Investigation of the effects of umbilical cord-derived mesenchymal stem cells and curcumin on Achilles tendon healing - can they act synergistically?

BACKGROUND: It is known that curcumin and umbilical cord-derived mesenchymal stem cells (UC-MSCs) positively affect experi-mental tendon injury healing. This study investigated individual effects and potential synergistic effects of using curcumin and UC-MSCs alone and together. METHODS: Eighty female Wistar albino rats were randomly divided into five groups: Control, curcumin, sesame oil, MSCs, and Curcumin+MSCs groups. In all rats, punch tendon defect was created in both right and left Achilles tendons. While no additional treatment was applied to the control group, curcumin, sesame oil used as a solvent for curcumin, MSCs, and MSCs and curcumin com-bination were applied locally to the injury site, respectively, in the other groups. Curcumin was solved in sesame oil before application. In each group, half of the animals were euthanized in the post-operative 2nd week while the other half were euthanized in the post-operative 4th week. The right Achilles was used for biomechanical testing, while the left Achilles was used for histological evaluation and immunohistochemical analysis of type I, Type III collagen, and tenomodulin. RESULTS: Histologically, significant improvement was observed in the curcumin, MSCs, and Curcumin+ MSCs groups compared to the control Group in the 2nd week. In the 2nd and 4th weeks, Type III collagen was significantly increased in the curcumin group com-pared to the control group. In week 4, tenomodulin increased significantly in the curcumin and MSCs groups compared to the control group. Tendon tensile strength increased significantly in MSCs and Curcumin+MSCs groups compared to the control group in the 4th week. No superiority was observed between the treatment groups regarding their positive effects on recovery. CONCLUSION: Locally used curcumin and UC-MSCs showed positive effects that were not superior to each other in the healing of injury caused by a punch in the Achilles tendons of rats. However, synergistic effects on healing were not observed when they were applied together.

The effect of TENS on random pattern flap survival in nicotinized rats.

The adverse effects of cigarettes, due to their nicotine content, may cause important ischemic complications in flaps. Electrical stimulation increases blood flow in ischemic tissues, the level of vascular endothelial growth factor, capillary density, and angiogenesis while decreasing oxygen tension in tissues. Electrical stimulation is also known to increase survival rate in flaps. In this study, which tests the hypothesis that TENS (a type of electrical stimulation) contributes to enhancement of flap viability by eliminating the adverse effects of nicotine, 40 rats were divided into 4 groups of 10 rats. Nicotinization was achieved by subcutaneous administration of 2 mg/kg per day to the rats, other than those in the Control group, for 4 weeks. The rats in one of the nicotinized groups received 20 mA, 80 Hz TENS (TENS1 group) for 1 hour daily throughout the last week before McFarlane flaps of random pattern were made in the backs of all the rats. Another nicotinized group was subjected to TENS in a similar dose after flap elevation (TENS2 group). Flap blood flow was measured before and 48 hours after their construction, and their fluorescein perfusion was measured immediately after the flap elevation. The comparison of the survival rates of the flaps revealed that, although the blood flow in the Nicotine group was significantly lower than in the Control group, it was significantly higher in the TENS1 group than in both the Control and Nicotine groups. The proportion of the area stained with fluorescein, immediately after the elevation of flaps, was significantly reduced in the Nicotine group compared to the Control group. In the TENS1 group, however, it was greater than in the nicotine and TENS2 groups. Flap viability rates decreased significantly in the Nicotine group compared with the Control group. In the TENS2 group, however, an increase was observed compared with the Nicotine group.These findings suggest that although TENS performed before flap elevation does not contribute to flap survival, despite causing a rise in blood flow, it enhances flap survival when applied postoperatively. Given the practicality and low cost of TENS, it can be concluded that it may be possible to use it in the management of ischemic complications in flap operations in smokers.

Flap Preconditioning by Electrical Stimulation as an Alternative to Surgical Delay: Experimental Study.

Partial flap failures are unpredictable complications of reconstructive surgery. Electrical stimulation increases blood flow, capillary density, angiogenesis and vascular endothelial growth factor, anti-inflammatory effects while decreasing oxygen tension in tissues. In this study, we investigated these effective properties of electrical stimulation preoperatively on flap surgery instead of the surgical delay procedure.Modified McFarlane flaps were raised on the backs of 50 Sprague-Dawley rats. In the control group, a skin flap was made and flap survival rate was assessed on the seventh day. In the surgical delay group, 14 days after creating the bipedicled flap, the flap was totally elevated and flap survival rate was assessed on the 21st day. In the preconditioning by electrical stimulation group, the flap was created after application of electrical stimulation for 7 days. Flap survival rate was assessed on the 14th day. In the electrically stimulated ischemic flap group, the flap was created and afterward, electrical stimulation was applied for 7 days. After that, flap survival rate was assessed on the seventh day. In the surgical delay plus electrical stimulation group, following the elevation and suturing of the bipedicled flap back into its bed, electrical stimulation was applied in the first 7 days of delay, the flap was created on the 14th day, and then flap survival rate was assessed on the 21st day. In all groups, blood flow was evaluated at particular times. After completing these procedures, the flap vascularities of 5 animals from each group were assessed with microangiography.The flap survival rate of the preconditioning by electrical stimulation group was significantly higher than those of the other groups (P < 0.05). According to the blood flow estimates, except the preconditioning by electrical stimulation group and surgical delay plus electrical stimulation group, blood flow decreased in all the other groups after the postprocedure. In the microangiographic assessment of the preconditioning by electrical stimulation group, there were thin but numerous networks like vascular structures.Electrical stimulation applied to the normal area before flap elevation increased the flap survival. This increase is paramount to surgical delay which is, so far, widely known as the most effective method of improving flap vascularity.

Role of thymus oil in burn wound healing.

Thymus oil and its components are becoming increasingly popular as naturally occurring antimicrobial and antioxidant agents. The real importance of thymus on nitric oxide (NO) is unknown. NO is an important mediator in numerous physiologic and pathophysiologic events. Stasis and thrombosis in burn wound can progress as a result of the release of local mediators. The implication of NO in burn injury is not well studied. In this study, we tried to determine the role of burn-induced NO and whether thymus oil plays a protective role after a thermal injury. Rats were divided into five groups. We topically applied thymus oil, olive oil, and silverdin and sulfadiazine on the rats, respectively, during a period of 21 days after they were burned while under anesthesia. The burned control group and nonburned control group did not receive any treatment. The results of this study show that NO was overproduced by thermal injury and decreased during the days after burn injury. The decrease in rats treated with thymus and sulfadiazine was higher than the others. These data indicate that thymus oil may serve as a protective agent to the damaged tissues by decreasing the NO level. Histologic examination results show that the formation of new tissue in rats receiving thymus oil was more than other burned groups, and this finding supports our hypothesis.