Comparison of hyaluronate/carboxymethylcellulose membrane and melatonin for prevention of adhesion formation in a rat model

OUP accepted manuscript

BACKGROUND

To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones produced by the ovaries. Mature oocytes may be fertilized in the fallopian tubes, and the resulting zygote is transported toward the uterus, where it can implant and continue developing. The cervix acts as a physical barrier to protect the fetus throughout pregnancy, and the vagina acts as a birth canal (involving uterine and cervix mechanisms) and facilitates copulation. Fertility can be compromised by pathologies that affect any of these organs or processes, and therefore, being able to accurately model them or restore their function is of paramount importance in applied and translational research. However, innate differences in human and animal model reproductive tracts, and the static nature of 2D cell/tissue culture techniques, necessitate continued research and development of dynamic and more complex in vitro platforms, ex vivo approaches and in vivo therapies to study and support reproductive biology. To meet this need, bioengineering is propelling the research on female reproduction into a new dimension through a wide range of potential applications and preclinical models, and the burgeoning number and variety of studies makes for a rapidly changing state of the field.

OBJECTIVE AND RATIONALE

This review aims to summarize the mounting evidence on bioengineering strategies, platforms and therapies currently available and under development in the context of female reproductive medicine, in order to further understand female reproductive biology and provide new options for fertility restoration. Specifically, techniques used in, or for, the uterus (endometrium and myometrium), ovary, fallopian tubes, cervix and vagina will be discussed.

SEARCH METHODS

A systematic search of full-text articles available in PubMed and Embase databases was conducted to identify relevant studies published between January 2000 and September 2021. The search terms included: bioengineering, reproduction, artificial, biomaterial, microfluidic, bioprinting, organoid, hydrogel, scaffold, uterus, endometrium, ovary, fallopian tubes, oviduct, cervix, vagina, endometriosis, adenomyosis, uterine fibroids, chlamydia, Asherman’s syndrome, intrauterine adhesions, uterine polyps, polycystic ovary syndrome and primary ovarian insufficiency. Additional studies were identified by manually searching the references of the selected articles and of complementary reviews. Eligibility criteria included original, rigorous and accessible peer-reviewed work, published in English, on female reproductive bioengineering techniques in preclinical (in vitro/in vivo/ex vivo) and/or clinical testing phases.

OUTCOMES

Out of the 10 390 records identified, 312 studies were included for systematic review. Owing to inconsistencies in the study measurements and designs, the findings were assessed qualitatively rather than by meta-analysis. Hydrogels and scaffolds were commonly applied in various bioengineering-related studies of the female reproductive tract. Emerging technologies, such as organoids and bioprinting, offered personalized diagnoses and alternative treatment options, respectively. Promising microfluidic systems combining various bioengineering approaches have also shown translational value.

WIDER IMPLICATIONS

The complexity of the molecular, endocrine and tissue-level interactions regulating female reproduction present challenges for bioengineering approaches to replace female reproductive organs. However, interdisciplinary work is providing valuable insight into the physicochemical properties necessary for reproductive biological processes to occur. Defining the landscape of reproductive bioengineering technologies currently available and under development for women can provide alternative models for toxicology/drug testing, ex vivo fertility options, clinical therapies and a basis for future organ regeneration studies.

Melatonin: the dawning of a treatment for fibrosis?

Fibrosis is a common occurrence following organ injury and failure. To date, there is no effective treatment for this condition. Melatonin targets numerous molecular pathways, a consequence of its antioxidant and anti-inflammatory actions that reduce excessive fibrosis. Herein, we review the multiple protective effects of melatonin against fibrosis. There exist four major phases of the fibrogenic response including primary injury to the organ, activation of effector cells, the elaboration of extracellular matrix (ECM) and dynamic deposition. Melatonin regulates each of these phases. Additionally, melatonin reduces fibrosis levels in numerous organs. Melatonin exhibits its anti-fibrosis effects in heart, liver, lung, kidney, and other organs. In addition, adhesions which occur following surgical procedures are also inhibited by melatonin. The information reviewed here should be significant to understanding the protective role of melatonin against fibrosis, contribute to the design of further experimental studies related to melatonin and the fibrotic response and shed light on a potential treatment for fibrosis.

