Injectable Asymmetric Adhesive-Antifouling Bifunctional Hydrogel for Peritoneal Adhesion Prevention

Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro-wound healing properties of existing anti-adhesion barriers, this work reports an injectable adhesive-antifouling bifunctional hydrogel (AAB-hydrogel). This AAB-hydrogel can be constructed by "two-step" injection. The tissue adhesive hydrogel based on gallic acid-modified chitosan and aldehyde-modified dextran is prepared as the bottom hydrogel (B-hydrogel) by Schiff base reaction. The aldehyde-modified zwitterionic dextran/carboxymethyl chitosan-based hydrogel is formed on the B-hydrogel surface as the antifouling top hydrogel (T-hydrogel). The AAB-hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti-adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion-cecum defect model. Results suggest that the AAB-hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB-hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB-hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.

Minimally invasive delivery of human umbilical cord-derived mesenchymal stem cells by an injectable hydrogel via Diels-Alder click reaction for the treatment of intrauterine adhesions

Intrauterine adhesions (IUA) are the most common cause of uterine infertility, and conventional treatments have not consistently achieved satisfactory pregnancy rates. Stem cell therapy shows promising potential for the clinical treatment of IUA. Although various advanced biomaterials have been designed for delivering stem cells to the uterine cavity, there remain significant challenges, particularly in devising therapeutic strategies for clinical application that minimize surgical incisions and conform to the intricate structure of uterine cavity. Herein, an injectable hydrogel loaded with human umbilical cord-derived mesenchymal stem cells (UCMSCs) was synthesized via the Diels-Alder click reaction for endometrial regeneration and fertility restoration, exhibiting suitable mechanical properties, good biocompatibility, and desirable degradation properties. Notably, this hydrogel permitted minimally invasive administration and integrated seamlessly with surrounding tissue. Our study revealed that the UCMSCs-laden injectable hydrogel enhanced cell proliferation, migration, angiogenesis, and exhibited anti-fibrotic effects in vitro. The implantation of this hydrogel significantly facilitated endometrium regeneration and restored fertility in a rat endometrial damage model. Mechanistically, in vivo results indicated that the UCMSCs-laden injectable hydrogel effectively promoted macrophage recruitment and facilitated M2 phenotype polarization. Collectively, this hydrogel demonstrated efficacy in regenerating damaged endometrium, leading to the restoration of fertility. Consequently, it holds promise as a potential therapeutic strategy for endometrial damage and fertility decline arising from intrauterine adhesions. STATEMENT OF SIGNIFICANCE: Severe endometrial traumas frequently lead to intrauterine adhesions and subsequent infertility. Stem cell therapy shows promising potential for the clinical treatment of IUA; however, challenges remain, including low delivery efficiency and compromised stem cell activity during the delivery process. In this study, we fabricated an injectable hydrogel loaded with UCMSCs via the Diels-Alder click reaction, which exhibited unique bioorthogonality. The in situ-gelling hydrogels could be introduced through a minimally invasive procedure and adapt to the intricate anatomy of the uterus. The UCMSCs-laden injectable hydrogel promoted endometrial regeneration and fertility restoration in a rat endometrial damage model, efficaciously augmenting macrophage recruitment and promoting their polarization to the M2 phenotype. The administration of UCMSCs-laden injectable hydrogel presents a promising therapeutic strategy for patients with severe intrauterine adhesion.

Investigation of anti-adhesion ability of 8-arm PEGNHS-modified porcine pericardium

In post-adhesion surgery, there is a clinical need for anti-adhesion membranes specifically designed for the liver, given the limited efficacy of current commercial products. To address this demand, we present a membrane suitable for liver surgery applications, fabricated through the modification of decellularized porcine pericardium with 20 KDa hexaglycerol octa (succinimidyloxyglutaryl) polyoxyethylene (8-arm PEGNHS). We also developed an optimized modification procedure to produce a high-performance anti-adhesion barrier. The modified membrane significantly inhibited fibroblast cell adherence while maintaining minimal levels of inflammation. By optimizing the modification ratio, we successfully controlled post-adhesion formation. Notably, the 8-arm PEG-modified pericardium with a molar ratio of 5 exhibited the ability to effectively prevent post-adhesion formation on the liver compared to both the control and Seprafilm®, with a low adhesion score of 0.5 out of 3.0. Histological analysis further confirmed its potential for easy separation. Furthermore, the membrane demonstrated regenerative capabilities, as evidenced by the proliferation of mesothelial cells on its surface, endowing anti-adhesion properties between the abdominal wall and liver. These findings highlight the membrane's potential as a reliable barrier for repeated liver resection procedures that require the removal of the membrane multiple times.

Novel therapeutic targets, including IGFBP3, of umbilical cord mesenchymal stem-cell-conditioned medium in intrauterine adhesion

Mesenchymal stem cells play important roles in repairing injured endometrium. However, the molecular targets and potential mechanism of the endometrial recipient cells for stem cell therapy in intrauterine adhesion (IUA) are poorly understood. In this study, umbilical cord mesenchymal stem-cell-conditioned medium (UCMSCs-CM) produced positive effects on a Transforming growth factor beta (TGF-β) induced IUA cell model. RNA-sequencing was performed on clinical IUA tissues, and the top 40 upregulated and top 20 downregulated mRNAs were selected and verified using high-throughput (HT) qPCR in both tissues and cell models. Based on a bioinformatic analysis of RNA-sequencing and HT-qPCR results, 11 mRNAs were uncovered to be the intervention targets of UCMSCs-CM on IUA endometrium cell models. Among them, IGFBP3 was striking as a key pathogenic gene and a potential diagnostic marker of IUA, which exhibited the area under the curve (AUC), sensitivity, specificity were 0.924, 93.1% and 80.6%, respectively in 60 endometrial tissues. The silencing of IGFBP3 exerted positive effects on the IUA cell model through partially upregulating MMP1 and KLF2. In conclusion, RNA-sequencing combined with HT qPCR based on clinical tissues and IUA cell models were used in IUA research and our results may provide some scientific ideas for the diagnosis and treatment of IUA.

Review of the Role of Metabolic Factors in Determining the Post-surgical Adhesion and its Therapeutic Implications, with a Focus on Extracellular Matrix and Oxidative Stress

The potential role of metabolic reprogramming in fibrogenesis has recently attracted interest. Extracellular matrix stiffness, inflammation, and subsequent oxidative stress are essential mediators in the causation of fibrosis. The prevention of post-surgical adhesion is a challenge in medicine. It is defined as a fibrotic disorder in which adhesive bands develop after abdominal or pelvic surgery. Despite many studies related to the pathogenesis of post-surgical adhesion (PSA), many unknowns exist. Therefore, evaluating different pathways may help characterize and identify the cause of fibrotic scar formation post-operation. Glucose and lipid metabolism are crucial metabolic pathways in the cell's energy production that may be targeted by hypoxia-induced factor alpha and profibrotic cytokines such as TGF-β to mediate fibrogenesis. Inhibition of upregulated metabolic pathways may be a viable strategy for ameliorating post-surgical adhesion. In this review, we have discussed the potential role of altered glucose and lipid metabolism in extracellular matrix (ECM) stiffness and oxidative stress as crucial mediators in fibrosis.

Influence of clinical zirconia surface treatments on microscopic characteristics and adhesion-proliferation behavior of human gingival fibroblasts

Zirconia is favored in dental implant applications due to its biocompatibility, mechanical properties, and esthetic appeal, particularly in its interaction with soft oral tissues such as the gingiva. To optimize zirconia for clinical use, surface treatments like sanding and polishing are essential. The aim of this study was to investigate the effects of clinical surface treatments on the microscopic characteristics of zirconia and the adhesion and proliferation of human gingival fibroblasts (HGFs). Scanning electron microscopy (SEM) and fluorescence microscopy were utilized to examine the microscopic morphology and roughness resulting from various clinical surface treatment procedures on zirconia and to assess their impact on the microscopic appearance and behavior of HGFs. The results showed that the application of surface treatment procedures, particularly polishing treatments, resulted in the formation of a regular shallow groove morphology and a significant reduction in roughness in zirconia. This was accompanied by improved cell proliferation, cell adhesion, and the expression of integrin β1 in HGFs. The results suggest that smoother zirconia surfaces promote better cell-material interactions, potentially improving the clinical success of dental implants. This research contributes to our understanding of the optimal surface roughness for soft tissue adhesion and the effect of different micro-morphologies on HGF attachment.

Multifunctional Oxidized Dextran-Metformin as a Tissue-Adhesive Hydrogel to Prevent Postoperative Peritoneal Adhesions in Patients with Metabolic Syndrome

Patients with metabolic syndrome (MetS) undergoing surgery are at high risk of developing peritoneal adhesions and other severe postoperative complications. However, the single shielding function and absence of physiological activity render conventional methods less useful in preventing adhesions in patients with MetS. To address this challenge, a convenient method is introduced for developing a novel tissue-adhesive hydrogel called oxidized dextran-metformin (ODE-ME) via Schiff base linkages. This injectable ODE-ME hydrogel exhibits excellent tissue-adhesive properties and various physiological functions, particularly enhanced antibacterial effects. Furthermore, in vivo experiments demonstrate that the hydrogel can effectively alleviate hyperglycemia, reduce excessive inflammation, and improve fibrinolytic activity in MetS mice, thereby preventing adhesions and promoting incisional healing. The hydrogel concurrently isolates injured tissues and lowers the blood glucose levels immediately after surgery in mice. Therefore, the ODE-ME hydrogel functions as a multifunctional barrier material and has potential for preventing postoperative peritoneal adhesions in patients with MetS in clinical settings.

