The study on the safety and efficacy of amnion graft for preventing the recurrence of moderate to severe intrauterine adhesions

The predictive value of serum IL-17A and IL-6 expression in postoperative recurrence in patients with intrauterine adhesion

BACKGROUND

The recurrence rate of intrauterine adhesions (IUA) was high. At present, there are few studies on the relationship between proinflammatory factors IL-17A and IL-6 and IUA. The expression of serum IL-17A and IL-6 in IUA patients and their predictive value for postoperative recurrence were retrospectively analyzed.

METHODS

A total of 90 IUA patients who underwent hysteroscopic adhesion lysis in our hospital from January 2020 to January 2023 were selected as the IUA group. Patients were divided into mild, moderate, and severe IUA groups. At the same time, 60 cases of secondary infertility patients with normal endometrium were selected as the control group. The clinical baseline characteristics and serum levels of IL-17A and IL-6 were compared between control group and IUA group. To analyze the correlation and predictive value of IL-17A and IL-6 expression levels with the recurrence rate of IUA patients.

RESULTS

The preoperative levels of IL-17A and IL-6 in the IUA group were significantly higher than those in the control group. The higher the levels of inflammatory factors IL-17A and IL-6, the deeper the degree of IUA. Multivariate analysis showed that pregnancy, curettage history, IL-17A, and IL-6 levels were risk factors for IUA recurrence. In addition, the specificity and area under the curve of combining baseline data with postoperative serum IL-17A and IL-6 for predicting IUA were higher than those predicted separately.

CONCLUSION

The expression levels of serum IL-17A and IL-6 can be used as a value index to evaluate postoperative recurrence in IUA patients.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Comparison of the efficacy of autologous platelet gel and medical chitosan in the prevention of recurrence of intrauterine adhesions after transcervical resection of adhesion: a prospective, randomized, controlled trial

PURPOSE

Intrauterine adhesion (IUAs) in women is a debatable topic and there is no clear consensus in its management and treatment strategies. Previous treatment measures have limitations which necessitates to consider effective measures for prevention of recurrence of IUAs. Hence, the aim of this study to explore the efficacy and safety of intrauterine infusion of autologous platelet gel (APG) and medical chitosan in preventing recurrence of IUAs in females after transcervical resection of adhesion (TCRA).

METHODS

A prospective, randomized controlled trial was conducted among 80 patients presented with moderate to severe IUAs. Patients were randomized into two groups, APG group (n = 40) and medical chitosan group (n = 40). All patients were injected with either APG or medical chitosan after TCRA.

RESULTS

The postoperative recurrence rate of adhesions in APG group was significantly lower than those in medical chitosan group (21% vs 49%). The median AFS score during the second-look hysteroscopy was significantly lower in APG group than in medical chitosan group (P = 0.008). The median AFS score reduction after TCRA surgery was significantly higher in APG group than in medical chitosan group (median, 95% CI 7.000, 6.0 to 8.3 vs. 6.000, 5.0 to 7.0, P = 0.004). Subgroup analysis of platelet concentration (1000 as cut-off value) into high- and low-dose subgroups reported no significant correlation existed between APG and baseline characteristics, recurrence rate and postoperative AFS reduction score except for previous intrauterine operation (P < 0.05).

CONCLUSION

Thus, after TCRA, intrauterine injections of APG provides better efficacy and safety compared with intrauterine injections of medical chitosan in preventing recurrence of intrauterine adhesions.

Biological properties and surgical applications of the human amniotic membrane

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.