A systemic review of randomized controlled studies about prevention with pharmacologic agents of adhesion formation in the rat uterine horn model

INTRODUCTION

Evaluation of treatment attempts in postoperative adhesion formation is pivotal for the prevention of several morbidities including infertility, pelvic pain, bowel obstruction, and subsequent intraoperative complications. The purpose of this systemic review was to assess the literature on the rat uterine horn model for adhesion formation and treatment modalities to prevent adhesion in the most frequently used experimental animal model.

MATERIAL AND METHODS

We performed a systemic review of publications from January 1(st) 2000 to December 31(st) 2013 via a PubMed search. A high number of agents were evaluated for the prevention of postoperative adhesion formation in the rat uterine horn model.

RESULTS

According to most of the studies, adjuvants such as antiinflamatuars, antiestrogens, antioxidants were effective to prevent adhesion formation.

CONCLUSIONS

Prevention of adhesion formation is pivotal and numerous types of agents were described in the literature were summarized in this review.

Intraperitoneal Nigella sativa for prevention of postoperative intra-abdominal adhesions in rats

OBJECTIVE

To evaluate intraperitoneal administration of Nigella sativa (NS) to prevent postoperative intraperitoneal adhesion (PPA) after surgical manipulation of rat uterine horn.

MATERIALS AND METHODS

Two forms of NS were used in the study (Volatile oil (NSVO) and the ethanolic extract (NSEE)). A total of 50 rats were randomly assigned to the sham group (n = 10), control group (n = 10), NSVO group (n = 10), NSEE group (n = 10), and the Seprafilm group(n = 10). After 14 days, rats were sacrificed. Adhesions were examined macroscopically, and degree of adhesions was scored. A part of horn was excised, and superoxide dismutase (SOD) and glutathione peroxidase activities as well as malondialdehyde levels were evaluated, and histological score was calculated.

RESULTS

Total microscopic score of the NSEE group was significantly lower than the control group (p = .001) and was marginally significantly lower than the seprafilm group (p = .005). Collagen formation score was higher in the seprafilm group compared to the sham and NSEE groups (p < 0.001, p = .003, respectively). Apoptotic cells were lower in the NSEE group compared to the control group (p = .003) and also lower in the NSEE and NSVO groups compared to the seprafilm group (p = .001, p < .001, respectively). Only SOD activity was higher in the NSVO and seprafilm groups compared to the control group (p < .001).

CONCLUSION

NSEE form seems to have a possible effect in the prevention of PPAs. This may occur by its effect in decreasing collagen formation and by decreasing apoptosis in the injured tissues. NSVO form seems to induce SOD. Therefore, combined use of NSVO with seprafilm may increase the adhesion preventive effect of seprafilm.

Melatonin treatment results in regression of endometriotic lesions in an ooferectomized rat endometriosis model

OBJECTIVE

We aimed to determine the effects of melatonin treatment on endometrial implants in an oopherectomized rat endometriosis model.

MATERIAL AND METHODS

This study is a prospective, randomised, controlled experimental study. It was carried out at the Experimental Research Center of Yeditepe University (YUDETAM). Twenty-two, female, non-pregnant, nulligravid Spraque-Dawley albino rats were included in our study. Endometriosis was surgically induced in oopherectomized rats. Rats were randomised into two groups: control group and melatonin group. In the melatonin group, rats were treated with melatonin (20 mg/kg/day) for two weeks. After the operations were performed to assess the regression of the endometriotic lesions, melatonin treatment was stopped. At the end of the sixth week necropsies were performed to assess the rate of recurrence. The volume and histopathological scores of endometriotic foci were examined.

RESULTS

Volumes of the endometriotic lesions significantly decreased in the melatonin group. Also, when the melatonin group was analysed within itself, endometriotic lesion volumes decreased and histopathological scores increased significantly.

CONCLUSION

Melatonin causes regression of the endometriotic lesions in rats and improvement in their histopathological scores.

Medical ozone therapy decreases postoperative uterine adhesion formation in rats

PURPOSE

Various studies have been performed to find out novel treatment strategies to prevent postoperative adhesion formation. Ozone therapy (OT) is shown to reduce inflammation in several pathological conditions. Therefore, we aimed to evaluate the efficacy of OT in a rat model of experimental uterine adhesion (EUA).

