Low energy laser bio-stimulation of bone marrow stem cells for the treatment of myocardial infarction
rLLLT is a remote (non-invasive) Low Level Laser Therapy to the tibia of AMI patients. rLLLT mobilizes autologous bone marrow stem cells into the blood stream, where they home to the ischemic organ, induce paracrine secretion of growth factors, enhancing cytoprotection, cardiogenesis and angiogenesis. Collectively, the beneficial effects of rLLLT are a result of several mechanisms acting in concert leading to a significant reduction in scarring and improved cardiac function. These beneficial effects can be achieved with a single rLLLT up to 4 hours post MI. Improved effects can be achieved with multiple (3-4) rLLLT starting 30 minutes post MI.
We have also demonstrated improvement of kidney function and histopathology by rLLLT delivered in the same manner as for the heart, demonstrating also its efficacy in other ischemic organs
· “Soft” laser irradiation at the infrared range.
· Power is up to 0.1W (compared to 1W in surgical laser)
· Application does not cause heat
1. Mechanism of Action
Following rLLLT, photons are absorbed by cytochrome c-oxidase and a cascade of processes commence, leading to upregulation of ATP production, expression of heat shock proteins, VEGF and iNOS enhancement, and cell proliferation. rLLLT induces enhanced proliferation of stem cells in the BM and consequent elevation of c-kit+ cells in the blood stream. The c-kit+ cells macrophages home specifically at the ischemic zone in the heart
2. In vivo studies
Porcine Model – Experimental Protocol
- MI was induced by occlusion between 2nd & 3rd diagonal of LAD for 90 min by balloon catheter and then reperfusion.
- Random selection for control (no laser application) or rLLLT application for 100 sec to tibia and illium for 30 min after balloon deflation.
- rLLLT was applied again also on days 2 & 7 post MI.
- Blood samples were collected for Troponin-I, CPK, antioxidants and FACS analysis .
- Swine were subjected to ECHO and MRI analysis
- rLLLT was applied also on days 2 & 7 post MI.
- Animals were sacrifice 90 days post MI (Cardiac MRI performed to some pigs prior to sacrifice) hearts were subjected to Histopathology
The infarct size (% of scar tissue out of the LV volume as measured from histology) in rLLLT treated pigs was 3.2±0.82, which was 68% significantly (p<0.05) lower than the infarct size (16.6±3.7%) in the control pigs. At 24 hrs post-MI the level of Toponin-I in the blood of the rLLLT pigs was significantly (p<0.002) 44% lower in the laser-treated pigs relative to the control. The mean density of small blood vessels in the infarcted area was 6.5-fold significantly (p<0.025) higher in the laser-treated pigs vs. control. The c-kit+ cells (stem cells) in the circulating blood of rLLLT pigs was 2.6 and 2.4- fold significantly higher than in the control, 24 and 48 hrs post-MI, respectively. C-kit+ cell density in the infarcted area was also significantly higher in rLLLT pigs than control. ECHO and partial MRI analysis for heart function revealed the left ventricular ejection fraction and fractioning and shortening in the rLLLT pigs to be significantly higher than in the control.
3. Clinical trials
A phase I/II study to apply rLLLT non invasively to the tibia of 15 healthy and 15 diabetic volunteers was approved in April 2014 in Assaf Harofe Medical Center, Israel. This trial intends to test rLLLT safety and ability to increase the levels of stem cells (CD- 34) in the circulating blood following rLLLT therapy. Volunteers are tested before rLLLT and at different time intervals post rLLLT. The optimal power density of the laser delivered on the tibia to induce CD-34 levels as well as the pharmacokinetics of CD-34 in the blood is being determined. Interim data in 13 healthy volunteers (35-50 years of age) show that a single rLLLT application could increase the percent of CD-34 positive cells in the circulating blood (out of total mononucleated cells) 2-4 fold relative to the percent of cells before rLLLT. Study is ongoing.
4. Additional Safety and Efficacy Data
The effect rLLLT was assessed in 93 rats post MI. Data in rats show the same therapeutic effect of rLLLT as seen in swine
rLLLT has shown a remarkable regenerative effect on renal acute and chronic ischemia as could be seen by improved renal biomarkers and histological score following rLLLT therapy (overall 93 rats were expoused mild or acute renal injury)
The safety of multiple applications (twice weekly for the first 2 weeks) of rLLLT was investigated in a long-term (8 months) study in rats (overall 83 mice). No histological differences were observed in the liver, kidneys, brain or BM of the laser-treated rats as compared to the sham-treated, control rats. Moreover, no neoplasmic response in the tissues was observed in the laser-treated groups as compared to the control, sham-treated rats. There were no significant histopathological differences between the same organs under different laser treatment regimes in response to the BM-derived mesenchymal stem cell proliferation following rLLLT to the BM.
Similar reported studies in experimental animals and humans (in similar doses to our studies) have demonstrated no increase in side effects due to LLLT application over the non-laser treated subjects.