Deep Grouping Analysis of the Altered Cervical Canal Microbiota in Intrauterine Adhesion Patients

To deeply analyze the alterations of cervical canal microbiota in intrauterine adhesion (IUA) patients and microbiota's relation to intrauterine adhesion (IUA) severity, we prospectively enrolled 23 consecutive patients diagnosed with mild-to-severe IUA and 8 women with infertility, 3 women with submucous myomas, or 8 women with endometrial polyps, but without IUA, as non_IUA subjects. For deep grouping analysis, these enrolled women were divided into six groups, two groups, and four groups respectively. Cervical mucus was drawn from the cervical canal of each participant. The bacterial composition was identified by 16S rDNA high-throughput sequencing. For analysis of six groups, mild IUA patients had similar cervical canal microbiota diversity and composition with submucous myomas patients. Compared with mild IUA participants, patients with moderate or severe IUA had a significantly lower diversity of bacteria and higher load of Firmicutes. For analysis of two groups, IUA patients had a significantly lower diversity of bacteria and higher load of Firmicutes than non_IUA subjects. KEGG pathway function analysis showed that metabolic pathways, biosynthesis of secondary metabolites, and microbial metabolism in diverse environments were mostly enriched for these cervical canal microbiota in all enrolled patients. The severity of IUA was associated with the altered abundance of phylum Firmicutes/Acinetobacteria or genus Lactobacillus/Gardnerella in the cervical canal. Higher bacterial load but less diversity in the cervical canal may be related with the severity of IUA. The function of these cervical canal microbiota were mostly involved in metabolic pathways.

Study on Risk Factors Related to Intrauterine Adhesion Based on Meta-Analysis

Objective. Intrauterine adhesion (IUA) is a severe complication that occurs following abortion. To evaluate the related risk factors of uterine cavity adhesion by meta-analysis. Methods. The research literature on the influencing factors of patients with intrauterine adhesions published from January 2010 to December 2020 in PubMed, EMBASE, Cochrane Library, web of science, CNKI, Wanfang Data, VIP, and CBM were retrieved by computer. Two evaluators independently screened the literature, extracted the data, and evaluated the treatment according to the inclusion and exclusion criteria and then analyzed it with revman5.3 software. Results. Finally, 12 literatures were included, with a total sample size of 2341 cases. The results of meta-analysis showed that pelvic inflammation ( $p=0.05$ ), negative pressure during uterine suction ( $p<0.0001$ ), and uterine suction time ( $p<0.00001$ ) were the risk factors for uterine cavity adhesion. The combined or and 95% CI of each factor were 2.05 (1.24, 3.38), 125.61 (67.35, 183.87), and 4.52 (4.21, 4.84), respectively. However, the number of pregnancies, the number of curettages, the average number of births, abortion, myomectomy, menstrual abnormalities, and infertility have little impact on the occurrence of intrauterine adhesions ( $p>0.05$ ). Conclusion. Pelvic inflammatory disease, negative pressure during uterine suction and uterine suction time are the risk factors leading to uterine cavity adhesion.

Bone marrow mesenchymal stem cells combined with estrogen synergistically promote endometrial regeneration and reverse EMT via Wnt/β-catenin signaling pathway

BACKGROUND

Intrauterine adhesion (IUA) is a clinical disease characterized by the uterine cavity occlusion caused by the damage of the endometrial basal layer. Bone marrow mesenchymal stem cells (BMSCs) transplantation have the potential to promote endometrial regeneration mainly through paracrine ability. Estrogen is an indispensable and important factor in the repair of endometrial damage, which has been reported as a promising and adjunctive therapeutic application for stem cell transplantation therapy. This study aims to investigate the synergistic effect of BMSCs and estrogen on improving the endometrial regeneration and restoring the endometrium morphology in a dual damage model of IUA in rabbits and the underlying molecular mechanisms.

METHODS

BMSCs were isolated and identified by adipogenic and osteogenic differentiation and flow cytometry assays. The rabbit IUA animal model was established by a dual damage method of mechanical curettage and lipopolysaccharide infection. Additionally, we investigated the therapeutic impact of both BMSCs and estrogen either separately or in combination in a rabbit model. The retention of PKH26-labeled BMSCs was observed by vivo fluorescence imaging.The number of endometrial glands and the degree of fibrosis were observed by H&E and Masson staining respectively. Western blotting, Immunohistochemistry and immunofluorescence staining were performed to detect biomarkers related to endometrial epithelium, endometrial fibrosis and EMT. Finally, the protein expression of core molecules of Wnt/β-catenin pathway was detected by Western blotting.