An anti-inflammatory chondroitin sulfate-poly(lactic-co-glycolic acid) composite electrospinning membrane for postoperative abdominal adhesion prevention

Postoperative abdominal adhesion is a very common and serious complication, resulting in pain, intestinal obstruction and heavy economic burden. Post-injury inflammation that could activate the coagulation cascade and deposition of fibrin is a major cause of adhesion. Many physical barrier membranes are used to prevent abdominal adhesion, but their efficiency is limited due to the lack of anti-inflammatory activity. Here, an electrospinning membrane composed of poly(lactic-co-glycolic acid) (PLGA) providing support and mechanical strength and chondroitin sulfate (CS) conferring anti-inflammation activity is fabricated for preventing abdominal adhesion after injury. The PLGA/CS membrane shows a highly dense fiber network structure with improved hydrophilicity and good cytocompatibility. Importantly, the PLGA/CS membrane with a mass ratio of CS at 20% provides superior anti-adhesion efficiency over a native PLGA membrane and commercial poly(D, L-lactide) (PDLLA) film in abdominal adhesion trauma rat models. The mechanism is that the PLGA/CS membrane could alleviate the local inflammatory response as indicated by the promoted percentage of anti-inflammatory M2-type macrophages and decreased expression of pro-inflammatory factors, such as IL-1β, TNF-α and IL-6, resulting in the suppression of the coagulation system and the activation of the fibrinolytic system. Furthermore, the deposition of fibrin at the abdominal wall was inhibited, and the damaged abdominal tissue was repaired with the treatment of the PLGA/CS membrane. Collectively, the PLGA/CS electrospinning membrane is a promising drug-/cytokine-free anti-inflammatory barrier for post-surgery abdominal adhesion prevention and a bioactive composite for tissue regeneration.

Ferroptosis contributes to endometrial fibrosis in intrauterine adhesions

Intrauterine adhesions (IUA), characterized by endometrial fibrosis, is a challenging clinical issue in reproductive medicine. We previously demonstrated that epithelial-mesenchymal transition (EMT) and fibrosis of endometrial stromal cells (HESCs) played a vital role in the development of IUA, but the precise pathogenesis remains elucidated. Ferroptosis has now been recognized as a unique form of oxidative cell death, but whether it is involved in endometrial fibrosis remains unknown. In the present study, we performed an RNA-seq of the endometria from 4 severe IUA patients and 4 normal controls. Enrichment analysis and protein-protein interactions (PPIs) network analysis of differentially expressed genes (DEGs) were conducted. Immunohistochemistry was used to assess ferroptosis levels and cellular localization. The potential role of ferroptosis for IUA was investigated by in vitro and in vivo experiments. Here, we demonstrated that ferroptosis load is increased in IUA endometria. In vitro experiments showed that erastin-induced ferroptosis promoted EMT and fibrosis in endometrial epithelial cells (P < 0.05), but did not lead to pro-fibrotic differentiation in endometrial stromal cells (HESCs). Cell co-culture experiments showed that erastin-stimulated epithelial cell supernatants promoted fibrosis in HESCs (P < 0.05). In vivo experiments suggested that elevation of ferroptosis level in mice by erastin led to mild endometrial EMT and fibrosis. Meanwhile, the ferroptosis inhibitor Fer-1 significantly ameliorated endometrial fibrosis in a dual-injury IUA murine model. Overall, our findings revealed that ferroptosis may serve as a potential therapeutic target for endometrial fibrosis in IUA.

Polydopamine Nanoparticles-Based Photothermal Effect Against Adhesion Formation in a Rat Model of Achilles Tendon Laceration Repair

Background

Adhesion formation after tendon surgery is a major obstacle to repair of tendon ruptures, and there is still no effective clinical anti-adhesion method. Myofibroblasts expressing α-smooth muscle actin (α-SMA) play a crucial role in adhered fibrous tissue. Heat shock protein (Hsp) 72 can selectively prevent the activation of c-Jun N-terminal kinase (JNK), which mediates the conversion from fibroblasts to myofibroblasts. The purpose of this study was to investigate for the first time whether polydopamine nanoparticles (PDA NPs)-based photothermal effect would attenuate adhesion formation in a rat model of Achilles tendon laceration repair.

Materials and Methods

Forty-five adult male Sprague-Dawley rats were randomly assigned to the photothermal group, the control group and the PDA NPs group (n = 15 per group). The primary outcome measure was the adhesion scores at two weeks after surgery according to the grading of Tang et al. The secondary outcomes included the expressions of Hsp 72, JNK, phosphorylated JNK and α-SMA, which were measured by immunohistochemistry or Western blot.

Results

The average adhesion score was significantly lower in the photothermal group (4.25 ± 0.21) than that in the control group (5.29 ± 0.12) (p = 0.005) and the PDA NPs group (5.29 ± 0.20) (p = 0.005). Relative to the control group and PDA NPs group, Hsp 72 in the photothermal group was significantly increased whereas α-SMA and p-JNK was significantly decreased, but JNK was not found to be different across the three groups.

Conclusion

The photothermal effect produced by PDA NPs could reduce tendon adhesion formation in rats by inhibiting myocyte fibrosis, which may have potential in developing endogenous heating for postsurgical tissue adhesions.

Characterizing the inherent activity of urinary bladder matrix for adhesion, migration, and activation of fibroblasts as compared with collagen-based synthetic scaffold

The mechanism of action underlying the intriguing prominent bioactivity of urinary bladder matrix (UBM) for in situ tissue regeneration of soft tissue defects remains to be elucidated. It is speculated that the activity of UBM for cell adhesion, migration, and activation is inherent. The bioactivity of UBM for in situ tissue regeneration and its relation with the structure and intact soluble components of UBM were investigated in comparison to a collagen-based scaffold, PELNAC (PEL). We isolated the soluble component of the two materials with urea buffer, and evaluated the respective effect of these soluble components on the in vitro adhesion and migration of L929 fibroblasts. The spatiotemporal pattern of endogenous-cell ingrowth into the scaffolds and cell activation were investigated using a model of murine subcutaneous implantation. UBM is more capable of promoting the adhesion, migration, and proliferation of fibroblasts than PEL in a serum-independent manner. In vivo, as compared with PEL, UBM exhibits significantly enhanced activity for fast endogenous cell ingrowth and produces a more prominent pro-regenerative and pro-remodeling microenvironment by inducing the expression of TGF-β1, VEGF, MMP-9, and murine type I collagen. Overall, our results suggest the prominent bioactivity of UBM for in situ tissue regeneration is inherent.

Efficacy of gelatin sponge in the prevention of post-surgical intra-abdominal adhesion in a rat model

Although different products have been developed to prevent post-surgical adhesion, their efficacy remains unsatisfactory. This study aimed to evaluate the efficacy of the gelatin sponge in the prevention of post-surgical intra-abdominal adhesions in a rat model. Rats were randomly divided into sham, adhesion, and gelatin groups. All rats, except the sham group, underwent cecal abrasion to establish an adhesion model. After celiotomy, a sterile gelatin sponge was applied intra-abdominal on the abraded cecum in the gelatin group. Rats were sacrificed on day 14 post-surgery and intra-abdominal adhesions were evaluated and scored. Adhesion tissues were evaluated by histological, histochemical, and immunohistochemical analysis. Intra-abdominal adhesions were recorded in all rats of the adhesion group. Intra-abdominal application of gelatin sponge significantly (P < 0.001) reduced intra-abdominal adhesions by 91% in the gelatin group relative to the adhesion group. The histological analysis revealed a marked decrease (P < 0.001) in the inflammatory score and neovascularization in the gelatin group. The histochemical analysis found that gelatin sponge administration reduced adhesion formation and thickness of adhesion tissue. Moreover, gelatin sponge significantly (P < 0.0001) increased MMP-9 expression and decreased macrophage marker expression in adhesive tissue. This study revealed that the application of gelatin sponge markedly reduced the post-surgical intra-abdominal adhesions and suggests new guidance for using gelatin sponge as an anti-adhesive substance in clinical practice.

Stem cell therapy in the treatment of organic and dysfunctional endometrial pathology

BACKGROUND

Intrauterine adhesions caused by postpartum curettage, spontaneous abortions, interrupted pregnancies, endometrial ablations, infections and inflammations, can lead to a loss of endometrial function, with consequent hypomenorrhea and infertility in women of reproductive age. In a non-negligible percentage of cases, the available surgical methods and hormone therapy, with sequential administration of estrogen and progesterone, are ineffective. In fact, severe damage to the basal layer of the endometrium causes the loss of endometrial cell precursors and leads to the failure of regeneration of the functional layer to which the endometrium is cyclically exposed. Today, many researchers are evaluating the use of stem cells of different origins as a potential therapy to restore endometrial function.

METHODS

Our interest has been focused on adipose-derived stromal/stem cells (ADSCs) obtained by collecting subcutaneous adipose tissue and subsequently treating it with the MilliGraft^® method. This procedure produces a cell suspension, the stromal vascular fraction (SVF), which includes ADSCs and soluble factors such as proteins and extracellular vesicles (exosomes). The SVF thus obtained was characterized in its cellular composition and its functional factors. Our clinical protocol for the future use of adipose tissue in endometrial regeneration in its different phases is presented.