METHODS

Thirty female Wistar rats (200-250 g) were divided into three groups: sham, EUA and EUA+OT. EUA and EUA+OT groups were subjected to the postoperative adhesion procedure by bipolar coagulation on the uterine horns and corresponding pelvic sidewall parietal peritoneum. EUA+OT group received 0.7 mg/kg daily single dose for 3 days of ozone/oxygen mixture intraperitoneally after adhesion induction. All animals were killed on the 7th day and uterine adhesions were scored. Uterine tissues and peritoneal washing fluid were harvested for all analyses.

RESULTS

Uterine malondialdehyde levels in the EUA group were significantly higher compared to the other groups. However, in the EUA group, uterine superoxide dismutase and glutathione peroxidase activities were lower than in other groups. Peritoneal fluid TNF-α levels were found to be significantly different for all groups (p < 0.001). Macroscopic total adhesion score was significantly higher in the EUA group compared to the other groups (p < 0.001). But, total score in the EUA+OT group was lower than in the EUA group (p = 0.006).

CONCLUSIONS

Medical OT prevents postoperative uterine adhesions by modulating TNF-α levels and oxidative/antioxidative status in an experimental uterine adhesion model.

Efficacy of melatonin and hyaluronate/carboxymethylcellulose membrane in preventing adhesion reformation following adhesiolysis in a rat uterine model

AIM

To evaluate the efficacy of hyaluronate/carboxymethylcellulose (HA/CMC) membrane and melatonin separately and in combination in reducing adhesion reformation following adhesiolysis of surgically induced adhesions in a rat uterine horn adhesion model.

METHODS

A randomized, prospective study was carried out in a university animal laboratory. Ninety-eight female Sprague-Dawley albino rats were operated on. Following infliction of standard lesions, all the animals underwent second operations after one week. In all the animals, there were dense and vascular adhesions only between the uterine horns. These adhesions were lysed. Following the completion of adhesiolysis, the animals were randomized before closure of the abdomen to one of four groups (melatonin, HA/CMC membrane, combination of melatonin and HA/CMC membrane, control group). Seven days after the second surgery, the third operations were carried out and adhesions were scored. The main outcome measures were type, tenacity, and extent of adhesions. Total adhesion scores were determined.

RESULTS

Adhesion scores in the melatonin and HA/CMC membrane groups were similar, and significantly lower than those in the control group (P < 0.001). Adhesion scores in the combination group were lower than those in the other three groups (P < 0.001).

CONCLUSION

Melatonin and HA/CMC membrane are both effective separately in preventing adhesion reformation following adhesiolysis, but in combination they are significantly more beneficial.

The effects of letrozole and melatonin on surgically induced endometriosis in a rat model: a preliminary study

OBJECTIVE

To determine the effects of letrozole and melatonin on surgically induced endometriosis in a rat endometriosis model.

DESIGN

Prospective, randomized, controlled, experimental study.

SETTING

Experimental Research Center of Yeditepe University (YUDETAM).

ANIMAL(S)

Thirty female, nonpregnant, nulligravid Wistar-Hannover albino rats.

INTERVENTION(S)

Surgical induction of endometriosis, administration of estrogen for 2 weeks, and laparotomy; administration of letrozole or melatonin for 2 weeks after induction of endometriosis, and laparotomy; administration of estrogen for 2 weeks and necropsy.

MAIN OUTCOME MEASURE(S)

The volume and histopathologic scores of endometriotic foci, and levels of superoxide dismutase, catalase, and malondialdehyde in the peritoneal fluid.

RESULT(S)

The mean volumes of the endometriotic foci were 99.6 +/- 18.8 mm(3), 21.5 +/- 7.4 mm(3), and 29.2 +/- 17.5 mm(3), and histopathologic scores were 2.5 +/- 0.7, 2.0 +/- 0.8, and 1.7 +/- 0.9 in the melatonin group at the end of the second, fourth, and sixth weeks, respectively. The mean volumes of the endometriotic foci were 75.9 +/- 26.3 mm(3), 29.8 +/- 14.7 mm(3), and 121.2 +/- 35.1 mm(3) and the histopathologic scores were 2.5 +/- 0.5, 2.2 +/- 0.8, and 2.7 +/- 0.4 in the letrozole group at the end of the second, fourth, and sixth weeks, respectively. In the melatonin group, peritoneal fluid superoxide dismutase and catalase levels increased statistically significantly.

