Abstract

Purpose

For effective clinical application of human bone marrow mesenchymal stem cells (hBM-MSCs), the enhancement of their proliferation in vitro together with maintaining the expression of their crucial surface antigens and differentiation potential is necessary. The present study aimed to investigate the effect of light-emitting diode (LED) irradiation on hBM-MSCs proliferation after two, five, or nine days post-irradiation.

Materials and methods

The hBM-MSCs were exposed to the LED light at 630 nm, 4 J/cm², and power densities of 7, 17, or 30 mW/cm². To assess the cell proliferation rate in the sham-irradiated and irradiated samples the cells metabolic activity and DNA content were determined. The number of apoptotic and necrotic cells in the samples was also evaluated. The expression of the crucial surface antigens of the hBM-MSCs up to nine days after irradiation at 4 J/cm² and 17 mW/cm² was monitored with flow cytometry. Additionally, the potential of hBM-MSCs for induced differentiation was measured.

Results

When the metabolic activity was assayed, the significant increase in the cell proliferation rate by 31 and 50% after the irradiation with 4 J/cm² and 17 mW/cm², respectively, was observed at day five and nine when compared to the sham-irradiated cells (p < .05). Similarly, DNA content within the irradiated hBM-MSCs increased by 31 and 41% at day five and nine after the irradiation with 4 J/cm² and 17 mW/cm² in comparison to the sham-irradiated cells. LED irradiation did not change the expression of the crucial surface antigens of the hBM-MSCs up to nine days after irradiation at 4 J/cm² and 17 mW/cm². At the same experimental conditions, the hBM-MSCs maintain in vitro their capability for multipotential differentiation into osteoblasts, adipocytes, and chondrocytes.

Conclusion

Therefore, LED irradiation at a wavelength of 630 nm, energy density 4 J/cm², and power density 17 mW/cm² can effectively increase the number of viable hBM-MSCs in vitro.

中文翻译：

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红光发光二极管照射增加人骨髓间充质干细胞的增殖，保留其免疫表型

摘要

目的

对于人骨髓间充质干细胞 (hBM-MSCs) 的有效临床应用，增强其体外增殖以及维持其关键表面抗原和分化潜能的表达是必要的。本研究旨在研究发光二极管 (LED) 照射对照射后 2、5 或 9 天后 hBM-MSCs 增殖的影响。

材料和方法

hBM-MSC 暴露于 630 nm、4 J/cm ²和 7、17 或 30 mW/cm ²功率密度的 LED 光下。为了评估假照射和照射样品中的细胞增殖率，测定了细胞代谢活性和 DNA 含量。还评估了样品中凋亡和坏死细胞的数量。在以 4 J/cm ²和 17 mW/cm ²照射后长达 9 天，hBM-MSC 的关键表面抗原的表达通过流式细胞术进行监测。此外，还测量了 hBM-MSCs 诱导分化的潜力。

结果

当测定代谢活性时，与假手术相比，在第 5 天和第 9 天观察到在4 J/cm ²和 17 mW/cm ²照射后细胞增殖率分别显着增加了 31% 和 50% - 辐照细胞 ( p  < .05)。类似地，与假照射的细胞相比，在用 4 J/cm ²和 17 mW/cm ²照射后的第 5 天和第 9 天，经照射的 hBM-MSC 中的 DNA 含量增加了 31% 和 41% 。在 4 J/cm ²和 17 mW/cm ²照射后长达 9 天，LED 照射并未改变 hBM-MSC 关键表面抗原的表达. 在相同的实验条件下，hBM-MSCs 在体外保持其多向分化为成骨细胞、脂肪细胞和软骨细胞的能力。

结论

因此，波长为630 nm、能量密度为4 J/cm ²、功率密度为17 mW/cm ^{2 的}LED照射可有效增加体外活hBM-MSCs的数量。