RESULTS

The data obtained, even though they still require further support and implementation, show the regenerative properties of SVF obtained from adipose tissue using a mechanical method.

CONCLUSIONS

These findings can contribute to the development of cell therapies using stem cells of different derivations which are increasingly being utilized in the treatment of endometrial lesions from adherent or dysfunctional pathologies.

The association between visceral adiposity with systemic inflammation, oxidative stress, and risk of post-surgical adhesion

Abdominal and pelvic adhesions are common post-operative complications. Despite new medical technologies, these adhesions are appearing to be unavoidable and little is known about their causation; for example, why certain patients/or tissues are more prone to adhesions. There have been no clinical studies about increasing the risk adhesions in obese patients, but there is some evidence about the molecular mechanisms involving visceral fat (VF) that may lead to profibrotic conditions. VF is an endocrine/inflammatory organ which produces many biologically active molecules such as adipokines and inflammatory cytokines. Inflammatory conditions, oxidative stress, and the expression some fibrotic molecules in the VF may induce pathological conditions in the abdominal cavity that predispose to the formation of fibrotic bands.

An Injectable Peptide Hydrogel Constructed of Natural Antimicrobial Peptide J-1 and ADP Shows Anti-Infection, Hemostasis, and Antiadhesion Efficacy

Postoperative adhesion is a common complication of abdominal surgery, which always has many adverse effects in patients. At present, there is still a lack of effective treatment measures and materials to prevent adhesion in the clinics. Herein, we report the potential use of J-1-ADP hydrogel formed by natural antimicrobial peptide jelleine-1 (J-1) self-assembling in adenosine diphosphate (ADP) sodium solution to prevent postsurgery adhesion formation. J-1-ADP hydrogel was found to have good antimicrobial activity against the bacteria and fungi tested and can be used to prevent tissue infection, which was thought to be one of the incitements of adhesion. Due to ADP being a platelet-activating factor, J-1-ADP hydrogel showed significant hemostatic activity in vitro verified by whole blood coagulation, plasma coagulation, platelet activation, and platelet adhesion assays. Further, it showed potent hemostatic activity in a mouse liver hemorrhage model. Bleeding was believed to be a cause of the formation of postsurgery adhesion. J-1-ADP hydrogel had a significant antiadhesion effect in a rat side wall defect-cecum abrasion model. In addition, it had good biocompatibility and degradation properties. So the present study may provide an alternative strategy for designing antimicrobial peptide hydrogel material to prevent postoperative adhesion formation in the clinic.

Superhydrophilic PLGA-Graft-PVP/PC Nanofiber Membranes for the Prevention of Epidural Adhesion

Background

The frequent occurrence of failed back surgery syndrome (FBSS) seriously affects the quality of life of postoperative lumbar patients. Epidural adhesion is the major factor in FBSS.

Purpose

A safe and effective antiadhesion material is urgently needed.

Methods

A superhydrophilic PLGA-g-PVP/PC nanofiber membrane (NFm) was prepared by electrospinning. FTIR was performed to identify its successful synthesis. Scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and water contact angle measurement were performed. CCK-8 assays were performed in primary rabbit fibroblasts (PRFs) and RAW264.7 cells to explore the cytotoxicity of PLGA-g-PVP/PC NFm. Calcein-AM/PI staining was used to measure the adhesion status in PRFs. ELISA was performed to measure the concentrations of TNF-α and IL-10 in RAW264.7 cells. In addition, the anti-epidural adhesion efficacy of the PLGA-g-PVP/PC NFm was determined in a rabbit model of lumbar laminectomy.

Results

The PLGA-g-PVP/PC NFm exhibited ultrastrong hydrophilicity and an appropriate degradation rate. Based on the results of the CCK-8 assays, PLGA-g-PVP/PC NFm had no cytotoxicity to PRFs and RAW264.7 cells. Calcein-AM/PI staining showed that PLGA-g-PVP/PC NFm could inhibit PRF adhesion. ELISAs showed that PLGA-g-PVP/PC NFm could attenuate lipopolysaccharide-induced macrophage activation. In vivo experiments further confirmed the favorable anti-epidural adhesion effect of PLGA-g-PVP/PC NFm and the lack of a strong inflammatory response.

Conclusion

In this study, PLGA-g-PVP/PC NFm was developed successfully to provide a safe and effective physical barrier for preventing epidural adhesion. PLGA-g-PVP/PC NFm provides a promising strategy for preventing postoperative adhesion and has potential for clinical translation.

Sterilized human skin graft with a dose of 25 kGy provides a privileged immune and collagen microenvironment in the adhesion of Nude mice wounds

This study aimed to report the effects of different doses of ionizing radiation on inflammatory and repair stage of human skin graft adherence in Nude mice wounds. Animals were divided into transplanted with irradiated human skin grafts (IHSG) at 25 and 50 kGy (IHSG 25 kGy; IHSG 50 kGy) and non-IHSG and euthanized on the 3rd, 7th and 21st days after the surgery, by gross and microscopic changes, immunostaining for human type I collagen (Col I) and mouse Col I and Col III and inflammatory cells. We found an effectiveness of human split-thickness graft adherence in mice transplanted with IHSG 25 kGy, as well decrease in dermo-epidermal necrosis and neutrophils, lower loss of skin thickness, epithelization and neo-vascularization. Day 21 post-transplantation with IHSG 25 kGy was observed a well-preserved human skin in the border of the graft, a prominent granulation tissue in an organization by proliferated fibroblasts, Col III deposition and increased B-cells and macrophages. A complete adherence of human skin graft occurred with IHSG 25 kGy. We suggest that the ionizing radiation at 25 kGy mediates inflammation and the repair stage of human skin graft adherence in murine model, thus emerging as a potential tool in healing cutaneous wounds.

E8002 Reduces Adhesion Formation and Improves Joint Mobility in a Rat Model of Knee Arthrofibrosis

Knee arthrofibrosis is a common complication of knee surgery, caused by excessive scar tissue, which results in functional disability. However, no curative treatment has been established. E8002 is an anti-adhesion material that contains L-ascorbic acid, an antioxidant. We aimed to evaluate the efficacy of E8002 for the prevention of knee arthrofibrosis in a rat model, comprising injury to the surface of the femur and quadriceps muscle 1 cm proximal to the patella. Sixteen male, 8-week-old Sprague Dawley rats were studied: in the Adhesion group, haemorrhagic injury was induced to the quadriceps and bone, and in the E8002 group, an adhesion-preventing film was implanted between the quadriceps and femur after injury. Six weeks following injury, the restriction of knee flexion owing to fibrotic scarring had not worsened in the E8002 group but had worsened in the Adhesion group. The area of fibrotic scarring was smaller in the E8002 group than in the Adhesion group (p < 0.05). In addition, the numbers of fibroblasts (p < 0.05) and myofibroblasts (p < 0.01) in the fibrotic scar were lower in the E8002 group. Thus, E8002 reduces myofibroblast proliferation and fibrotic scar formation and improves the range of motion of the joint in a model of knee injury.

Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling

Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, we show that contamination of gut microbes increases post-surgical adhesion formation. Using genetic lineage tracing we show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis. In conclusion, bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.

REVISED PREDICTIVE BIOMARKER FOR OCRIPLASMIN THERAPY IN VITREOMACULAR TRACTION DISORDERS

PURPOSE

To determine a statistically optimal limit of adhesion size in vitreomacular traction (VMT) syndrome for ocriplasmin treatment.

METHODS

In this retrospective, consecutive, interventional study, we included 106 patients treated with ocriplasmin injection because of VMT between July 2013 and January 2018. A univariate and multivariate risk analysis was performed with grouped factors and continuous factors. We used a receiver operating characteristic curve to measure the prognostic relevance of each continuous factor for therapy success and determined the statistically optimal cutoff value at which specificity and sensitivity are simultaneously maximized.

RESULTS

Among the grouped factors, only a phakic lens status showed a highly significant positive influence on the resolution of the VMT. For the continuous factors, only the adhesion diameter before injection was a good predictor of anatomical success. The statistically optimal threshold value for the adhesion size was calculated to be 480 µm. Eyes below this limit had a 6.84-fold better chance of VMT resolution compared with eyes with a larger adhesion diameter.

CONCLUSION

The threshold value of the VMT diameter for ocriplasmin therapy could be statistically defined as 480 µm and may thus be a new quantitative biomarker to predict treatment success.

Effect of time and temperature-dependent changes of IOL material properties on IOL: Lens capsule interactions

Posterior Capsule Opacification (PCO) is the most common complication associated with Intraocular Lens (IOL) implantation. Based on the assumption that the interactions between an IOL and the lens capsule (LC) may influence the extent of PCO formation, a new in vitro model was developed to quantify the adhesion force of an IOL to simulated LC using a custom-designed micro-force tester. Using this system, we examined the influence of temperature (room temperature vs. body temperature) and incubation time (0 vs. 24 h) on the adhesion force between IOLs and LCs. The results show that, in line with clinical observations of PCO incidence, the adhesion force increased at body temperature and with increase in incubation time in the following order, Acrylic foldable IOLs > Silicone IOLs > PMMA IOLs. By examining the changes of surface properties as a function of temperature and incubation time, we found that acrylic foldable IOLs showed the largest increase in their hydrophilicity and reported the lowest surface roughness in comparison to other IOL groups. Coincidentally, using a newly established macromolecular dye imaging system to simulate cell migration between IOLs and LC, we observed that the amount of macromolecular dye infiltration between IOLs and LCs was in the following order: PMMA IOLs > Silicone IOLs > Acrylic foldable IOLs. These results support a new potential mechanism that body temperature, incubation time, surface hydrophilicity and smoothness of IOLs greatly contribute to their tight binding to LCs and such tight binding may lead to reduced IOL: LC space, cell infiltration, and thus PCO formation.

