Laser therapy cell proliferation, human cells, stem cells

Photomedicine and Laser Surgery Volume 30, Number 3, 2012

Isxıl Saygun, D.D.S., Ph.D.,1 Nejat Nizam, D.D.S., Ph.D.,2 Ali Ug� ur Ural, M.D.,Ph.D.,3 Muhittin Abdu¨ lkadir Serdar, M.D.,Ph.D.,4 Ferit Avcu, M.D., Ph.D.,3 and Tolga Fikret To¨zu¨m, D.D.S., Ph.D.5

Objectives: It was the aim of the present study to evaluate whether the laser irradiation of osteoblasts could enhance the release of growth factors including basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), and receptor of IGF-I (IGFBP3). Background data: Low-level laser therapy (LLLT) has been shown to have biostimulatory effects on various cell types by enhancing production of some cytokines and growth factors.

Methods: Human mesenchymal stem cells (MSCs) were seeded in osteogenic medium and differentiated into osteoblasts. Three groups were formed: in the first group (single dose group), osteoblasts were irradiated with laser (685 nm, 25mW, 14.3 mW/cm2, 140 sec, 2 J/cm2) for one time; and in the second group, energy at the same dose was applied for 2 consecutive days (double dose group). The third group was not irradiated with laser and served as the control group. Proliferation, viability, bFGF, IGF-I, and IGFBP3 levels were compared between groups.

Results: Both of the irradiated groups revealed higher proliferation, viability, bFGF, IGF-I, and IGFBP3 expressions than did the nonirradiated control group. There was increase in bFGF and IGF-I expressions and decrease in IGFBP3 in the double dose group compared to single dose group.

Conclusions: The results of the present study indicate that LLLT increases the proliferation of osteoblast cells and stimulates the release of bFGF, IGF-I, and IGFBP3 from these cells. The biostimulatory effect of LLLT may be related to the enhanced production of the growth factors.

Photomedicine and laser surgery; VOL: 22 (6); p. 523-6 /200412/
Dipartimento di Biologia, UniversitÃ&xnbsp; degli Studi di Padova, Padova, Italy.

Objective: The aim of this study was to investigate the effects of different wavelengths and doses of laser radiation on in vitro cell proliferation. We evaluated the biological effects of low-level laser therapy (LLLT) on two human cancer cell lines: HeLa (epithelial adenocarcinoma) and TK6 (lymphoblast). Our attention was focused on the combination of the two laser emissions as it could have a synergic effect greater than the single emission applied separately.

Background Data: The effects of LLLT on human cells are still poorly understood and unexplained. Several cell types were found non responsive to laser bio stimulation; in other cases, only a partial activation was observed.

Methods: A laser device was used for cell irradiation with a continuous wave diode (lambda = 808 nm), a pulsed wave diode (lambda = 905 nm), and a combined wave diodes (lambda = 808 nm + 905 nm), in the dose range of 1-60 J/cm(2).

Results: The effect of the combined low-level 808-905-nm diode laser irradiation were slightly superior to those achieved with either laser alone in HeLa cells. TK6 cellular proliferation was not found to be significantly affected by any of the energy levels and varying exposure doses investigated.

Conclusions: Our results are a confirmation of previous observations carried out on human cells, where only the proliferation of slowly growing cell populations appeared to be stimulated by laser light.

Brazilian dental journal; VOL: 13 (2); p. 109-12 /2002/
Faculty of Dentistry, Federal University of Bahia, Salvador, BA, Brazil. This email address is being protected from spambots. You need JavaScript enabled to view it.

Low level laser therapy (LLLT) has been used successfully in biomedicine and some of the results are thought to be related to cell proliferation. The effects of LLLT on cell proliferation is debatable because studies have found both an increase and a decrease in proliferation of cell cultures. Cell culture is an excellent method to assess both effects and dose of treatment.

The aim of this study was to assess the effect of 635nm and 670 nm laser irradiation of H.Ep.2 cells in vitro using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). The cells were obtained from squamous cell carcinoma (SCC) of the larynx and were routinely processed from defrost to the experimental condition. Twenty-four hours after transplantation the cells were irradiated with doses ranging from 0.04 to 0.48J/cm2 for seven consecutive days (5 mW diode lasers: 635nm or 670 nm, beam cross-section approximately 1 mm) at local light doses between 0.04 and 0.48 J/cm2.

The results showed that 635nm laser light did not significantly stimulate the proliferation of H.Ep.2 cells at doses of 0.04 J/cm2 to 0.48 J/cm2, However, 670nm laser irradiation led to an increased cell proliferation when compared to both control and 635nm irradiated cells.

