# Healing Effects of Photobiomodulation on Diabetic Wounds
## 4 Photobiomodulation for Diabetic Wound Healing
Covering of wounds with a transparent dressing may be required when performing PBM on wounds, especially when performing PBMT by a contact procedure. This is done to minimize wound damage caused by the tip of the device probe, to prevent cross contamination if irradiating multiple wounds, and to maximize irradiation [68]. [PERSON] and colleagues [68] tested methods for dressing full-thickness excisional wounds that would be suitable for use with PBM in diabetic and nondiabetic mice. The combined use of Tegaderm HP dressing and Cavilon (protects the skin from adhesive stripping) and Masticol (exceptional adhesive properties to benzoin compound tincture) adhesive agents was shown to be efficient for covering wounds of diabetic mice for over 14 days. Irradiated wounds had a very high rate (>80%) of wound splinting (healing occurs mainly by reepithelialization and granulation tissue formation) in diabetic mice, without recourse to invasive treatments, such as sutures. Tegaderm dressing has been shown to transmit 93% of laser light at a wavelength of 532 nm, 94% at 1064 nm, and 74% at 720-800 nm [69; 70]. PBM has also been shown to be successful in human studies, with no reported side effects. [PERSON] et al. [71] showed that PBM may be beneficial in the treatment of DFUs in combination with standard podiatric care and treatment. Patients with type 2 diabetes with a stable or worsening lower extremity ulcer that had been present for a minimum of 4 weeks were enrolled into a pilot study. Patients all received standard podiatric care, which consisted of wound cleaning and debridement, wound dressing, offloading, and infection control (antibiotics) if necessary. Patients were divided into three groups; group 1 received placebo PBM; group 2 received PBM of the ulcer; and group 3 received PBM of the ulcer and regional lymph nodes so as to increase lymph drainage. DFUs were irradiated twice a week for a maximum of 90 days with a LED cluster probe (630 and 850 nm). Ulcers were irradiated after podiatric treatment and before dressing. Wounds in group 2 and 3 healed at a far more rapid rate than wounds in group 1. The results of the study showed that PBM has the potential to stimulate and increase healing rates in combination with podiatric medicine. [PERSON] and colleagues [72] irradiated (660 nm, 3 J/cm\({}^{2}\), 50 mW/cm\({}^{2}\)) non-infected grade I diabetic foot ulcers together with conventional treatments. Wound reduction was measured at two weeks and was found to be significantly reduced in 75% of PBM treated ulcers (30-50%); control wounds showed a decrease in wound area of less than 20% in approximately 80% of ulcers. There was also increased granulation tissue compared to control patients. [PERSON] et al. [73] performed a randomized double-blind controlled clinical trial and treated stage I and II DFUs (685 nm, 50 mW/cm\({}^{2}\), 10 J/cm\({}^{2}\)) six times per week for two weeks, and then every other day until healed. It was found that there was a reduction in ulcer size by the 2 nd and 4 th week. A similar study showed a decrease in ulcer size in type 2 diabetic patients (40.24% as compared with 11.87% for the control group) [74]. [PERSON] et al. [75] treated pressure ulcers, classified as degree III and IV according to the National Pressure Ulcer Advisory Panel (NPUAP), with PBM at 660 nm (100 mW, 2 J/cm\({}^{2}\)) once a day, with intervals of 24 h, for a total of 12 applications. Wound closure analysis revealed improvement of the granulation tissue size up to 50%, and gene analysis of ulcer border tissue obtained through biopsy showed a down-regulation in TN-F\(\alpha\) and up-regulation in VEFG and TGF-\(\beta\). It should be noted that this study did not include controls, however, despite this, PBM still showed promise of being beneficial to diabetic wound healing.