No abstract

Osteoporosis (OP) and osteoporotic fracture are major public health issues for society; the burden for the affected individual is also high. Previous studies have shown that pulsed wave low-level laser therapy (PW LLLT) has osteogenic effects. This study intended to evaluate the impacts of PW LLLT on the cortical bone of osteoporotic rats' tibias in two experimental models, ovariectomized and dexamethasone-treated. We divided the rats into four ovariectomized induced OP (OVX-d) and four dexamethasone-treated (glucocorticoid-induced OP, GIOP) groups. A healthy (H) group of rats was considered for baseline evaluations. At 14 weeks following ovariectomy, we subdivided the OVX-d rats into the following groups: (i) control which had OP, (ii) OVX-d rats treated with alendronate (1 mg/kg), (iii) OVX-d rats treated with LLLT, and (iv) OVX-d rats treated with alendronate and PW LLLT. The remaining rats received dexamethasone over a 5-week period and were also subdivided into four groups: (i) control rats treated with intramuscular (i.m.) injections of distilled water (vehicle), (ii) rats treated with subcutaneous alendronate injections (1 mg/kg), (iii) laser-treated rats, and (iv) rats simultaneously treated with laser and alendronate. The rats received alendronate for 30 days and underwent PW LLLT (890 nm, 80 Hz, 0.972 J/cm(2)) three times per week during 8 weeks. Then, the right tibias were extracted and underwent a stereological analysis of histological parameters and real-time polymerase chain reaction (RT-PCR). A significant increase in cortical bone volume (mm(3)) existed in all study groups compared to the healthy rats. There were significant decreases in trabecular bone volume (mm(3)) in all study groups compared to the group of healthy rats. The control rats with OP and rats from the vehicle group showed significantly increased osteoclast numbers compared to most other groups. Alendronate significantly decreased osteoclast numbers in osteoporotic rats. Concurrent treatments (compounded by PW LLLT and alendronate) produce the same effect on osteoporotic bone.

No abstract

Herein, we attempted to evaluate the therapeutic potential of photobiomodulation (PBM) and curcumin-loaded iron nanoparticles (CUR), alone and in combination, on wound closure rate (WCR), microbial flora by measuring colony-forming units (CFUs), the stereological and biomechanical properties of repairing wounds in the maturation stage of the wound healing course in an ischemic infected delayed healing wound model (IIDHWM) of type I diabetic (TIDM) rats. There were four groups: group 1 was the control, group 2 received CUR, rats in group 3 were exposed to PBM (80 Hz, 890 nm, and 0.2 J/ cm 2 ), and rats in group 4 received both PBM and CUR (PBM + CUR). We found CFU was decreased in groups 2, 3, and 4 compared to group 1 (p = 0.000 for all). Groups 2, 3, and 4 showed a considerable escalation in WCR compared to group 1 (p = 0.000 for all). In terms of wound strength parameters, substantial increases in bending stiffness and high-stress load

Photobiomodulation (PBM) and stem cell-based treatments are relatively invasive methods for treating bone defects. Specific and oriented cellular and molecular functions can be induced by applying an appropriate type of PBMT and ADSs. This study aimed to explore the role of MicroRNAs in the PBM & hADS-based treatments in improving the mechanical and cellular properties of a critical size fracture in a rat model. A critical size femoral defect (CSFD) is induced in both femoral bones of 24 rats. Then a human demineralized bone matrix scaffold (hDBMS) was engrafted into the CSFDs of all rats. Experiments are performed on 4 groups (12 rats per group): (1) Control (hDBMS); (2) hDBMS + hADS, hADS was engrafted into CSFDs; (3) hDBMS + PBM, the CSFD was exposed to PBM(810 nm wavelength, 1.2 J/cm2 energy density); (4) hDBMS+(hADS + PBM), hADSs were implanted into CSFD then were exposed to PBM. At 42 days after CSFD induction, the rats were killed and, the left and right CSFDs were removed for the mechanical compression tests, and molecular and cellular studies, respectively. The results indicate that miRNA-26a, BMP, SMAD, RUNX, and OSTREX were more expressed in the treated groups than in the control group. Furthermore, the biomechanical and histological properties of CSFDs in treated groups were better than the control group. The correlation tests revealed a positive relationship between microRNA and improving biomechanical and cellular parameters of CSFDs in the rat model. We concluded that MicroRNA-26 plays a significant role in the hADS, PBM, and hADS + PBM-based healing of CSFDs in rats.