Low-level laser irradiation promotes proliferation of cryopreserved adipose-derived stem cells

Abstract

Objective To evaluate the effect of low-level laser irradiation on proliferation and viability of murine adipose-derived stem cells previously submitted to cryopreservation.Methods Adipose-derived stem cells were isolated from inguinal fat pads of three mice, submitted to cryopreservation in fetal bovine serum with 10% dimethylsulfoxide for 30 days and then thawed and maintained in normal culture conditions. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at zero and 48 hours, using two different energy densities (0.5 and 1.0J/cm2). Cell proliferation was evaluated by trypan blue exclusion method and MTT assay at intervals of zero, 24, 48, and 72 hours after the first laser application. Cell viability and apoptosis of previously cryopreserved cells submitted to laser therapy were evaluated by flow cytometry.Results The Irradiated Groups (0.5 and 1.0J/cm2) showed an increased cell proliferation (p<0.05) when compared to the Control Group, however no significant difference between the two energy densities was observed. Flow cytometry revealed a percentage of viable cells higher than 99% in all groups.Conclusion Low-level laser irradiation has stimulatory effects on the proliferation of adipose-derived stem cells previously submitted to cryopreservation.

Low‐level laser and adipose‐derived stem cells altered remodelling genes expression and improved collagen reorganization during tendon repair

“…32 No difference was observed in the amounts of PCNA, a marker of cell proliferation, although some studies demonstrate the performance of ASCs in increased cell proliferation in tendon repair. 8,12,33 A study of Dex et al 34 also demonstrates the role of Tnmd in the maturation of collagen fibres. Therefore, although no significant difference was detected in the protein quantification of Tnmd, there was a trend towards a higher amount of Tnmd in the L, SCL, SC and T groups, respectively, corroborating the higher degree of organization of the collagen fibres.…”

“…7,8,39 After lesion, the release of several growth factors and cytokines during the inflammation process is responsible for activation of genes responsible for the matrix remodelling. 7,8,39 After lesion, the release of several growth factors and cytokines during the inflammation process is responsible for activation of genes responsible for the matrix remodelling.…”

“…Shen et al 30 also observed increased collagen I and III in a co-culture system of corneal stromal cells and ASCs, corroborating with our data.During the calcaneus tendon repair using LLL, a study of Abid and Abid 31 demonstrated a higher collagen deposition and significant number of tenocytes. No difference was observed in the amounts of PCNA, a marker of cell proliferation, although some studies demonstrate the performance of ASCs in increased cell proliferation in tendon repair 8. The lower amount of collagen I in the SCL group in relation to the T group may be related to the lower expression of Scx in SCL Scx is a transcription factor that directly regulates the gene expression of collagen I in tendons 29.…”

“…5,6 Researches about the treatment of tendon injuries using adipose-derived mesenchymal stem cells (ASCs) show a better organization of collagen bundles, as well as improved biomechanics and gait on treated animals. 8 Thus, the combination of LLL and ASCs in vivo could induce a greater proliferation of these cells in the injured region, considering small the percentage of ASCs that survive at the injury site after application. 7 Low-level laser therapy promotes tissue repair mainly due to its anti-inflammatory effect, but also has a mitogenic potential.…”

“…6 The photobiostimulation promoted by the low-level laser (LLL) has attracted the attention of researchers in recent years, already being used in clinical practice for the treatment of tendinous and post-operative injuries, accelerating the repair process, with the improvement of the tissue reorganization. 9 Although some in vitro studies demonstrate the efficiency of LLL treatment combined with MSCs, 8,[10][11][12] the literature is scarce considering the association of both therapies in vivo. 8 Thus, the combination of LLL and ASCs in vivo could induce a greater proliferation of these cells in the injured region, considering small the percentage of ASCs that survive at the injury site after application.…”