Preventive effect of Rumex crispus L. on surgically induced intra-abdominal adhesion model in rats

BACKGROUND

Rumex crispus L. (Polygonaceae), known as "Labada" in Turkey, was reported to be used for the treatment of gynecological diseases such as postpartum complications and infertility in folk medicine. Earlier studies on R. crispus have shown that leaf, fruit and root extracts have anti-inflammatory and antioxidant activities and are used for the treatment of tumors in the uterus. The hypothesis of this study is that R. crispus may generate potential anti-adhesive activity against complex factors such as inflammation, oxidation and fibrosis.

OBJECTIVES

We aimed to investigate the potential anti-adhesive activity of aqueous methanol extracts of leaves, fruits and roots of R. crispus.

METHODS

Abdominal adhesion model was performed in 72 female Wistar Albino rats. In the first step of the experiment, the rats were divided into six groups namely, Sham, Control, Reference and Experimental Groups (consisting of three sub-groups in which R. crispus leaf, fruit and root extracts were applied at 100 mg/kg dose). The test samples were administered once to the peritoneal cavity and the rats were sacrificied at the end of the 14th day. Root extract showed prominent activity, therefore this extract was subjected to fractionation to obtain 3 fractions (30-60-100% methanol fractions) by using vacuum-liquid chromatography. In the second stage, animals were divided into 6 groups as Sham, Control, Reference and Experimental Groups (R30, R60, R100 at 100 mg/kg dose). Adhesion scoring, tissue total antioxidant and oxidant levels, histopathological and immunohistochemical (TNF-α, IL-6 and IL-8) analyzes were performed.

RESULTS AND CONCLUSION

Adhesion scores, inflammatory cytokines and inflammation cells decreased by the application of R. crispus root extract. The fractions also showed similar anti-inflammatory effects, but R60 was found to be more effective in prevention of intra-abdominal adhesions and uterine fibrosis. R60 fraction, possessing potential bioactivity, was investigated in terms of phenolic composition by HPLC.

Dynamic exacerbation in inflammation and oxidative stress during the formation of peritendinous adhesion resulted from acute tendon injury

BACKGROUND

Peritendinous adhesion is among the common complications after tendon injury. Numerous studies have been carried out to prevent its formation, including modifications of surgical procedures, postoperative cares, application of medicines, etc. This study dynamically monitored fluctuations of inflammation, state of oxidative stress, and histopathologic changes around injured tendon to provide theoretical basis for further exploration in mechanisms of peritendinous adhesion formation.

METHODS

Eighteen mature Sprague-Dawley male rats were randomly allocated into 6 equal groups. Compared with control and sham group, every rat's right hind Achilles tendon in experimental groups was cut and repaired by the modified Kessler technique. Besides control and sham group, samples of tendon margin and serum were collected at different time points after the surgery. Content of TNF-α, IL-1β, and TGF-β were assayed in harvested serum. Reactive oxygen species (ROS) were detected, expression levels of related genes (IL-1β, IL-6, SOD1, SOD2, COL1, HIF1A) were quantified by qPCR, and various histopathological evaluations were performed.

RESULTS

Indicators (TNF-α, IL-1β, TGF-β1, ROS) were noticed to have a similar trend of significant rising 24 h after the surgery except TGF-β which was rising 72 h later. So were the expression trends of IL-1β, IL-6, SOD1, SOD2, and COL1. HIF1A, inversely correlated with SOD2, showed the progressive relief of regional tissue hypoxia. Histological evaluation showed the same tendency that fibrosis and inflammation were getting serious 48 h later after the surgery.

CONCLUSIONS

Inflammation, oxidative stress in injured tendon resulted from acute trauma, would be getting intense in 24 h. Peritendinous adhesion emerges and aggravates after 48 h. Thus, prompt efficient measures are advised to be taken after the injury as soon as possible.

An in vitro system to investigate IOL: Lens capsule interaction

Posterior capsule opacification (PCO) is the most common complication associated with intraocular lens (IOL) implantation. Unfortunately, current in vitro models cannot be used to assess the potential of PCO due to their failure to simulate the posterior curvature of the lens capsule (LC) and IOL, a factor known to affect PCO pathogenesis in clinic. To overcome such a challenge, a new system to study IOL: LC interaction and potentially predict PCO was developed in this effort. It is believed that the interactions between an IOL and the lens capsule may influence the extent of PCO formation. Specifically, strong adhesion force between an IOL and the LC may impede lens epithelial cell migration and proliferation and thus reduce PCO formation. To assess the adhesion force between an IOL and LC, a new in vitro model was established with simulated LC and a custom-designed micro-force tester. A method to fabricate simulated LCs was developed by imprinting IOLs onto molten gelatin to create simulated three dimensional (3D) LCs with curvature resembling the bag-like structure that collapses on the IOL post implantation. By pushing the LC mold vertically downward, while measuring the change in position of the bending bar with respect to its start position, the adhesion force between the IOLs and LCs was measured. An in vitro system that can measure the adhesion force reproducibly between an IOL and LC with a resolution of ~1 μN was established in this study. During system optimization, the 10% high molecular weight gelatin produced the best LC with the highest IOL: LC adhesion force with all test lenses that were fabricated from acrylic foldable, polymethylmethacrylate (PMMA) and silicone materials. Test IOLs exerted different adhesion force with the 3D simulated LCs in the following sequence: acrylic foldable IOL > silicone IOL > PMMA IOL. These results are in good agreement with the clinical observations associated with PCO performance of IOLs made of the same materials. This novel in vitro system can provide valuable insight on the IOL: LC interplay and its relationship to clinical PCO outcomes.

Antiadhesion effect of the C17 glycerin ester of isoprenoid-type lipid forming a nonlamellar liquid crystal

Postoperative adhesion is a relevant clinical problem that causes a variety of clinical complications after abdominal surgery. The objective of this study is to develop a liquid-type antiadhesion agent and evaluate its efficacy in preventing tissue adhesion in a rat peritoneal adhesion model. The liquid-type agent was prepared by submicron-sized emulsification of C17 glycerin ester (C17GE), squalene, pluronic F127, ethanol, and water with a high-pressure homogenizer. The primary component was C17GE, which is an amphiphilic lipid of one isoprenoid-type hydrophobic chain and can form two phases of self-assembly nonlamellar liquid crystals. The C17GE agent consisted of nanoparticles with an internal inverted hexagonal phase when evaluated by small-angle X-ray scattering (SAXS) and cryo-transmission electron microscopy (cryo-TEM). Upon contact with the biological tissue, this agent formed a thin membrane with a bioadhesive property. After this agent was applied to a sidewall injury of rats, it showed a percentage average of adhesion significantly less than that obtained with the Seprafilm® antiadhesion membrane in a rat model. Additionally, the retention of the agent prolonged at the applied site in the peritoneal cavity of rats. In conclusion, the C17GE agent is promising as an antiadhesion material. STATEMENT OF SIGNIFICANCE: Postoperative adhesion remains a common adverse effect. Although various materials have been investigated, there are few products commercially available to prevent adhesion. For the sheet-type agent, it is inconvenient to be applied through small laparotomy, especially in laparoscopic surgery. Additionally, the liquid-type agent currently used requires a complicated procedure to spray at the targeted site. Our liquid-type antiadhesion agent can form liquid crystals and act as a thin membrane-like physical barrier between the peritoneum and tissues to prevent adhesion. Indeed, the antiadhesion agent used in our present study significantly prevents adhesion compared with the antiadhesion membrane most used clinically. Moreover, our agent is highly stable by itself and easy to use in laparoscopic surgery, thus leading to a promising new candidate as an antiadhesion material.

Cross-linked electrospun cartilage acellular matrix/poly(caprolactone-co-lactide-co-glycolide) nanofiber as an antiadhesive barrier

In this work, we chose cartilage acellular matrix (CAM) as a promising antiadhesive material because CAM effectively inhibits the formation of blood vessels, and we used electrospinning to prepare antiadhesive barriers. Additionally, we synthesized N-hydroxysuccinimide (NHS)-poly(caprolactone-co-lactide-co-glycolide)-NHS (MP) copolymers (to tune degradation) as a cross-linking agent for CAM. This is the first report on the development of electrospun cross-linked (Cx) CAM/MP (CA/P) nanofiber (NF) (Cx-CA/P-NF) with a tunable degradation period as an antiadhesive barrier. Compared with the CA/P-NF before cross-linking, the electrospun Cx-CA/P-NF after cross-linking showed different biodegradation. Cx-CA/P-NF significantly inhibited the in vitro attachment and proliferation of human umbilical vein endothelial cells (HUVECs), as confirmed by an MTT assay and scanning electron microscopy images. Cx-CA/P-NFs implanted between a surgically damaged peritoneal wall and cecum gradually degraded in 7 days; this process was monitored by NIR imaging. The in vivo evaluation of the anti-tissue adhesive effect of Cx-CA/P-NFs revealed little adhesion, few blood vessels, and negligible inflammation at 7 days determined by hematoxylin and eosin staining. ED1 staining of Cx-CA/P-NFs showed infiltration of few macrophages because of the inflammatory response to the Cx-CA/P-NF as compared with an untreated injury model. Additionally, Cx-CA/P-NFs significantly suppressed the formation of blood vessels between the peritoneal wall and cecum, according to CD31 staining. Overall, Cx-CA/P-NFs yielded little adhesion, infiltration by macrophages, or formation of blood vessels in a postoperative antiadhesion assay. Thus, it is reasonable to conclude that the Cx-CA/P-NF designed herein successfully works as an antiadhesive barrier with a tunable degradation period.