RESULTS

PKH26-labeled fluorescence results revealed that BMSCs appeared and located in the endometrial glands and extracellular matrix area when orthotopic transplanted into the uterine cavity. Histological assays showed that remarkably increasing the number of endometrial glands and decreasing the area of endometrial fibrosis in the BMSCs combined with estrogen treatment group. Moreover, downregulated expression of fibrosis markers (fibronectin, CollagenI, a-SMA) and interstitial markers (ZEB1, Vimentin, N-cadherin), as well as upregulated E-cadherin expression were found in the combined group. Further study of in vivo staining revealed that fluorescence intensity of CK7 was stronger in the combined group than that of direct BMSCs intrauterine transplantation, while vimentin showed the opposite results. Moreover, the protein levels of β-catenin, Axin2, C-myc, CycinE of Wnt/β-catenin signaling pathway increased in the BMSCs combined with estrogen group than in the other treatment groups.

CONCLUSION

BMSCs combined with estrogen can promote the differentiation of stem cells into endometrial epithelial cells to facilitate the regeneration of damaged endometrium. The potential mechanism of the synergistic effect may inhibit the occurrence of EMT by activating the Wnt/β-catenin signaling pathway.

The Top 100 Most Cited Articles on Intrauterine Adhesion: a Bibliometric Analysis

Bibliometric analysis is a statistical method that attempts to assess articles by their citations, analyzing their frequency and citation pattern, which subsequently gleans direction and guidance for future research. Over the past few years, articles focused on intrauterine adhesions have been published with increasing frequency. Nevertheless, little is known about the properties and qualities of this research, and no current analysis exists that has examined the progress in intrauterine adhesion research. Web of Science Core Collection, BIOSIS Citation Index, and MEDLINE database were searched to identify articles on intrauterine adhesion published from 1950 to October 2020. The 100 most cited articles were chosen to analyze citation count, citation density, authorship, theme, geographic distribution, time-related flux, level of evidence, and network analysis. An overwhelming majority of these 100 articles were published in the 2010s (35%). Citations per article ranged from 30 to 253. Chinese authors published the most papers in the top 100, followed by the USA, France, Israel, and Italy. The most salient study themes included operative hysteroscopy and adjunctive treatments for improving reproductive outcomes. The most common level of evidence was level II, and there was no statistical difference in the number of citations between the levels. The network analysis indicated that hysteroscopy, hysteroscopic adhesiolysis, infertility, and the reproductive outcome had a great degree of centrality in the 2000s and 2010s. In comparison, placental implantation had a great degree of centrality in the 2000s, and stem cell and fibrosis had a great degree of centrality in the 2010s. The value of IUA investigation has been gradually appreciated recently. Hysteroscopic adhesiolysis was continuously explored to achieve better reproductive outcome. Over time, the main focus of research has gradually shifted from complications to postoperative adjuvant treatment. Moreover, breakthrough progress is needed in underlying mechanism and early prevention of IUA.

Management of intrauterine adhesions using human amniotic mesenchymal stromal cells to promote endometrial regeneration and repair through Notch signalling

Intrauterine adhesions (IUAs) severely hamper women's reproductive functions. Human amniotic mesenchymal stromal cell (hAMSC) transplantation is effective in treating IUAs. Here, we examined the function of Notch signalling in IUA treatment with hAMSC transplantation. Forty-five Sprague-Dawley female rats were randomly divided into the sham operation, IUA, IUA + E2, IUA + hAMSCs and IUA + hAMSCs + E2 groups. After IUA induction in the rats, hAMSCs promoted endometrial regeneration and repair via differentiation into endometrial epithelial cells. In all groups, the expression of key proteins in Notch signalling was detected in the uterus by immunohistochemistry. The results indicated Notch signalling activation in the hAMSCs and hAMSCs + E2 groups. We could also induce hAMSC differentiation to generate endometrial epithelial cells in vitro. Furthermore, the inhibition of Notch signalling using the AdR-dnNotch1 vector suppressed hAMSC differentiation (assessed by epithelial and mesenchymal marker levels), whereas its activation using the AdR-Jagged1 vector increased differentiation. The above findings indicate Notch signalling mediates the differentiation of hAMSCs into endometrial epithelial cells, thus promoting endometrial regeneration and repair; Notch signalling could have an important function in IUA treatment.

