Photobiomodulation (PBM), especially in the red wavelength range, has been demonstrated to be an effective treatment option for superficial and chronic wounds. However, ischemia and subsequent reperfusion can further challenge wound healing. Therefore, we investigated the effect of pulsed red LED light at 635 nm on cellular function in an in-vitro model of hypoxia/reoxygenation (H/R) challenge.

Mouse myoblasts and fibroblasts were incubated in oxygen-deprived starvation medium (hypoxia) for 3 h after which the media was changed to oxygenated, fully supplemented media to simulate reperfusion. Cells were then treated with pulsed red LED light at a wavelength of 635 nm at 40 mW/cm². Mitochondrial respiratory activity, ATP production and ROS levels were analysed immediately post-illumination. The effects on cellular metabolic activity and proliferation were measured at 6 h and 24 h and apoptosis/necrosis was measured at 24 h post-illumination.

Our results show that both cell types reacted differently to H/R challenge and PBM. PBM of H/R-challenged cells enhanced mitochondrial activity and rescued decreased ATP levels, with significant effects in fibroblasts. This was associated with increased cell proliferation rates in both cell types. The increase was again more pronounced in fibroblasts.

Our study concluded that PBM with red LED light significantly restored ATP levels during H/R and effectively promoted cell growth under both normoxic and H/R conditions. In clinical applications, PBM has been repeatedly reported to resolve difficult clinical situations in which ischemia/reperfusion injuries are a major issue. Our study confirms the beneficial effects of PBM especially in H/R-challenged cells.

光生物调节（PBM），特别是在红色波长范围内，已被证明是浅表和慢性伤口的有效治疗选择。但是，缺血和随后的再灌注会进一步挑战伤口的愈合。因此，我们在缺氧/复氧（H / R）挑战的体外模型中研究了635 nm的脉冲红色LED光对细胞功能的影响。

将小鼠成肌细胞和成纤维细胞在缺氧的饥饿培养基（缺氧）中孵育3 h，然后将培养基更改为充氧的，完全补充的培养基以模拟再灌注。然后将细胞用波长为635 nm，波长为40 mW / cm ^2的脉冲红色LED光处理。照明后立即分析线粒体呼吸活性，ATP产生和ROS水平。在照射后6小时和24小时测量对细胞代谢活性和增殖的影响，并在照射后24小时测量细胞凋亡/坏死。

我们的结果表明，两种细胞对H / R挑战和PBM的反应不同。H / R挑战细胞的PBM增强了线粒体活性并挽救了降低的ATP水平，对成纤维细胞具有显着影响。这与两种细胞类型中细胞增殖速率的增加有关。成纤维细胞中的增加再次更加明显。

我们的研究得出结论，带有红色LED灯的PBM在H / R期间可显着恢复ATP水平，并在常氧和H / R条件下有效促进细胞生长。在临床应用中，PBM已经被反复报道以解决其中缺血/再灌注损伤是主要问题的困难临床情况。我们的研究证实了PBM的有益作用，尤其是在H / R挑战的细胞中。