STATEMENT OF SIGNIFICANCE

The cartilage acellular matrix (CAM) can inhibit the formation of fibrous tissue bridges and blood vessels between the tissue at an injured site and the surrounding healthy tissues. However, CAM has not been rigorously investigated as an antiadhesive barrier. In this manuscript, the cross-linked CAM nanofiber (Cx-CA/P-NF) designed herein successfully works as an antiadhesive barrier. Cx-CA/P-NFs yielded little adhesion, infiltration by macrophages, or formation of blood vessels in a postoperative antiadhesion assay. Moreover, we demonstrated the suitable properties of Cx-CA/P-NF such as easy cross-linking by maintaining the antiadhesive properties, controllable biodegradation, and in vivo antiadhesive effect of Cx-CA/P-NF.

A postoperative anti-adhesion barrier based on photoinduced imine-crosslinking hydrogel with tissue-adhesive ability

Postoperative adhesion is a serious complication that can further lead to morbidity and/or mortality. Polymer anti-adhesion barrier material provides an effective precaution to reduce the probability of postoperative adhesion. Clinical application requires these materials to be easily handled, biocompatible, biodegradable, and most importantly tissue adherent to provide target sites with reliable isolation. However, currently there is nearly no polymer barrier material that can fully satisfy these requirements. In this study, based on the photoinduced imine-crosslinking (PIC) reaction, we had developed a photo-crosslinking hydrogel (CNG hydrogel) that composed of o-nitrobenzyl alcohol (NB) modified carboxymethyl cellulose (CMC-NB) and glycol chitosan (GC) as an anti-adhesion barrier material. Under light irradiation, CMC-NB generated aldehyde groups which subsequently reacted with amino groups distributed on GC or tissue surface to form a hydrogel barrier that covalently attached to tissue surface. Rheological analysis demonstrated that CNG hydrogel (30mg/mL polymer content) could be formed in 30s upon light irradiation. Tissue adhesive tests showed that the tissue adhesive strength of CNG hydrogel (30mg/mL) was about 8.32kPa-24.65kPa which increased with increasing CMC-NB content in CNG hydrogel. Toxicity evaluation by L929 cells demonstrated that CNG hydrogel was cytocompatible. Furthermore, sidewall defect-cecum abrasion model of rat was employed to evaluate the postoperative anti-adhesion efficacy of CNG hydrogel. And a significantly reduction of tissue adhesion (20% samples with low score adhesion) was found in CNG hydrogel treated group, compared with control group (100% samples with high score adhesion). In addition, CNG hydrogel could be degraded in nearly 14days and showed no side effect on wound healing. These findings indicated that CNG hydrogel can effectively expanded the clinical treatments of postoperative tissue adhesion.

STATEMENT OF SIGNIFICANCE

In this study, a tissue adhesive photo-crosslinking hydrogel (CNG) was developed based on photo-induced imine crosslinking reaction (PIC) for postoperative anti-adhesion. CNG hydrogel showed the features of easy and convenient operation, fast and controllable gelation, suitable gel strength, good biocompatibility, and most importantly strong tissue adhesiveness. Therefore, it shows very high performance to prevent postoperative tissue adhesion. Overall, our study provides a more suitable hydrogel barrier material that can overcome the shortcomings of current barriers for clinical postoperative anti-adhesion.

Biodegradable and injectable thermoreversible xyloglucan based hydrogel for prevention of postoperative adhesion

Peritoneal adhesion is very common after abdominal and pelvic surgery, which leads to a variety of severe complications. Although numerous pharmacological treatments and barrier-based devices have been investigated to minimize or prevent postoperative adhesion, the clinical efficacy is not very encouraging. In this work, a biodegradable and thermoreversible galactose modified xyloglucan (mXG) hydrogel was developed and the efficacy of mXG hydrogel in preventing postoperative peritoneal adhesion was investigated. The 4% (w/v) mXG solution was a free flowing sol at low temperature, but could rapidly convert into a physical hydrogel at body temperature without any extra additives or chemical reactions. In vitro cell tests showed that mXG hydrogel was non-toxic and could effectively resist the adhesion of fibroblasts. Moreover, in vitro and in vivo degradation experiments exhibited that mXG hydrogel was degradable and biocompatible. Finally, the rat model of sidewall defect-cecum abrasion was employed to evaluate the anti-adhesion efficacy of the mXG hydrogel. The results demonstrated that mXG hydrogel could effectively prevent postoperative peritoneal adhesion without side effects. The combination of suitable gel temperature, appropriate biodegradation period, and excellent postoperative anti-adhesion efficacy make mXG hydrogel a promising candidate for the prevention of postsurgical peritoneal adhesion.

STATEMENT OF SIGNIFICANCE

Despite numerous drugs or barrier-based devices have been developed to prevent postoperative adhesion, few solutions have proven to be uniformly effective in subsequent clinical trials. In the present study, we developed a biodegradable and thermoreversible galactose modified xyloglucan (mXG) hydrogel by green enzymatic reaction without using any organic reagents. The developed physical mXG hydrogel not only showed excellent injectability, appropriate gelation time and temperature, but also exhibited excellent biocompatibility and biodegradability both in vitro and in vivo. In addition, mXG hydrogel was easy to handle and could effectively prevent postoperative adhesion without side effects in a rat model of sidewall defect-bowel abrasion. Our study provide a safe and effective postoperative anti-adhesion material which may have potential applications in clinical practice.

Aqueous outflow facility after phacoemulsification with or without goniosynechialysis in primary angle closure: a randomised controlled study

BACKGROUND

Goniosynechialysis (GSL) to remove peripheral anterior synechiae (PAS) alongside standard cataract surgery has potential theoretical advantages, Published randomised trials, however, have not shown conclusive functional benefits and aqueous outflow changes following GSL are unknown. This study aimed to compare electronic Shiøtz tonographic aqueous outflow facility (TOF) following phacoemulsification with or without GSL in patients with primary angle closure (PAC) and PAC glaucoma. Secondary outcomes were changes in intraocular pressure (IOP) and use of glaucoma medications.

METHODS

Prospective randomised pilot study of 26 patients on glaucoma medication, with ≥90° PAS and significant lens opacity. Patients were randomised 1:1 to receive phacoemulsification with intraocular lens (IOL) implantation only (phaco) or phacoemulsification with IOL plus GSL (phaco-GSL).

RESULTS

Fourteen patients were randomised to phaco-GSL and 12 to phaco alone. TOF increased with phaco-GSL from 0.099±0.07 μL/min/mm Hg to 0.194±0.07, μL/min/mm Hg, p=0.0006, while the phaco group showed no significant change. IOP reduced in both groups, but reduced significantly more following phaco-GSL (46.0%) compared with phaco alone (27.6%, p=0.04). Medication use and extent of PAS only reduced with phaco-GSL, from 0.923±0.86 to 0.384±0.18 medications, p=0.0279, and from 249.2±83.4 to 110.8±53.9° PAS, 6 months postoperatively. No serious adverse events occurred in either group.

CONCLUSIONS

Eyes randomised to both surgical groups had similar and good outcomes at 6 months in this pilot study. However, only eyes undergoing GSL combined with standard phacoemulsification had significantly increased TOF, reduced glaucoma medication dependence and PAS postoperatively. GSL should therefore be considered in such patients.

TRIAL REGISTRATION NUMBER

NCT00719290, Results.

The Overexpression of TGF-β and CCN2 in Intrauterine Adhesions Involves the NF-κB Signaling Pathway

Intrauterine adhesions (IUA) are a significant cause of menstrual disturbance and infertility, but their pathogenesis still remains unclear. Here, we investigated the expression of TGF-β and CCN2 in IUA endometrial tissue by immunohistochemistry, western blotting and qRT-PCR assays, and found the expression of TGF-β and CCN2 in the endometrial tissue of IUA was significantly increased compared to normal endometrium and uterine septum (P<0.01), suggesting that TGF-β and CCN2 may play an important role in the formation of IUA. Moreover, the activity of the NF-κB signaling pathway in endometrial tissue of IUA was also significantly enhanced compared to normal endometrial and uterine septum (P<0.01) and positively correlated with the expression of TGF-β and CCN2, which suggested that TGF-β and CCN2 expression may be involved in the NF-κB signaling pathway. Blocking the NF-κB signaling pathway using SN50 resulted in the reduced expression of TGF-β in RL95-2 cells, which confirmed the association of the NF-κB signaling pathway and TGF-β in endometrial cells. Additionally, the expression of TGF-β and CCN2 was associated with IUA recurrence, which provides a potential prognostic indictor for IUA. Together, these results demonstrated that TGF-β and CCN2 play an important role in IUA formation, whose mechanism was associated with the activation of the NF-κB signaling pathway.

