Preconditioning adipose-derived stem cells with photobiomodulation significantly increased bone healing in a critical size femoral defect in rats.

We assessed the combined impacts of human demineralized bone matrix (hDBM) scaffold, adipose-derived stem cells (hADS), and photobiomodulation (PBM) on bone repair of a critical size femoral defect (CSFD) in 72 rats. The rats were divided into six groups: control (group 1); ADS (group 2 - ADS transplanted into hDBM); PBM (group 3 - PBM-treated CSFDs); ADS + PBM in vivo (group 4 - ADS transplanted into hDBM and the CSFDs were treated with PBM in vivo); ADS + PBM in vitro (group 5 - ADS were treated with PBM in vitro, then seeded into hDBM); and ADS + PBM in vitro+in vivo (group 6 - PBM-treated ADS were seeded into hDBM, and the CSFDs were treated with PBM in vivo. At the anabolic phase (2 weeks after surgery), bone strength parameters of the groups 5, 6, and 4 were statistically greater than the control, ADS, and PBM in vivo groups (all, p = 0.000). Computed tomography (CT) scans during the catabolic phase (6 weeks after surgery) of bone healing revealed that the Hounsfield unit (HU) of CSFD in the groups 2 (p = 0.000) and 5 (p = 0.019) groups were statistically greater than the control group. The groups 5, 4, and 6 had significantly increased bone strength parameters compared with the PBM in vivo, control, and ADS groups (all, p = 0.000). The group 5 was statistically better than the groups 4, and 6 (both, p = 0.000). In vitro preconditioned of hADS with PBM significantly increased bone repair in a rat model of CSFD in vivo.

Combined therapy of adipose-derived stem cells and photobiomodulation on accelerated bone healing of a critical size defect in an osteoporotic rat model.

We investigated the impact of human demineralized bone matrix (hDBM) plus adipose-derived stem cells (hADS) plus photobiomodulation (PBM) on a critical-sized femoral defect (CSFD) in ovariectomy induced osteoporosis in rats. There were 6 groups as follows. In group 1 (control, C), only CSFDs were created. Groups 2-6 were implanted with DBM into the CSFD (DBM-CSFD). In group 2 (S), only DBM was transplanted into the CSFD. In group 3 (S + PBM), the DBM-CSFDs were treated with PBM. In group 4, the DBM-CSFDs were treated with alendronate (S + ALN). In group 5, ADSs were seeded into DBM-CSFD (S + ADS). In group 6, ADSs were seeded into DBM-CSFD and the CSFDs were treated with PBM (S + PBM + ADS). At week eight (catabolic phase of bone repair), the S + ALN, S + PBM + ADS, S + PBM, and S + ADS groups all had significantly increased bone strength than the S group (ANOVA, p = 0.000). The S + PBM, S + PBM + ADS, and S + ADS groups had significantly increased Hounsfield unit than the S group (ANOVA, p = 0.000). ALN, ADS, and PBM significantly increased healed bone strength in an experimental model of DBM-treated CSFD in the catabolic phase of bone healing in osteoporotic rats. However, ALN alone and PBM plus ADS were superior to the other protocols.

Effects of pentoxifylline and alendronate on fracture healing in ovariectomy-induced osteoporosis in rats.

Osteoporosis is determined by decreased bone strength that increases the threat of fractures. The aim of this study was to evaluate the effects of pentoxifylline (PTX) and alendronate (ALN), on the stereological parameters, and gene expression in callus of fracture in an experimental rat model of ovariectomy-induced osteoporosis (OVX). The OVX was induced in 90 female rats. Fourteen weeks later, a complete fracture on the right femur was made. Rats were divided into five groups: 1) control: no treatment; 2) sham: received daily distilled water; 3) daily 3.00 mg kg-1 ALN subcutaneously (SC); 4) daily 200 mg kg-1 PTX (SC) and 5) daily PTX (SC) + ALN (same doses). The osteoclast count was significantly lower in all treatment groups, at 21 and 56 days post-surgery, compared to the control and sham groups. The PTX significantly increased total callus volume at 21 and 56 days post-surgery, compared to the other groups. The PTX+ALN treatment significantly increased both cortical bone volume on day 21, and osteocyte and osteoblast numbers on day 56, compared to the control and sham groups. It can be concluded that PTX and ALN have antiresorptive effects, in OVX rats. Also, PTX has increased the extracellular matrix on both 21 and 56 days after surgery, compared to the other groups. PTX+ALN elevated cortical bone volume on day 21, and osteocyte and osteoblast numbers compared to the control and sham groups on day 56.

Effect of low-level laser therapy on skin fibroblasts of streptozotocin-diabetic rats.

OBJECTIVE: This study explored the effects of low-level laser therapy (LLLT) on cellular changes in cell culture and organ culture of skin from streptozotocin-diabetic (STZ-D) rats. BACKGROUND DATA: Growth of skin and its fibroblasts are impaired in diabetes. Therefore the healing of skin wounds is impaired in diabetic patients. The positive effects of LLLT on complications of diabetes in patients and animal models have been shown. METHODS: Diabetes was induced in rats by streptozotocin 30 days after its injection. Two sets of skin samples were extracted from skin under sterile conditions. Fibroblasts that were extruded from the samples were proliferated in vitro, and another set of samples were cultured as organ culture. A 24-well culture medium containing Dulbecco's modified minimum essential medium was supplemented by 12% fetal bovine serum. There were five laser-treated and five sham-exposed groups. A helium-neon laser was used, and 0.9-4 J/cm(2) energy densities were applied four times to each organ culture and cell culture. The organ cultures were analyzed by light microscopy and transmission electron microscopy examinations. Cell proliferation was evaluated by dimethylthiazol-diphenyltetrazolium bromide (MTT) assay. RESULTS: Statistical analysis revealed that 4-J/cm(2) irradiation significantly increases the fibroblast numbers compared to the sham-exposed cultures (p = 0.046). CONCLUSION: It is concluded that LLLT resulted in a significant increase of fibroblast proliferation of STZ-D rats in vitro.

Low-level laser therapy using 80-Hz pulsed infrared diode laser accelerates third-degree burn healing in rat.

OBJECTIVE: To evaluate 80-Hz pulsed infrared diode low-level laser therapy (LLLT) for third-degree burn healing in rats. BACKGROUND DATA: Review of the literature indicates that LLLT has a biostimulatory effect on wound healing, although no clear recommendation can be made yet. METHODS: Forty-eight male rats were divided into groups 1 and 2. On day 0, three third-degree burns were made on the dorsum of each rat using steam. In group 1, the first burn was exposed to an 80-Hz pulsed 890-nm infrared diode laser at 0.396 J/cm2 three times a week. In group 2, the first burn was exposed to the inactivated laser. In both groups, the second burns were treated with topical application of nitrofurazone 0.2%, and third burns did not receive any treatment and were considered as control burns. Burns were clinically examined. The rats were treated for 8, 12, and 20 days in both groups. On days 8, 2, and 20, microbiological samples of burns were collected and analyzed. Data were analyzed using the chi-square method. RESULTS: The paired Student t-test showed that the wound closure rate of laser-treated burns (17.6+/-1.86 days) was significantly longer than that of the control burns (19.6+/-0.81 days) (p=0.007).The number of laser-treated burns that closed was significantly higher than controls. Chi-square tests showed that there was not significant difference between each microorganism (Staphylococcus epidermis, S. aureus and Pseudomonas aeruginosa). CONCLUSION: LLLT using an 80-Hz pulsed infrared diode laser accelerated third-degree burn healing in rat.