Comparison of the Effect of Platelet-Rich Plasma and Simvastatin on Healing of Critical-Size Calvarial Bone Defects.

OBJECTIVE: In previous studies, it has been shown that both simvastatin (chlolesterollowering drug) and platelet-rich plasma (PRP) were capable of promoting bone formation. The aim of this study was to compare the effects of PRP and simvastatin on healing of critical-size bone defects. METHODS: A total of 33 rats (3 for PRP preparation) were used in the experiment. Critical-size defect 8-mm diameter was created in 30 rats' calvarium. Rats were divided into 3 groups. Each group contained 10 animals. In Group A the defect was filled with phosphate-buffered saline only, in Group B with 0.5 mL PRP, and in Group C with 0.1 mg simvastatin. The defects were evaluated by radiographic analysis at 8th and 16th weeks. The animals were sacrificed 16 weeks after the surgery. Histological examination was performed to assess the new bone-forming area. Vessels, fibroblasts, osteoblasts, and osteoclasts were marked in 524749.1-µm area and counted with using Clemex Vision Lite 3.5 Image Analysis program. The results were statistically analyzed.

The effect of combined use of platelet-rich plasma and adipose-derived stem cells on fat graft survival.

BACKGROUND: Free fat grafts have an unpredictable survival rate that limits their successful use. To increase the viability of fat grafts, it is important to minimize the reabsorption rate. OBJECTIVE: Our aim was to investigate whether the combined use of platelet-rich plasma (PRP) and adipose derived stem cells (ADSCs) would contribute an improvement in lower resorption rates of fat grafts. METHODS: Inbred Fischer 344 rats were randomized into 4 groups (n = 10). Fat grafts were mixed with Dulbecco modified Eagle medium in group A, with PRP in group B, with ADSC in group C, and with PRP + ADSC in group D and were injected to the scalp.In vitro growth factor (vascular endothelial growth factor, transforming growth factor-ß, and fibroblast growth factor) levels were compared using enzyme-linked immunoassay method. After 12 weeks weight, volume and histology of the transplants were evaluated. RESULTS: The mean weight and volume of the fat grafts were highest in group D. Histopathological investigations revealed that the number of viable adipocytes and blood vessels were highest in group D. The level of growth factors was significantly higher in stem cell plus PRP group. CONCLUSION: Adipose-derived stem cells combined with PRP can enhance the survival of transplanted fat tissue.

Saving the zone of stasis in burns with melatonin: an experimental study in rats.

BACKGROUND: Studies aimed at recovering the zone of stasis are one of the major issues of experimental burn studies. Many drugs including antithrombotics, anticoagulants, anti-inflammatories have been investigated experimentally for saving the zone of stasis. In this study, the effect of the systemic melatonin on the zone of stasis was evaluated. METHODS: Twenty Wistar Albino rats were used in the study. Rats were assigned to two groups (n=10). The metal comb 1x2 cm in size was immersed in boiling water and held for 20 seconds on the back of the rats to create burn wounds.No treatment was given to the control group. Melatonin was given at a dose of 10 mg/kg/d by intraperitoneal injection in the treatment group for 7 days. Daily digital photographs of both groups were obtained. Total necrotic burn areas and the zone of stasis were assessed with Auto CAD and Visual Analyzing computer programs. At the end of one week, rats were sacrificed and skin biopsies were taken for histological examination. Edema, congestion, inflammatory infiltration, vascular proliferation and fibrosis were the parameters evaluated. Data were evaluated statistically by Chi-square test and Student-t test RESULTS: When histopatologic data and the measured values for total necrotic areas and zone of stasis of the experimental group werecompared to control group, the results were statistically significant (p<0.05). CONCLUSION: According to the results of this study, melatonin is efficient in saving the zone of stasis in burns.