Reduction of epidural scar adhesion by topical application of simvastatin after laminectomy in rats

OBJECTIVE

Epidural scar adhesion is one of the major causes of the failed back surgery syndrome after laminectomy. Recent studies have shown that simvastatin has potent anti-fibrotic and anti-inflammatory properties. This study evaluates the effect of the topical application of simvastatin on reducing epidural scar adhesion after laminectomy in rats.

MATERIALS AND METHODS

Thirty-six male Sprague-Dawley rats were randomly divided into three groups: control, chitosan and simvastatin group. After laminectomy was performed at L1 level, simvastatin and chitosan were applied to the laminectomy sites. The control group received no additional treatment. Four weeks later, the rats were killed and the epidural adhesion was evaluated by macroscopic assessment, hydroxyproline content analysis and histological analysis. The number of fibroblasts and the optical density of the collagen were also determined.

RESULTS

The results showed that simvastatin could reduce epidural scar adhesion in rats. Little epidural adhesions were seen in the laminectomy sites treated with simvastatin. The hydroxyproline content, the number of fibroblasts and the optical density of the collagen in the simvastatin group were significantly less than those of the chitosan and control group. However, dense epidural adhesion was found in control group.

CONCLUSIONS

Topical application of simvastatin could reduce epidural scar adhesion after laminectomy in rats. Further research is necessary to determine the optimal dosage and the safety of simvastatin.

[Impact of abdominal cavity open EHF irradiation on activity of adhesive process in peritonitis]

In experiment on 45 rats a purulent peritonitis was simulated. There was established, that on background of a standard therapy for peritonitis application of abdominal cavity open irradiation of extreme high frequency (EHF) have promoted rapid stabilization of the lipid metabolism indices and the blood coagulation system, the reduction of intensity of lipids peroxidal oxidation processes and severity of systemic inflammatory reaction. Under the influence of complex treatment the severity of adhesive process was reduced in 5.4 times, comparing with such in animals, to whom a standard treatment was conducted only. The revealed pathogenetic aspects of the adhesions formation witnesses the expediency to add EHF irradiation to complex therapy of peritonitis.

[Prognostication and prophylaxis of the adhesions recurrence postoperatively in patients suffering acute adhesive peritoneal disease complicated by ileus]

The results of treatment of 92 patients, suffering an acute ileus, were analyzed. After urgent operative interventions for an acute ileus the recurrence have occurred in 19.6% patients. To reduce the operative intervention traumaticity the preference was given to local viscerolysis conduction. For the adhesions occurrence prophylaxis a barrier medicines were used, what have promoted the reduction of contents of a connective tissue metabolites, excluding oxyprolin, concentration of which have exceeded such in a control, what have guaranteed the risk lowering for postoperative adhesions occurrence.

Prevention of experimental postoperative peritoneal adhesions through the intraperitoneal administration of tanshinone IIA

Postoperative adhesions develop after nearly every abdominal surgery. The formation of adhesions is associated with the inflammatory response, fibrinolytic system, and extracellular matrix deposition in response to injury. Tanshinone IIA is one of the major extracts obtained from Salvia miltiorrhiza, which has anti-inflammatory effects on many diseases. Postoperative adhesions were induced by injuring the parietal peritoneum and cecum in Wistar rats, followed by the administration of various dosages of tanshinone IIA. The adhesion scores for each group were collected seven days after the initial laparotomy. The activity of the tissue-type plasminogen activator in the peritoneal lavage fluid was measured. The messenger ribonucleic acid expression levels of the tissue-type plasminogen activator, plasminogen activator inhibitor-1, and cyclooxygenase-2 in the ischaemic tissues were measured by quantitative real-time polymerase chain reaction. The intraperitoneal administration of tanshinone IIA is effective for the prevention of the formation of postoperative adhesions in rats. Tanshinone IIA increased fibrinolytic activity in the peritoneal lavage fluid and tissue-type plasminogen activator messenger ribonucleic acid expression in ischaemic peritoneal tissues but decreased the plasminogen activator inhibitor and cyclooxygenase-2 messenger ribonucleic acid expression significantly. These results revealed that tanshinone IIA was a potent postoperative adhesion preventer by enhancing fibrinolytic activity and decreasing cyclooxygenase-2 activity.

[Role of phosphoinositide 3 kinase/protein kinase B signal pathway in monocyte-endothelial adhesion induced by serum of rats with electrical burn]

OBJECTIVE

To observe the change in phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signal pathway in monocytes as induced by serum of rats with electrical burn, and to explore the effects of PI3K/Akt pathway on monocyte-endothelial cell adhesion.

METHODS

Sixty-four SD rats of clean grade were inflicted with electrical burn for the collection of serum of rats with electrical burn; another group of twenty-four SD rats were used to obtain normal serum without treatment. (1) Human monocyte line THP-1 was routinely cultured. The THP-1 cells in logarithmic phase were divided into normal serum group (resuspended in RPMI 1640 medium with 20% normal rat serum) and burn serum group (resuspended with RPMI 1640 medium with 20% serum of rats with electrical burn) according to the random number table, with 6 wells in each group. Morphology of THP-1 cells in normal serum group was observed at post culture hour (PCH) 24, and that in burn serum group at PCH 3, 6, 24. The contents of TNF-α in culture supernatant were determined by double-antibody sandwich ELISA at the corresponding time point in each group. The state of Akt activation was determined by Western blotting at PCH 3, 6, 24. (2) Another portion of THP-1 cells were divided into 4 groups according to the random number table, with 6 wells in each group. Cells in normal serum group and burn serum group were given with the same culture condition as above; cells in normal serum+inhibitor group and burn serum+inhibitor group were cultured with the same culture conditions as in the former two groups correspondingly with addition of 100 nmol/L wortmannin in the nutrient solution. At PCH 3 and 6, THP-1 cells were added into the well with a monolayer of endothelial cell line EA.hy926 to observe the monocyte-endothelial cell adhesion. Data were processed with one-way analysis of variance and LSD- t test.

RESULTS

(1) In normal serum group, THP-1 cells showed growth in suspension, with uniform shape at PCH 24. In burn serum group, the cell shape became irregular though the membrane was complete at PCH 3; cellular size became irregular and cell membrane and cytoplasm were swollen at PCH 6; cell membrane was disrupted with death of cells at PCH 24. The contents of TNF-α in culture supernatant in normal serum group at PCH 24 and in burn serum group at PCH 3, 6, 24 were respectively (38.5 ± 1.4), (75.1 ± 1.5), (91.5 ± 1.8), (117.0 ± 1.4) pg/mL (F = 1 415.306, P < 0.01). The contents of TNF-α in culture supernatant in burn serum group at PCH 3, 6, 24 were all significantly higher than the content of TNF-α in normal serum group at PCH 24 (with t values respectively 29.614, 42.852, 63.485, P values below 0.01). The ratio values of phosphorylated Akt to Akt in burn serum group at PCH 3, 6, 24 were respectively 2.66, 3.69, 1.17 times of those in normal serum group at the corresponding time point. (2) In normal serum group, normal serum+inhibitor group, burn serum group, and burn serum+inhibitor group at PCH 3 and 6, the numbers of THP-1 cells adherent to endothelial cells were respectively (231 ± 45), (280 ± 47), (703 ± 169), (335 ± 85) per 100-time field; (219 ± 49), (235 ± 21), (562 ± 123), (226 ± 29) per 100-time field (with F values respectively 25.630 and 18.975, P values below 0.01). The number of THP-1 cells adhered to EA.hy926 cells was significantly more in burn serum group than in normal serum group at PCH 3 and 6 (with t values respectively 6.189 and 6.601, P values below 0.01). The number of THP-1 cells adherent to EA.hy926 cells was significantly fewer in burn serum+inhibitor group than in burn serum group at PCH 3 and 6 (with t values respectively 6.821 and 6.465, P values below 0.01).

CONCLUSIONS

The serum of rats suffering from electrical burn can induce the monocytes to secrete TNF-α, thus enhancing monocyte-endothelial cell adhesion, but it can be inhibited by blocking PI3K/Akt signal pathway.

[Expression of apoptosis markers in adhesions in the abdominal cavity under the experimental conditions]

BACKGROUND

Our aim was to study the expression of markers of caspase-dependent and caspase-independent apoptosis pathway activation in the process of repair in case of damage of the serous membrane of the abdominal cavity.

MATERIALS AND METHODS

On the experimental model of adhesions in the abdominal cavity (male rats Wistar, n = 40) in dynamics from 2 hours to 30 days after injury to the peritoneum studied marker expression pro-apoptosis (Bcl-x) and anti-apoptosis (Bcl-2), and PARP-1.

RESULTS

It was found that in the conditions of traumatic injury of the peritoneum apoptosis and anti-apoptosis occur in parallel. In the initial period of the anti-apoptosis mechanisms prevail, and in later periods dominated phenomena pro-apoptosis. PARP-1 activation indicates an increase in the frequency of DNA damage cells, and the duration of this process stimulates cell death by caspase-independent pathway. Together, these processes result in the elimination of a large number of cells, especially fibroblast of zone connective tissue formation in an aseptic area of inflammation in the peritoneal injury. We first established that in the case of peritoneal injury marker expression of anti-apoptosis in the damage zone has the character of the two-wave with maximum expression at 1-third day of the pathological process with repetitive peak on the 14th day.

CONCLUSION

Identifying key parts of apoptosis in the formation of adhesions in the abdominal cavity, which can be used for the development of drugs for the prevention of adhesions.

