Giant cell formation in cells exposed to 740 nm and 760 nm optical traps

Liu, Hong; Vu, Ky Trong; Trang, Tina Ching; Shin, David S.; Lee, Yider Eddie; Nguyen, Ducc Chi; Tromberg, Bruce J.; Berns, Michael W.

doi:10.1002/(sici)1096-9101(1997)21:2<159::aid-lsm7>3.3.co;2-l

Cited by 5 publications

(6 citation statements)

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“…Stress response occurred most frequently at 760 nm. A high frequency of stress induction in C. elegans at 760 nm is in agreement with results from other studies showing increased laserinduced damages in other biological systems at this particular wavelength (Vorobjev et al, 1993;König et al, 1997;Liang et al, 1997).…”

Section: Consequences For Users Of Optical Tweezerssupporting

confidence: 91%

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Stress Response in Caenorhabditis elegans Caused by Optical Tweezers: Wavelength, Power, and Time Dependence

Leitz

Fällman

Tuck

et al. 2002

Biophysical Journal

117

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Optical tweezers have emerged as a powerful technique for micromanipulation of living cells. Although the technique often has been claimed to be nonintrusive, evidence has appeared that this is not always the case. This work presents evidence that near-infrared continuous-wave laser light from optical tweezers can produce stress in Caenorhabditis elegans. A transgenic strain of C. elegans, carrying an integrated heat-shock-responsive reporter gene, has been exposed to laser light under a variety of illumination conditions. It was found that gene expression was most often induced by light of 760 nm, and least by 810 nm. The stress response increased with laser power and irradiation time. At 810 nm, significant gene expression could be observed at 360 mW of illumination, which is more than one order of magnitude above that normally used in optical tweezers. In the 700-760-nm range, the results show that the stress response is caused by photochemical processes, whereas at 810 nm, it mainly has a photothermal origin. These results give further evidence that the 700-760-nm wavelength region is unsuitable for optical tweezers and suggest that work at 810 nm at normal laser powers does not cause stress at the cellular level.

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Section: Consequences For Users Of Optical Tweezerssupporting

confidence: 91%

“…age (Vorobjev et al, 1993;König et al, 1997;Liang et al, 1997). They also support the previous finding that optical tweezers employing light in the 760-nm region can cause damage to cells and that this damage results from photochemical effects (Neumann et al, 1999).…”

Section: Photothermal Versus Photochemical Effectssupporting

confidence: 85%

Stress Response in Caenorhabditis elegans Caused by Optical Tweezers: Wavelength, Power, and Time Dependence

Leitz

Fällman

Tuck

et al. 2002

Biophysical Journal

117

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“…Our results suggest a stimulatory effect of PDT with a laser at 100 mW and Phthalomethyl D on the formation of giant cells. These results disagree with those of Liang et al, [40] who found that preselected single Chinese hamster ovary (CHO) cells exposed to 740 and 760 nm laser microbeam generated by a titanium-sapphire laser at 86 and 174 mW and different time exposures had poor ability to divide and to form giant cells. However, they suggest a relationship between increased giant cell formation and exposure time to PDT and higher power density.…”

Section: Discussioncontrasting

confidence: 94%

Photodynamic Therapy with Phthalomethyl D: Perspectives against SARS-CoV-2

Pinto¹,

Silva²,

Sampaio³

et al. 2020

JBM

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Background: Photodynamic therapy (PDT) is the generation of cytotoxic agents through the dynamic interaction between a photosensitizer excited by light at a specific wavelength. When associated with phthalocyanines, they are efficient in incorporating target cells and exhibiting high rates of triplet generation. This study aimed to characterize PDT associated with the phototherapeutic agent Phthalomethyl D, developed by the authors, in the process of repair, healing and immune improvement for possible application against SARS-CoV-2. Methods: Sixty-nine mice were used, divided into 2 groups: GI, treated with ILIB laser, without a phototherapeutic agent, and subjected to surgery for viral induction; GII, same as GI plus association of Phthalomethyl D. They were divided into subgroups and reevaluated at 7, 14, and 21 days, and then divided into 3 subgroups of 6 animals each, subjected to treatment at 24 h, 48 h, 72 h, 5 and 7 days. Results: Both groups had a high rate of partial incision closure and acute inflammatory control. Microscopically, there was a greater amount of amorphous fundamental substance, fibrocytes, fibroblasts, and giant cells and reduction in the number of keratinocytes, in the amount of keratin, and epidermal thickness in GII than in GI. Conclusions: PDT with Phthalomethyl D stimulates the processes of healing/repair and immunomodulation during viral infection, initially favoring the inflammatory response and, after

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“…A few of the first studies using femtosecond lasers observed the decreased cloning efficiency of cells restrained by optical traps [37][38][39] or imaged with two-photon microscopes [40]. Some cells become giant cells with multiple nuclei [41], and others undergo apoptosis because of laser-generated reactive oxygen species [42]. However, proteins involved in recognizing and repairing DNA are also present after surgery to mitigate damage [43].…”

Section: Experimental Backgroundmentioning

confidence: 99%

Surgical applications of femtosecond lasers

Chung¹,

Mazur

2009

Journal of Biophotonics

231

136

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Femtosecond laser ablation permits non‐invasive surgeries in the bulk of a sample with submicrometer resolution. We briefly review the history of optical surgery techniques and the experimental background of femtosecond laser ablation. Next, we present several clinical applications, including dental surgery and eye surgery. We then summarize research applications, encompassing cell and tissue studies, research on C. elegans, and studies in zebrafish. We conclude by discussing future trends of femtosecond laser systems and some possible application directions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Giant cell formation in cells exposed to 740 nm and 760 nm optical traps

Cited by 5 publications

References 0 publications

Stress Response in Caenorhabditis elegans Caused by Optical Tweezers: Wavelength, Power, and Time Dependence

Stress Response in Caenorhabditis elegans Caused by Optical Tweezers: Wavelength, Power, and Time Dependence

Photodynamic Therapy with Phthalomethyl D: Perspectives against SARS-CoV-2

Surgical applications of femtosecond lasers

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