of the cells with a focused short pulse double-frequency pump laser (532 nm, 8 ns) and monitoring the laser-induced local thermal effects. This is realized with a second collinear dye laser pulse (630 nm, 6 ns) that probes the heated cell absorbing zones. The temperature-dependent variations of the refractive index in the absorbing zones in cross section of probe beam are recorded with phase-contrast technique. The photothermal (PT) image represents a two-dimensional depth-integrated temperature distribution in the irradiated volume and correlates with the conventional optical absorption images. It was experimentally shown that the introduction of NaN(3) or anti-tumor drug in the cell suspension led to a change in the structure of PT images of human lymphocytes and human lympholeukemia cells, respectively. It was hypothesized that the observed effects could be associated with the change of redox state of respiratory chain component.

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“…However to date a little progress has been made in biological applications, and no results have been reported for imaging of single live cells. The PTI is new modification of calorimetric technique and is based on combination of laser PT dual beam time-resolved technique and phase-contrast microscopy [28][29][30][31][32][33][34][35]. This paper is focused on discussion of PTI features for single live cells studies through visualization of laser-induced local thermal effects.…”

Section: Introductionmentioning

confidence: 99%