A review: progress in preventing tissue adhesions from a biomaterial perspective

Postoperative adhesions (POA) are one of the main problems suffered by patients and are a common complaint. It is considered to be closely associated with the healing mechanism of damaged tissues. Tissue adhesions accompany other symptoms such as inflammation, pain, and even dyskinesia under certain conditions, compromising the patients' quality of life. On the other hand, common treatments involve high costs, re-surgery or long-term hospital stays. Therefore, alternative approaches need to be formulated so that aforementioned problems can be resolved. To this end, a review of recent advances in this context is imperative. In this review, we have highlighted the mechanism of adhesion formation, advances in common therapeutic approaches, and prospective treatments in preventing tissue adhesions. Based on the literature, it can be determined that the disadvantages of available commercial products in the treatment of tissue adhesion have led researchers to utilize alternative methods for designing anti-adhesive products with different structures such as electrospun fibrous mats, hydrogels, and nanospheres. These studies are on the fast track in producing optimal anti-adhesion materials. We hope that this article can attract attention by showing various mechanisms and solutions involved in adhesion problems and inspire the further development of anti-adhesion biomaterials.

Recent developments in bio-scaffold materials as delivery strategies for therapeutics for endometrium regeneration

Intrauterine adhesions (IUAs) refer to the repair disorder after endometrial injury and may lead to uterine infertility, recurrent miscarriage, abnormal menstrual bleeding, and other obstetric complications. It is a pressing public health issue among women of childbearing age. Presently, there are limited clinical treatments for IUA, and there is no sufficient evidence that these treatment modalities can effectively promote regeneration after severe endometrial injury or improve pregnancy outcome. The inhibitory pathological micro-environment is the main factor hindering the repair of endometrial damaged tissues. To address this, tissue engineering and regenerative medicine have been achieving promising developments. Particularly, biomaterials have been used to load stem cells or therapeutic factors or construct an in situ delivery system as a treatment strategy for endometrial injury repair. This article comprehensively discusses the characteristics of various bio-scaffold materials and their application as stem cell or therapeutic factor delivery systems constructed for uterine tissue regeneration.

Sustained delivery of 17β-estradiol by human amniotic extracellular matrix (HAECM) scaffold integrated with PLGA microspheres for endometrium regeneration

The endometrial injury usually results in intrauterine adhesions (IUAs). However, there is no effective treatment to promote the regeneration of the endometrium currently. The decellularized amnion membrane (AM) is a promising material in human tissue repair and regeneration due to its biocompatibility, biodegradability, as well as the preservation of abundant bioactive components. Here, an innovative drug-delivering system based on human amniotic extracellular matrix (HAECM) scaffolds were developed to facilitate endometrium regeneration. The 17β-estradiol (E2) loaded PLGA microspheres (E2-MS) were well dispersed in the scaffolds without altering their high porosity. E2 released from E2-MS-HAECM scaffolds in vitro showed a decreased initial burst release followed with a sustained release for 21 days, which coincided with the female menstrual cycle. Results of cell proliferation suggested E2-MS-HAECM scaffolds had good biocompatibility and provided more biologic guidance of endometrial cell proliferation except for mechanical supports. Additionally, the mRNA expression of growth factors in endometrial cells indicated that HAECM scaffolds could upregulate the expression of EGF and IGF-1 to achieve endometrium regeneration. Therefore, these advantages provide the drug-loaded bioactive scaffolds with new choices for the treatments of IUAs.