Low level laser irradiation stimulates osteogenic phenotype of mesenchymal stem cells seeded on a three-dimensional biomatrix

Abstract

Mesenchymal stem cells (MSCs) seeded on three-dimensional (3D) coralline (Porites lutea) biomatrices were irradiated with low-level laser irradiation (LLLI). The consequent phenotype modulation and development of MSCs towards ossified tissue was studied in this combined 3D biomatrix/LLLI system and in a control group, which was similarly grown, but was not treated by LLLI. The irradiated and non irradiated MSC were tested at 1-7, 10, 14, 21, 28 days of culturing via analysis of cellular distribution on matrices (trypan blue), calcium incorporation to newly formed tissue (alizarin red), bone nodule formation (von Kossa), fat aggregates formation (oil red O), alkaline phosphatase (ALP) activity, scanning electron microscopy (SEM) and electron dispersive spectrometry (EDS). The results obtained from the irradiated samples showed enhanced tissue formation, appearance of phosphorous peaks and calcium and phosphate incorporation to newly formed tissue. Moreover, in irradiated samples ALP activity was significantly enhanced in early stages and notably reduced in late stages of culturing. These findings of cell and tissue parameters up to 28 days of culture revealed higher ossification levels in irradiated samples compared with the control group. We suggest that both the surface properties of the 3D crystalline biomatrices and the LLLI have biostimulatory effects on the conversion of MSCs into bone-forming cells and on the induction of ex-vivo ossification.

Initial effects of low-level laser therapy on growth and differentiation of human osteoblast-like cells

“…Early in vivo studies on bone regeneration after LLLT treatment showed increased bone deposition after tooth extraction, suggesting enhancing effects of LLLT on ossification [17]. These findings are supported by the in vitro observation that LLLT significantly increased cellular proliferation, bone nodule formation and alkaline phosphatase (ALP) activity of rat calvarial cells [18], and enhanced the osteogenic differentiation of murine mesenchymal stem cells [19]. Furthermore, animal studies demonstrated that LLLT enhances the functional attachment of titanium implants to bone and promotes bone healing and mineralization [20].…”

Effects of low‐level laser therapy on proliferation and differentiation of murine bone marrow cells into osteoblasts and osteoclasts

“…Several studies using various approaches have shown no difference between laser and control groups regarding the expression of osteonectin [16], alkaline phosphatase activity, osteocalcin, and TGF-b1 [4]. Some studies reported slight effects on alkaline phosphatase activity [17], osteoglycine [18], osteopontin, and bone sialoprotein expressions [19]. In our experiments we have evaluated the expression of six classical osteoblastic differentiation markers by quantitative RT-PCR.…”

Low‐energy laser irradiation promotes synovial fibroblast proliferation by modulating p15 subcellular localization

“…The reported safe beneficial effects of LELI for bone and joint conditions include stimulating the repair of fractures or bone injury [47,48], suppression of inflammation in rheumatoid arthritis [49] and Achilles tendonitis [50], repair or protection of articular cartilage [12,51], conversion of MSCs to bone-forming cells [52], and pain reduction in elbow tendinopathy [53] and low-back pain [54]. However, the mechanism underlying the effect is not understood, and thus decisions regarding irradiation parameters for LELI have remained subjective [53,54].…”