Photomedicine and Laser Surgery Volume 34, Number 11, 2016 ª Mary Ann Liebert, Inc. Pp. 516–524 DOI: 10.1089/pho.2015.3988
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
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 5.2 – 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. Keywords: angiogenesis, cardioprotection, low-level lasers, myocardial infarction, porcine model
Photomedicine and Laser Surgery Volume 34, Number 11, 2016 ª Mary Ann Liebert, Inc. Pp. 533–542 DOI: 10.1089/pho.2015.4029
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
Objective: The purpose of this study was 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 light was 30–110 mW and that used for infrared light was 50–800 mW. Nearly all studies showed that lowlevel 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.
Keywords: light-emitting diode (LED) lasers, low-level laser therapy, photobiomodulation, photochemotherapy, semiconductor
Photomedicine and Laser Surgery Volume 34, Number 12, 2016 ª Mary Ann Liebert, Inc. Pp. 627–630 DOI: 10.1089/pho.2015.4072
Low-Level Laser Therapy to the Bone Marrow Ameliorates Neurodegenerative Disease Progression in a Mouse Model of Alzheimer’s Disease: A Minireview
Amir Oron, MD,1 and Uri Oron, PhD2
Objective: This communication reviews the ability of low-level laser therapy (LLLT) to stimulate mesenchymal stem cells (MSCs) in autologous bone marrow (BM) to enhance the capacity of MSCs to infiltrate the brain, clear b-amyloid, and improve cognition. Background: We recently reported that LLLT applied to the BM enhanced the proliferation of MSCs and their mobilization toward the ischemic heart region, suggesting a possible application of this approach in regenerative medicine and neurodegenerative diseases. It was also shown that circulating monocytes can infiltrate the brain and reduce brain amyloid load in an Alzheimer’s disease (AD) mouse model.
Methods and Results: MSCs from wild-type mice stimulated with LLLT demonstrated an increased ability to maturate toward a monocyte lineage and to increase phagocytosis of soluble Ab in vitro. Furthermore, weekly LLLT for 2 months to the BM, starting at 4 months of age (progressive stage of the disease in these 5XFAD transgenic male mice), improved memory and spatial learning, compared to a sham-treated AD mouse model. Histology revealed a significant reduction in Ab brain burden in the laser-treated mice compared to the nonlasertreated ones.
Conclusions: The application of LLLT to the BM is suggested as a therapeutic approach in progressive stages of AD, and its potential role in mediating MSC therapy in brain amyloidogenic disease is implied.
Keywords: amyloid beta (Ab), bone marrow (BM), mesenchymal stem cells (MSC), Alzheimer’s disease (AD), low-level laser therapy (LLLT), exosomes