In vitro inhibition of uterine contractions using electrospun nanofibers loaded with nifedipine and ML7.

OBJECTIVE: To formulate a nanofiber-based controlled drug delivery system that could be effective in preventing uterine contractions and can be used for the treatment of preterm labor. PATIENTS AND METHODS: We utilized uterine tissue samples obtained from ten pregnant women who underwent cesarean section at term to investigate the effect of nanofibers on spontaneous and induced myometrial contractions. We prepared nifedipine and ML7-loaded nanofibers using the electrospinning method with Poly(D,L-lactide-co-glycolide) (PLGA) polymer, resulted in seven groups of nanofibers, including a control group. Group I served as the control, Group II was non-drug loaded nanofiber, Group III was nifedipine (10-5 M) loaded nanofiber, Group IV was ML7 (3x10-5 M) loaded nanofiber, Group V was ML7 (3x10-5 M) and nifedipine (10-5 M) nanofiber, Group VI was ML7 (3x10-5 M) and nifedipine (3x10-5 M) nanofiber, and Group VII was ML7 (3x10-5 M) and nifedipine (10-4 M) nanofiber. To evaluate the contractile response, the nanofibers loaded with different doses of ML7 and nifedipine were applied onto the tissue strips, and in vitro organ bath experiments were performed. Full-thickness uterine samples were cleared of the serosa and surrounding tissues, and eight strips (3x10 mm) were prepared from each sample. The seven different nanofiber formulations were gently placed and sutured onto the strips, with one strip always kept as the time control. We recorded spontaneous, KCl-induced, and stimulated cumulative oxytocin-induced contractions from all samples in all groups. After completing all experiments, the viability of the strips was checked, and weight measurement was recorded. RESULTS: The administration of drug-loaded polymers resulted in a significant decrease in both the frequency and intensity of spontaneous and induced contractions in all groups (p<0.01). No significant difference was observed between the control group and the non-drug-loaded nanofiber group in post hoc analysis (p=0.704). In terms of amplitude and frequency of contractions, the most significant decrease was observed in group VII at cumulative oxytocin doses compared to the control and non-drug-loaded nanofiber groups (p<0.05). Moreover, group VI also showed a significant decrease in contraction intensity and frequency compared to the control and non-drug-loaded nanofiber groups (p<0.05). While the use of nifedipine and/or ML7-loaded nanofibers decreased both intensity and frequency of contraction, this attenuation was not significant compared to the control and empty polymer groups. However, a more significant inhibition was observed when ML7 was used with nifedipine at doses of 3x10-5 M and 10-4 M. CONCLUSIONS: The results indicate that human uterine contractions can be inhibited using calcium channel blocker (nifedipine) and myosin light chain kinase inhibitor (ML7) loaded nanofibers in uterine tissue strips. These results strongly suggested the potential for the development of locally effective and safe controlled drug release systems to prevent premature birth.

Role of telocytes in the pathogenesis of ectopic pregnancy.

OBJECTIVE: The aim of this study is to investigate the effect of telocytes on tubal motility in ectopic pregnancies. PATIENTS AND METHODS: This study included patients with ectopic pregnancy (EP) (n=10) and control patients (n=10) (partial salpingectomy for contraception). Immunohistochemical staining for c-Kit, vimentin, CD34 and S100A was performed to quantify telocytes in the mucosa, muscular layer and serosa of fallopian tubes of control and EP group. Spontaneous and KCl- (80 mM) induced contraction and cumulative progesterone dose-relaxation (10-11-10-5 M) and cumulative oxytocin dose-contraction (10-10-10-4 M) responses were recorded. RESULTS: The groups were comparable in terms of age, gravida, parity, delivery type and gestational week (p>0.05). The homogenous distribution of telocytes in the mucosa and muscular layers of the control group, changed to heterogeneous localization the EP group. Immunohistochemical staining with vimentin, S100A, c-Kit and CD34, revealed increased telocyte counts in the muscular layer and serosa of the tubal tissues of EP. The frequency of the spontaneous contractions was higher in the control group (p<0.001); contrarily, the amplitude of the contractions was higher in ectopic pregnancies (p<0.001). Although the cumulative oxytocin dose-contraction curves were similar at all concentrations (p>0.05), the cumulative progesterone dose-relaxation curves exhibited higher relaxation response in the EP group at all concentrations (p<0.001). CONCLUSIONS: Increased telocyte count in the fallopian tube may decrease tubal motility and may affect the transfer of the blastocyst to the uterus and possibly contribute to the pathogenesis of EP.

Effect of stress on erythrocyte deformability, influence of gender and menstrual cycle.

This study aimed to investigate the effect of acute mental stress on erythrocyte deformability (ED) in women during different phases of the menstrual cycle and to compare the results with men. For this purpose, healthy males (n=10) and females (n=10) (during follicular and luteal phases) underwent Stroop color-word interference and cold pressor tests. Hemoglobin, hematocrit and leukocyte counts before and after this stress test revealed no difference in either group; erythrocyte sedimentation rate was significantly lower in the post-test samples in all. In all groups erythrocyte filtration time was significantly higher and thus ED was significantly lower after the stress test (mean+/-SEM, PRE-TEST: follicular: 3.08+/-0.05; luteal: 2.07+/-0.05; men: 2.9+/-0.05) (POST-TEST: follicular: 4.5+/-0.07; luteal: 4.1+/-0.07; men: 4.39+/-0.1). ED was appreciably influenced by gender and menstrual cycle. Women at the luteal phase had better ED compared to both women at the follicular phase and men, the effect being especially pronounced in the pre-test samples. Our results suggest that stress may induce cardiovascular diseases by lowering ED in both genders. The effect of stress on ED varies with gender and during different phases of the menstrual cycle, which may be explained by variations in the sex hormones.

Impact of stress, gender and menstrual cycle on immune system: possible role of nitric oxide.

Stress is a factor found to be involved in the etiology of many diseases. Gender and menstrual cycle phases are other factors affecting the predisposition of individuals for certain diseases. Results from animal and human studies suggest that the distribution of immune system cells may change at different phases of the menstrual cycle. Acute mental stress in humans alters immune variables, too. The increase in the number of natural killer (NK) cells is the most consistent finding among the immune variables, though there are controversies for the other lymphocyte groups. Nitric oxide (NO) as an immune mediator has an unsettled role whether it causes the redistribution of the immune cells, or is an end product of lymphocyte activation. This study was planned to investigate the effect of mental stress on lymphocyte subtypes and the role of NO, for men and women at different phases of the cycle. For this purpose, healthy men (n = 10) and women (n = 10), during the follicular and luteal phases underwent Stroop colour-word interference and cold pressor tests. The immune system responses before and after the tests were determined by cell counts with the flowcytometer. Menstrual cycle phase was ascertained by plasma estrogen and progesterone measurements. Stress response was evaluated by blood pressure (BP) and heart rate (HR) measurements throughout the tests and plasma cortisol and urinary metanephrine and vanillylmandelic acid (VMA) measurements before and after the tests. Plasma and urinary NO determinations were performed before and after the test was completed. All the results were analysed with the appropriate statistical methods. The luteal phase differed from the other groups due to the presence of suppressed immune response to acute stress, including decreased CD4/CD8 ratio and NK cell percentage. On the other hand, acute stress caused a shift from cellular to humoral immunity in men. As indicated by these results, individual reaction towards stress is affected by gender and menstrual cycle phase. NO appears to be a possible effector molecule for these differences.