CONCLUSION(S)

Melatonin caused more pronounced regression of endometriotic foci when compared with letrozole in a rat model. After the cessation of melatonin treatment, the recurrence rate was lower than that observed after the cessation of letrozole treatment.

A randomised controlled trial on melatonin and rosiglitazone for prevention of adhesion formation in a rat uterine horn model

PURPOSE

To investigate the effectiveness of melatonin and rosiglitazone in reducing postoperative adhesion formation in a rat uterine horn model.

METHODS

Thirty non-pregnant female Wistar albino rats, weighing 180-220 g, were used as a model for postoperative adhesion formation. The rats were randomised into three groups after seven standard lesions were inflicted in a 2-cm segment of each uterine horn and lower abdominal sidewall using bipolar cauterisation. The rats were treated with 10 mg/kg, intraperitoneal melatonin, and 1 mg/kg per day peroral rosiglitazone. No medication was given to the control group. As much as 20 uterine horns of 10 rats were evaluated in each group. Extent, severity, and degree of the adhesions to the uterine horns and, inflammation and fibrosis scores (histopathologically) were evaluated after 2 weeks of the treatment.

RESULTS

There was no mortality in the groups and all of the rats recovered without incident after operation. Rosiglitazone group had lower adhesion scores [median (min-max ranges)] regarding extent, severity, and degree of the adhesions [0 (0-3), 0 (0-3) and 0 (0-3), respectively], which were significantly different (P < 0.001, P < 0.05 and P < 0.01, respectively) from those of the controls [1 (0-3), 2 (0-2) and 2 (0-3), respectively]; however, there were no statistically significant differences between rosiglitazone versus melatonin groups [1 (0-4), 2 (0-3) and 1 (0-3), respectively] and melatonin versus control groups. Moreover, no significant differences were determined between groups regarding histopathologic findings.

CONCLUSION

Rosiglitazone, but not melatonin, is effective in prevention of adhesion formation in a rat uterine horn model.

The effect of resveratrol on prevention of the development of postoperative adhesions in a rat model

OBJECTIVE

Our aim was to investigate the anti-adhesion potential of resveratrol, a phytoestrogen naturally found in wine, in a rat uterine horn model.

METHODS

Lesions were created by laparotomy in the uterine horn of 70 rats, randomized before the operation into seven groups consisting of ten animals each: (1) control group, no adjuvant therapy; (2) intraperitoneal (IP) application of the resveratrol dilution vehicle, 10 mg/kg, before closing the laparotomy; (3) subcutaneous (SC) injection of dilution vehicle, 10 mg/kg, 30 min before the operation; (4) IP application of resveratrol, 10 mg/kg, before closing the laparotomy; (5) SC injection of resveratrol, 10 mg/kg, 30 min before the operation; (6) IP application of resveratrol, 10 mg/kg, before closing the laparotomy and continued SC daily for 5 days; and (7) SC injection of resveratrol, 10 mg/kg, 30 min before the operation and continued SC daily for 5 days. On the 14th postoperative day adhesion scores were determined. Levels of thiobarbituric acid-reactive substances and total antioxidant capacity (TAC) were also measured.

RESULTS

In animals treated with repeated SC resveratrol, adhesions were graded as significantly less severe than in the vehicle control group or the groups treated with resveratrol IP or IP plus SC. TAC of control group rats was significantly lower than that of animals treated with repeated SC resveratrol.

CONCLUSION

Repeated SC resveratrol significantly reduces adhesion formation.

Surgical adhesions: a timely update, a great challenge for the future

Damage to the peritoneum during abdominal surgery triggers a cascade of events aimed at repairing the damage. As part of this process, fibrin is deposited, which is the precursor to the formation of an adhesion between 2 damaged peritoneal surfaces. This can have a significant impact on morbidity and even mortality as well as large cost implications. Strategies to reduce adhesion formation include improving surgical techniques, optimizing laparoscopy conditions, using pharmacologic interventions targeted at the inflammatory response and/or fibrin deposition, and using agents that provide a physical barrier to adhesion formation. While these strategies have provided some success, none have yet proved totally successful in abolishing adhesions. Further research to ensure that adhesion prevention is optimal is therefore essential.