The best cell proliferation was found with 670nm laser irradiated cultures exposed to doses of doses of 0.04 to 0.48 J/cm2. We conclude that both dose and wavelength are factors that may affect cell proliferation of H.Ep.2 cells.

Photomedicine and Laser Surgery
Volume 34, Number 11, 2016

Low-Level Laser Therapy to the Bone Marrow Reduces Scarring and Improves Heart Function Post-Acute Myocardial Infarction in the Pig
Alex Blatt, MD,1,2* Gabby A. Elbaz-Greener, MD,1,2* Hana Tuby, PhD,3 Lidya Maltz, MSc,3. Yariv Siman-Tov, DVM,4 Gad Ben-Aharon, BSc,4 Laurian Copel, MD,5 Itzhak Eisenberg, DVM,6. Shai Efrati, MD,4 Michael Jonas, MD,7 Zvi Vered, MD,1,2 Sigal Tal, MD,5
Orly Goitein, MD,8 and Uri Oron, PhD3
Abstract
Objective: Cell therapy for myocardial repair is one of the most intensely investigated strategies for treating acute myocardial infarction (MI). The aim of the present study was to determine whether low-level laser therapy (LLLT) application to stem cells in the bone marrow (BM) could affect the infarcted porcine heart and reduce scarring following MI. Methods: MI was induced in farm pigs by percutaneous balloon inflation in the left coronary artery for 90 min. Laser was applied to the tibia and iliac bones 30 min, and 2 and 7 days post-induction of MI. Pigs were euthanized 90 days post-MI. The extent of scarring was analyzed by histology and MRI, and
heart function was analyzed by echocardiography. Results: The number of c-kit+ cells (stem cells) in the circulating blood of the laser-treated (LT) pigs was 2.62- and 2.4-fold higher than in the non-laser-treated (NLT) pigs 24 and 48 h post-MI, respectively. The infarct size [% of scar tissue out of the left ventricle (LV) volume as measured from histology] in the LT pigs was 3.2 – 0.82%, significantly lower, 68% (p < 0.05), than that (16.6 – 3.7%) in the NLT pigs. The mean density of small blood vessels in the infarcted area was significantly higher [6.5-fold (p < 0.025)], in the LT pigs than in the NLT ones. Echocardiography (ECHO) analysis for heart
function revealed the left ventricular ejection fraction in the LT pigs to be significantly higher than in the NLT ones. Conclusions: LLLT application to BM in the porcine model for MI caused a significant reduction in scarring, enhanced angiogenesis and functional improvement both in the acute and long term phase post-MI.

Photomedicine and Laser Surgery
Volume 34, Number 11, 2016

Effect of Photobiomodulation on Mesenchymal Stem Cells
Reza Fekrazad, DDS, MS, FSLD,1 Sohrab Asefi, DDS, MS,2 Mahdi Allahdadi, DDS,3, and Katayoun A.M. Kalhori, DDS, MS, MSc4
Abstract
Objective: The purpose of this studywas to review available literature about the effect of photobiomodulation (PBM) on mesenchymal stem cells (MSCs). Background data: The effects of coherent and noncoherent light sources such as low-level lasers and light-emitting diodes (LEDs) on cells and tissues, known as PBM, form the basis of photomedicine. This treatment technique effects cell function, proliferation, and migration, and plays an important role in tissue regeneration. Stem cells have been found to be helpful elements in tissue regeneration, and the combination of stem cell therapy and laser therapy appears to positively affect treatment results. Materials and methods: An electronic search in PubMed was conducted of publications from the previous 12 years. English language articles related to the subject were found using selected key words. The full texts of potentially suitable articles were assessed according to inclusion and exclusion criteria. Results: After evaluation, 30 articles were deemed relevant according to the inclusion criteria. The energy density of the laser was 0.7–9 J/cm2. The power used for visible lightwas 30–110mWand that used for infrared light was 50–800mW.Nearly all studies showed that low level laser therapy had a positive effect on cell proliferation. Similar outcomes were found for LED; however, some studies suggest that the laser alone is not effective, and should be used as an adjunct tool. Conclusions: PBM has positive effects on MSCs. This review concluded that doses of 0.7–4 J/cm2 and wavelengths of 600–700 nm are appropriate for light therapy. The results were dependent upon different parameters; therefore, optimization of parameters used in light therapy to obtain favorable results is required to provide more accurate comparison.