Influence of the carboxymethyl chitosan anti-adhesion solution on the TGF-β1 in a postoperative peritoneal adhesion rat

The aim of this paper was to investigate the effect of carboxymethyl chitosan anti-adhesion solution on prevention of postsurgical adhesion. Forty adult male Wistar rats were randomly divided into three groups: 0.9% normal saline solution (group A), hyaluronic acid gels (group B) and carboxymethyl chitosan anti-adhesion solution (group C). The animals were treated with normal saline, hyaluronic acid gels or carboxymethyl chitosan anti-adhesion solution at the time of surgery. After 2 or 3 weeks, the degree of adhesions and histological effects were determined. The adhesions in groups B and C were significantly decreased, and the levels of TGF-β1 and hydroxyproline in group C were significantly lower than that in group A (P < 0.05). The histopathology in group C showed fewer inflammatory cells and fibroblasts. Carboxymethyl chitosan anti-adhesion solution can effectively prevent postoperative adhesion which is a promising drug delivery system in the context of postsurgical anti-adhesion.

Molecular implication of ADAM-15 and -17 in intrauterine adhesions

OBJECTIVES

To investigate the regulation of the proteins ADAM-15 and ADAM-17 in intrauterine adhesions (IUA).

STUDY DESIGN

68 patients were found to have IUA in a study performed at our Department of Gynecology, and 18 control volunteer participants were recruited in the study. The patients with IUA were assigned to three groups according to the classification of March et al.: IUA-I (n=28), IUA-II (n=22), and IUA-III (n=18). All the volunteers were assigned to the control group (Con, n=18). The expression of ADAM-15 and ADAM-17 in the adhesive band tissue in patients and the endometrium in volunteers was detected by western blot, real-time PCR, and immunohistochemistry.

RESULTS

The expression of ADAM-15 and ADAM-17 was significantly upregulated in both protein level and transcript level in IUA patients compared to that in controls. ADAM-15 expression was significantly higher in IUA-III (4.59±0.15) compared to IUA-II (3.18±0.12) and IUA-I (2.11±0.17; P<0.01). ADAM-17 expression was also significantly higher in IUA-III (3.25±0.11) compared to IUA-II (2.21±0.15) and IUA-I (1.78±0.21; P<0.01). The transcript levels of ADAM-15 and ADAM-17 showed similar patterns, and were markedly higher in grade III IUA patients compared to grade II and grade I. The severity of IUA was positively correlated to the protein and transcript expression level of ADAM-15 and ADAM-17 in uterine tissue.

CONCLUSIONS

The development of IUA is associated with regulation of ADAM15 and ADAM-17, which may be potential biological markers for evaluating the severity of intrauterine adhesions.

[Effects of Fukang oral liquid on the prevention of intrauterine adhesion and expressions of TGF-beta1, PAI-1 and MMP-9 in endometrium of rats]

OBJECTIVE

To investigate the preventing effect of Fukang oral liquid (fuk) in intrauterine adhesions and its effects on the expression of TGFbeta-1, PAI-1 and MMP-9 in endometrium of rats with intrauterine adhesions.

METHODS

50 female wistar rats were divided into high, medium, low dose of Fukang oral liquid group (Hfuk, Mfuk, Lfuk), blank control group (Bcon), and model control group (Mcon) (n = 10 in each group). The rats in Hfuk, Mfuk and Lfuk groups were treated with intragastric administration of 4 mL, 2 mL and 1 mL Fukang Oral Liquid per day, while the rats in Mcon group and Bcon group received 2 mL physiological saline intragastric administration per day. All of rats were executed on 10th day and the sample of endometrium was harvested for the study of histology and morphology and the expression of TGFbeta-1, PAI-1 and MMP-9.

RESULTS

Under the light microscope, the organizational structure of the uterine cavity and uterine wall was clear in Bcon group, the uterine cavity disappeared in Mcon group, and the layers structure remained normal arrangement in three fuk treated groups. TGFbeta-1 and PAI-1 protein expressions in Hfuk, Mfuk, Lfuk groups were less than those in Mcon group (P < 0.001), but MMP-9 protein expressions were higher. (P < 0.001).

CONCLUSION

Fukang oral liquid show preventing effect on IUA, the mechanism may be related to its effects on the expressions of TGF-beta1, PAI-1, and MMP-9 in the endometrium.

[Research progress of mechanism and prevention of peritendinous adhesions]

OBJECTIVE

To review the research progress of mechanism and prevention of peritendinous adhesions. Methods Recent literature about peritendinous adhesions was reviewed, and the results from experiments about the mechanism and prevention of peritendinous adhesions were analyzed.

RESULTS

The molecular mechanism of peritendinous adhesions is related to overexpressions of transforming growth factor beta 1, early growth response protein 1, matrix metallopeptidase 9, and so on. The present methods of prevention of peritendinous adhesions include drugs, barrier, optimizing rehabilitation, gene therapy, and so on. These methods have achieved good results in experiments, but the clinical applications have not been confirmed yet.

CONCLUSION

It is necessary to pay more attention to the research of mechanism of peritendinous adhesions and methods of its prevention and subsequently to convert them into clinical applications, which is significant to the prevention of peritendinous adhesions in the future.

Peritoneal fibrinolytic activity and adhesiogenesis

INTRODUCTION

Postoperative adhesions after abdominal or pelvic surgery remain an important clinical problem causing infertility, pain and bowel obstruction. Their prevention and treatment remains poorly understood and inadequate. The formation of adhesions is caused by the organization of a fibrin matrix, an organization that takes place during the coagulation process when there is suppression of fibrinolysis.

METHODS

In this study peritoneal tissue and peritoneal fluid from two groups of patients were sampled and analysed. The first group comprised of 12 patients undergoing abdominal surgery for an acute abdomen during which known peritoneal factors of aggression (trauma, chemical, bacterial) were present which are known to increase the propensity for peritoneal adhesion formation. A second group consisting of 6 patients undergoing surgery in the absence of these peritoneal aggression factors acted as a reference control group. Each patient had peritoneal tissue sampled at the time of surgery and analysed for levels of gene expression of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1). Patients also had peritoneal drain fluid collected postoperatively and analysed for quantities of fibrin degradation products (FDPs) and fibrinogen.

RESULTS

The aim of this study was to evaluate the role of PAI-1 and tPA genes at peritoneal tissue level. Peritoneal tissue was obtained during surgery and the variation of expression of PAI-1 and tPA genes was quantified. The obtained results highlighted an increase of expression in PAI-1 gene and decrease of expression in tPA gene in patients with increased factors of peritoneal aggression compared to patients without, indicating a decreased fibrinolytic potential in patients with increased peritoneal adhesion propensity. Increased factors of peritoneal aggression also resulted in increased levels of FDPs and fibrinogen in peritoneal exudates.

Expression of VEGF-receptors in TMJ synovium of rabbits with experimentally induced internal derangement

Our aim was to evaluate the expression of vascular endothelial growth factor receptors (VEGFRs) in the synovium of the temporomandibular joints (TMJ) of rabbits with experimentally induced internal derangement. Internal derangement was experimentally induced in 52 rabbit TMJ, and established on the right side of TMJ while the left side was used as the control. Each joint and its control was evaluated by magnetic resonance imaging (MRI) and endoscopy. The synovial tissues on both sides were harvested after one, two, three, and four weeks. The expression of VEGFRs mRNA was investigated in the experimental joint and its control using real-time polymerase chain reaction (PCR). Internal derangement was successfully confirmed in 45 of the 52 of the experimental joints (87%) on the right side by MRI and endoscopy. In the first and fourth week, the VEGFR-2 mRNA expression was higher in the experimental joints than in the controls (P=0.008 and P=0.02). Meanwhile, the VEGFR-1 mRNA expression was up-regulated in the experimental group compared with the controls during the fourth week (P=0.02). However, we found no significant differences in VEGFR-3 mRNA expression in the two groups during the first and fourth weeks. During the second and third weeks, the mRNA expression of the three receptors did not differ significantly among the groups. Our data have shown increased expression of VEGFR-1 and VEGFR-2 mRNA in the synovium of rabbit TMJ with internal derangement, which indicates that VEGFR-1 and VEGFR-2 may have important roles in the processes of internal derangement and formation of adhesions.

[The role of neutrophils in the formation of peritoneal adhesions]

BACKGROUND

The use of antibiotics during peritonitis appears to decrease the formation of postoperative intra peritoneal adhesions and reduce their severity. The effect of this antibiotic is still controversial.

AIM

To study the relationship between the decrease postoperative adhesions induced by rifamycin, and the number of neutrophils and the number of intraperitoneal bacteria.

METHODS

This is an experimental prospective, randomized singleblind study performed on adult male rats. The product used for the peritoneal lavage was rifamycin s. The animals were randomized into three groups: Group S: intra peritoneal lavage with saline to 9%, R25 Group: intra peritoneal lavage with rifamycin at a dose of 25 mg / kg group and 12.5 R: intra peritoneal lavage with rifamycin at a dose of 12.5 mg / kg. Adhesions score was evaluated according to Zulkhé by the same operator.

RESULTS

The adhesion score was significantly lower between groups S and R12.5 (p = 0.000) and group S and group R25 (P = 0.01). However, the difference was not significant between the two groups R 25 and R12.5 compared to S group (p = 0.655). The number of bacteria between the time of caecal resection (before peritoneal lavage) and the time of death or sacrifice was significantly decreased significantly in the groups R25, comparing the group S (p = 0.003). However, there is no significant difference between groups S and R12, 5 (p = 0.106). The number of neutrophils between the time of cecal resection (before peritoneal lavage) and the time of death or sacrifice decreased significantly in the groups R25 and R12, 5 in comparison to the group S. Between the group R25 and the S group, the difference is significant (p = 0.037) as well between the group R12, 5 and S (p = 0.026). However, there is no significant difference between the two groups R 25 and R12, 5 (p = 0.712).

