Barrier effect of Esoxx(®) on esophageal mucosal damage: experimental study on ex-vivo swine model

Advances in natural polysaccharide/protein-based bioadhesive formulations for the potential application in esophagus: A review

The esophagus is susceptible to various injuries or disorders, which can significantly impact quality of life and pose potentially life-threatening risks. The unique anatomical and physiological characteristics of the esophagus present challenges in achieving optimal bioavailability and efficacy during diagnosis and treatment. To address these challenges, polysaccharide- and protein-based bioadhesive formulations have been developed to adhere to esophageal tissue, thereby prolonging residence time and enhancing diagnostic accuracy and therapeutic outcomes. Natural polysaccharides and proteins have garnered attention in the medical field owing to their exceptional properties, including biocompatibility, bioavailability, biodegradability, and low toxicity. A substantial body of research has demonstrated the significant potential of polysaccharides and proteins in clinical applications for the esophagus. The objective of this review is to discuss the structural characteristics and biological activities of various polysaccharides, including chitosan, hyaluronic acid, alginate, cellulose, guar gum, gellan gum, and xanthan gum, as well as proteins such as gelatin and fibrin, and their utilization in esophageal bioadhesive formulations. The practical challenges and prospects associated with implementing polysaccharide and protein-based bioadhesives on the esophagus are also discussed.

The progress of hyaluronic acid's application in therapeutic delivery

Hyaluronic acid (HA) is a widely available, bio-compatible, polysaccharide with unique physical and chemical properties, which have inspired its application in many fields. Firstly, HA is a significant representative in wound healing, embryonic development, repair as well as regeneration. Secondly, HA exhibits pregnant meaning in cancer progression. Tumor cell proliferation, invasiveness, and motility can be modulated by the accumulation of HA in tumor stoma. Thirdly, HA is an actor in regulation processes during the angiogenesis. The level of HA, even low-molecular-weight HA, is considered to be a biomarker of tumor malignancy. Within this work, an intense overview of its application and the use of HA in drug delivery systems is given.HA plays a crucial role in many cases, such as cell signaling, morphogenesis, matrix organization, tissue regeneration, and pathobiology. Biocompatibility, mucoadhesivity, hygroscopicity, biodegradability, and viscoelasticity are to mention as physico-chemical properties of hyaluronan. This is why exogenous HA is investigated for drug delivery systems and exhibits a representative therapy of cancer, esthetic medicine, rhinology, arthrology, and cosmetics.In the end, the proof of concept presented by clinical trials is convincing to further investigate native HA as well as modified one for therapeutic delivery purposes.

Topical Protection of Esophageal Mucosa as a New Treatment of GERD

Among the various factors implicated in the pathogenesis of gastroesophageal reflux disease (GERD), visceral hypersensitivity and mucosal resistance have been recently re-evaluated in relation to the increasing phenomenon of proton pump inhibitor failure, particularly in patients with nonerosive reflux disease (NERD). Intensive research has allowed us to understand that noxious substances contained in the refluxate are able to interact with esophageal epithelium and to induce the elicitation of symptoms. The frequent evidence of microscopic esophagitis able to increase the permeability of the mucosa, the proximity of sensory afferent nerve fibers to the esophageal lumen favoring the higher sensitivity to noxious substances and the possible activation of inflammatory pathways interacting with sensory nerve endings are pathophysiological alterations confirming that mucosal resistance is impaired in GERD patients. Accordingly, the reinforcement of protective mechanisms of esophageal mucosa by topical therapies has become a novel treatment target. Alginate, the combination of hyaluronic acid+chondroitin sulphate and Poliprotect have been shown to adhere to esophageal mucosa and to have good protective properties. Several placebo-controlled clinical trials have shown that these compounds, given alone or as add-on therapy for short periods, enable to relieve symptoms and to improve the quality of life in NERD patients. Further studies are needed to confirm the above results and to find new mucosal protectants in order to improve the management of NERD patients.

Experimental drugs for erosive esophagitis: what is in the clinical development pipeline?

INTRODUCTION

Proton pump inhibitor (PPI) has revolutionized the treatment of erosive esophagitis (EE) in the past few decades. However, roughly 30-40% of the patients, especially those with severe EE (Los Angeles Grade C/D), remain poorly responsive to this medication. Novel drugs have been formulated and/or repurposed to address this problem.

AREAS COVERED

This review highlights novel drugs that have been investigated for use in EE, such as mucosal protectants, prokinetics, transient lower esophageal sphincter relaxation (TLESR) reducers, novel PPIs, and the new potassium-competitive acid blocker (PCAB). Studies have demonstrated that PCAB has promising results (efficacy and safety) compared to PPI for the healing of EE, especially in severe diseases.

EXPERT OPINION

PCAB has gained interest in recent years, with pharmacokinetics and pharmacodynamics properties surpassing PPI. Although recent data on PCABs, which comprised mainly of Vonoprazan, have shown promising results, more randomized controlled trials for other PCAB drugs are needed to elucidate and confirm the superiority of this drug class to PPI, the current first-line treatment of EE.

