Histological and gene expression analysis of the effects of pulsed low-level laser therapy on wound healing of streptozotocin-induced diabetic rats

Abstract

Diabetes mellitus (DM) is associated with poor wound healing. Studies have shown accelerated wound healing following pulsed low-level laser therapy (LLLT) in non-diabetic animals. The present study aims to evaluate the effect of pulsed LLLT on wound healing in streptozotocin-induced diabetic (STZ-D) rats. We divided 48 rats into two groups of non-diabetic and diabetic. Type 1 DM was induced in the diabetic rat group by injections of STZ. Two, full-thickness skin incisions were made on the dorsal region of each rat. One month after the STZ injection, wounds of the non-diabetic and diabetic rats were submitted to a pulsed, infrared 890-nm laser with an 80-Hz frequency and 0.2 J/cm(2) for each wound point. Control wounds did not receive LLLT. Animals were sacrificed on days 4, 7, and 15 post-injury for histomorphometry and reverse transcription polymerase chain reaction (RT-PCR) analyses of basic fibroblast growth factor (bFGF) gene expression. Pulsed LLLT significantly increased the numbers of macrophages, fibroblasts, and blood vessel sections compared to the corresponding control groups. Semi-quantitative analysis of bFGF gene expression at 48 h post-injury revealed a significant increase in gene expression in both non-diabetic and diabetic rats following LLLT (the ANOVA test). Pulsed LLLT at 0.2 J/cm(2) accelerated the wound healing process in both non-diabetic and diabetic rats as measured by histological characteristics and semi-quantitative bFGF gene expression.

Organic light emitting diode improves diabetic cutaneous wound healing in rats

“…The safety and effectiveness of PBM on wound healing led researchers to investigate the applicability of this treatment for wound healing in in vitro and in vivo diabetic models. Previous research demonstrated that PBM improved diabetic wound healing by accelerating collagen production, enhancing angiogenesis, increasing wound closure rate, and increasing growth factor expression . These results lead to worldwide clinical trials on diabetic wound healing, especially on diabetic foot ulcers …”

“…Previous research demonstrated that PBM improved dia-betic wound healing by accelerating collagen production, 7 enhancing angiogenesis, 8 increasing wound closure rate, [9][10][11] and increasing growth factor expression. 10,12 These results lead to worldwide clinical trials on diabetic wound healing, especially on diabetic foot ulcers. 2,3,13 When proper parameters are established, both laser and light-emitting diode (LED) irradiation improve wound healing implying that the coherence is not essential.…”

The effect of combined pulsed wave low‐level laser therapy and mesenchymal stem cell‐conditioned medium on the healing of an infected wound with methicillin‐resistant Staphylococcal aureus in diabetic rats

“…19 PW LLLT accelerated the wound-healing process in streptozotocin (STZ)-induced TIDM, as measured by tensiometerical parameters and histological characteristics, and significantly reduced the colony-forming units (CFUs) of bacteria in non-genetic rat models of Types 1 and 2. 13,15,16 In 2016, Ranjbar and Takhtfooladi reported positive effects of CWLLLT (685 nm, 3 J/cm 2 , 5 days) on infected burns with MRSA in TIDM animals. 24 Mesenchymal stem cells (MSCs) release growth factors called secrotomes.…”

Improved Wound Remodeling Correlates with Modulated TGF‐beta Expression in Skin Diabetic Wounds Following Combined Red and Infrared Photobiomodulation Treatments

“…These studies have implicated decreased pro‐inflammatory cytokines (TNF α , IL1 β , IL6), mast cell degranulation, altered MMPs and redox status, decreased cell adhesion complexes as well as modulated bFGF signaling as key players in PBM modulated DM wound healing . There have been specific studies designed to assess the effects of wavelengths, dose, light sources (including OLEDs), pulsing as well as combinations with nutritional supplements such as CoQ10 that have all shown positive correlations .…”

“…These studies have implicated decreased pro-inflammatory cytokines (TNFa, IL1b, IL6), mast cell degranulation, altered MMPs and redox status, decreased cell adhesion complexes as well as modulated bFGF signaling as key players in PBM modulated DM wound healing (22)(23)(24)(25)(26)(27). There have been specific studies designed to assess the effects of wavelengths, dose, light sources (including OLEDs), pulsing as well as combinations with nutritional supplements such as CoQ10 that have all shown positive correlations (12,(28)(29)(30)(31)(32)(33)(34)(35)(36). Histological assessment (criteria outlined in Table S2) for re-epithelization and inflammation was performed in each treatment group at day 4 and 10 PBM post-treatments.…”