CONCLUSION

The action of rifamycin sodium on neutrophils seems to be independent of its antibacterial action. These findings deserve to be explored at the end to clarify the mechanism of neutropenia by intra peritoneal washing with rifamycin and the relationship between neutropenia and post-operative adhesions.

Nitric oxide modulates metalloproteinase-2, collagen deposition and adhesion rate after polypropylene mesh implantation in the intra-abdominal wall

Prosthetic meshes are commonly used to correct abdominal wall defects. However, the inflammatory reaction induced by these devices in the peritoneum is not completely understood. We hypothesized that nitric oxide (NO), produced by nitric oxide synthase 2 (NOS2) may modulate the response induced by mesh implants in the abdominal wall and, consequently, affect the outcome of the surgical procedure. Polypropylene meshes were implanted in the peritoneal side of the abdominal wall in wild-type and NOS2-deficient (NOS2(-/-)) mice. After 15 days tissues around the mesh implant were collected, and inflammatory markers (the cytokine interleukin 1β (IL-1β) and NO) and tissue remodeling (collagen and metalloproteinases (MMP) 2 and 9) were analyzed. The lack of NOS2-derived NO induced a higher incidence of visceral adhesions at the mesh implantation site compared with wild-type mice that underwent the same procedure (P<0.05). Additionally, higher levels of IL-1β were present in the mesh-implanted NOS2(-/-) animals compared with control and wild-type mice. Mesh implantation induced collagen I and III deposition, but in smaller amounts in NOS2(-/-) mice. MMP-9 activity after the surgical procedure was similarly increased in both groups. Conversely, MMP-2 activity was unchanged in mesh-implanted wild-type mice, but was significantly increased in NOS2(-/-) mice (P<0.01), due to decreased S-nitrosylation of the enzyme in these animals. We conclude that NOS2-derived NO is crucial for an adequate response to and integration of polypropylene mesh implants in the peritoneum. NO deficiency results in a prolonged inflammatory reaction to the mesh implant, and reduced collagen deposition may contribute to an increased incidence of visceral adhesions.

[The relationship between HalphaD-5 and HbetaD-2 in infertile women's fimbriae tubes with adhesions and atresias]

OBJECTIVE

To investigate the expression and relationship of human alpha defensin-5 (HalphaD-5) and human beta defensin-2 (HbetaD-2) in human fimbriae tubes with adhesions and atresias.

METHODS

The tissue samples were collected from 30 human fimbriae tubes with adhesions and atresias, and 30 cases without adhesions and atresias. The expression of HalphaD-5 and HbetaD-2 in fimbriae tube tissue were measured by immunohistochemical SP methods. Image pro-plus 6.0 software was used to test the average IOD value of positive staining. Differences of HalphaD-5 and HbetaD-2 expressions were analyzed by independent-samples T test. The relationship between HalphaD-5 and HbetaD-2 was analyzed by Pearson correlation.

RESULTS

We found that HalphaD-5 and HbetaD-2 mainly expressed in the epithelial cells which face to lumen, mostly in the cytochylema. Both two groups expressed HalphaD-5 and HbetaD-2, but the degrees were different. Compared with human fimbriae tubes without adhesions or atresias, the expressions of HalphaD-5 and HbetaD-2 increased significantly in adhesion cases (P(HalphaD--5) = 0.000, P(HbetaD--2) = 0.02). In the group without adhesion, there was a positive correlation between HalphaD-5 and HbetaD-2 (r = 0.404, P = 0.027), while in the adhesion group, there was no correlation between HalphaD-5 and HbetaD-2 (P = 0.089).

CONCLUSION

HalphaD-5 and HbetaD-2 may protect fimbriae tubes during the pathological process of microorganisms attack.

Synergistic effects of hyperbaric oxygen and granulocytecolony stimulating factor on postoperative adhesion formation in a rat cecal abrasion model

PURPOSE

We investigated the synergistic effect of hyperbaric oxygen (HBO) and granulocyte-colony stimulating factor (G-CSF) on adhesion formation in rats.

METHODS

40 adult male Sprague-Dawley rats (250-350 g) were divided into 4 groups. In group-1, no further management was undertaken. Group-2 received HBO therapy, group-3 was treated with 50 ug/kg subcutaneous G-CSF once daily for 7 days following laparatomy and cecal abrasion and group-4 was given both G-CSF and HBO therapies. On the 7th day, all rats were sacrificed and adhesions were scored. Tissue samples from adhesions and peritonea and cecum wall were examined both pathologically and biochemically for tissue hydroxyproline content.

RESULTS

No mortality occurred in study groups. When the groups were evaluated according to the adhesion numbers and grades, there was a statistically significant difference between the control and groups 3 and 4 (P < 0.001). There was no statistically significant difference between groups 1 and 2 (p > 0.05). HBO + G-CSF group was significantly different from control, HBO and G-CSF groups, regarding hydroxyproline contents (p = 0.005). Inflammation and fibrosis did not differ significantly among the groups (p = 0.248), (p = 0.213).

CONCLUSION

HBO treatment could not reduce the adhesion formation alone. Combined use of HBO and G-CSF, has a markedly preventive effect on postoperative adhesion formation (Tab. 1, Fig. 2, Ref. 57).

[The expression and significance of TGF-beta 1 and its receptors in infertile women's fimbriae tubes with adhesions and atresias]

OBJECTIVE

To profile the expression of transforming growth factor-beta1 (TGF-beta1) and its receptors (TGF-beta R1 and TGF-beta R2) in human fimbriae tubes to valuate the role of TGF-beta 1 signal system in adhesions and atresias formation of infertile women's fimbriae tubes.

METHODS

The expressions of TGF-beta 1 and its receptors (TGF-beta R1 and TGF-beta R2) in fimbriae tubes were measured by immunohistochemical SP methods in 30 human fimbriae tube with adhesions and 15 cases without adhesions. The average integrated optical density (IOD) value of positive staining was tested by Image pro-plus 6.0 software. The results were analyzed with independ-samples T test and Pearson correlation.

RESULTS

TGF-beta 1, TGF-beta R1 and TGF-beta R2 chiefly expressed in the epithelial cells, also expressed in the vascular endothelial cells and fibroblasts. Compared with human fimbriae tubes without adhesions or atresias, the expression of these three molecules all increased significantly in adhesion cases (P<0.05). In adhesion group, there was a positive correlation between TGF-beta 1 and TGF-beta R1, TGF-beta 1 and TGF-beta R2 (P<0.05), but no correlation between TGF-beta R1 and TGF-beta R2 (P<0.05), while there was no correlation among these three factors in control group.

CONCLUSION

TGF-beta 1 signal system may be an important ring-joint in adhesions formation of human fimbriae tube.

[New aspects of pathogenesis of adhesive process in the abdominal cavity]

Adhesive process in the abdominal cavity is the leading cause of morbidity and mortality in abdominal surgery. The clinical investigation included 126 children with acute adhesive intestinal obstruction. All patients were divided into two groups: polyenzyme and monoenzyme groups. In the polyenzyme group there was one case of intestinal obstruction. In the monoenzyme group there were 4 children with intestinal obstruction. The experiment included 70 adult rats divided in two equal groups: the main and control groups. The main group animals were given a polyenzyme preparation. The control group had a high incidence of cecal adhesions, which was significantly higher than the number of adhesions in the main group (Chi-square test = 23.1, df=2, p = 0.001). Proteolytic enzymes induce cells to express, de novo, the vascular endothelial growth factor, fibroblast growth factor and Laminin. As a consequence of these effects, activation of T-lymphocytes and macrophages mediating the inflammatory response will be down-regulated. It was found that the levels of VEGF, FGF and Laminin in the abdominal cavity, detected by immunohistochemistry, were different in the rats having high level and having no postoperative abdominal adhesion. The level of angiogenesis factors was also rapidly normalized by means of polyenzyme therapy.

The effects of intraperitoneal sildenafil administration on healing of left colonic anastomoses and intra-abdominal adhesion formation in the presence of intra-abdominal infection

PURPOSE

The objective of this pilot study was to establish an animal model for intra-abdominal infection and to examine the effect of sildenafil on anastomotic healing of the left colon and intra-abdominal adhesion formation.

METHODS

Fourteen Winstar rats underwent colonic transsection and primary anastomosis after performing intra-abdominal infection. Rats were divided into two groups: Group 1 (n = 7): intra-abdominal infection, resection, and anastomoses; Group 2 (n = 7): intra-abdominal infection, resection, anastomoses, and sildenafil. Anastomotic bursting pressures, hydroxyproline levels, histopathologic grading, and abdominal adhesions were accessed on the postoperative Day 7.

RESULTS

Anastomotic healing was found to be improved in terms of a bursting pressure (P = 0.02). Histopathological examination revealed an increase in angiogenesis (P = 0.007). Moreover, intra-abdominal adhesions were significantly less in rats given sildenafil (P = 0.03).

CONCLUSION

Sildenafil may improve anastomotic healing of the left colon and diminishes peritoneal adhesion formation in the presense of abdominal infection.