Ziverel for PPI-refractory reflux symptoms: efficacy and mechanisms of action in humans

OBJECTIVES

It is thought that esophageal hypersensitivity in combination with an impaired mucosal barrier function contributes to PPI-resistant reflux symptoms. Ziverel, a bioadhesive agent that coats the esophageal wall, was shown to have a positive effect on reflux symptoms. However, the mechanisms of action are unclear. We aimed to assess the effect of Ziverel on esophageal sensitivity to acid and mucosal barrier function.

METHODS

We performed a double-blind randomized placebo-controlled crossover trial in PPI-refractory patients with reflux symptoms. Patients were assigned (1:1) to 14 days of Ziverel followed by 14 days of placebo or opposite treatment order. The effect was evaluated using acid perfusion tests, an upper endoscopy with electrical tissue impedance spectroscopy (ETIS) and esophageal biopsies. The primary outcome was the esophageal sensitivity based on perfusion sensitivity score. Secondary outcomes included mucosal barrier function and reflux symptoms and correlations between the different outcomes.

RESULTS

Perfusion sensitivity score was not significantly different during treatment with Ziverel (106 (73-115)) and placebo (102 (67-110)) (p = 0.508) along with total RDQ score (2.6 (1.9-3.3) vs 2.8 (1.6-3.5) p = 0.456). ETIS showed comparable values during treatment with Ziverel (13514 (8846-19734)Ω·m) and placebo (13217 (9127-24942)Ω·m (p = 0.650)). Comparing Ziverel and placebo no difference was seen in transepithelial electrical resistance (TEER) 203 (163-267) Ω.cm2 vs 205 (176-240) Ω.cm2 (p = 0.445) and fluorescein flux 775 (17-6964) nmol/cm2/h vs 187 (4-12209) nmol/cm2/h (p = 0.638).

CONCLUSION

Ziverel did not show a benefit on acid sensitivity, reflux symptoms or esophageal mucosal integrity compared to placebo in PPI-refractory patients with reflux symptoms.Trial registration: Netherlands Trial Register number: NL7670.

Multicentre prospective study to evaluate effectiveness and safety of gel-forming and hyaluronic-acid containing chewable tablets as add-on treatment in patients with gastroesophageal reflux disease (GERD) symptoms and unsatisfying proton pump inhibitor therapy

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common disease which in the majority of patients is treated with proton pump inhibitors (PPI). However, up to 45% of the patients remain symptomatic on a standard dose of PPI. This study investigated the effectiveness and safety of an add-on therapy with the gel-forming chewable tablet Sobrade® in patients unsatisfied with PPI treatment. The bioadhesive gel covers the oesophagus and thereby protects the mucosa from reflux events.

METHODS

47 patients with symptomatic GERD despite PPI treatment participated in this study. The gel-forming tablets were taken up to four times daily after meals and prior to bedtime. Severity and frequency of GERD symptoms were evaluated during two onsite visits prior and following 14 days of treatment and used to calculate the GERD score of the Reflux Disease Questionnaire. Furthermore, patients recorded symptoms as well as onset and duration of symptoms relief daily in their electronic dairies. Effectiveness of treatment was analysed using non-parametric paired Wilcoxon test. In addition, anchor-based minimal important differences (MID) were assessed.

RESULTS

Treatment resulted in significant reduction of GERD symptoms. Severity and frequency of 8 of the 9 assessed symptoms improved significantly during the treatment phase whereby most pronounced improvement was observed for heartburn. In agreement, all three subscales of the GERD score improved significantly. MID results suggest that patients considered a mean improvement of symptoms > 30% of initial severity as beneficial. Self-assessments by patients revealed first significant improvements of symptoms like heartburn and regurgitation from day 5 of treatment onwards. 49% of patients reported relief of symptoms within 15 min which lasted on average for 3.5 h. During the study no treatment emergent adverse events were reported and in 98% of all cases tolerability of the product was rated as very good or good.

CONCLUSIONS

This study revealed a pronounced improvement of the symptoms after add-on treatment with the gel-forming medical device. The very good safety and tolerability profile indicate an advantageous risk-benefit ratio.

TRIAL REGISTRATION

This non-interventional study was prospectively positively evaluated by the responsible ethic-committees.

How safe are heartburn medications and who should use them?

INTRODUCTION

Heartburn is a frequent symptom occurring in daily clinical practice and is mainly associated with gastroesophageal reflux disease (GERD). However, it can be stimulated by various factors and diseases other than GERD can present with heartburn. Therefore, physicians must be very careful in distinguishing GERD from non-GERD conditions in their patients, particularly when heartburn is refractory to anti-reflux medications.

AREAS COVERED

The aim of this narrative review was to analyze the medical literature regarding the prevalence of heartburn and the various clinical disorders which can be present with this symptom. The type of medications usually adopted for treating heartburn and their grade of safety have been reviewed using an extensive computerized (Medline/PubMed) search with particular focus on the last 20 years.

EXPERT OPINION

Many drugs can be used for relieving heartburn in patients with GERD, although PPIs are the pharmacological agents with the greatest efficacy. However, it must be highlighted that many non-GERD conditions may present clinically with this symptom whose intensity does not differ between GERD and functional esophageal disorders, which represent about 50% of all patients with suspected GERD. It is very important to identify these functional conditions because their treatment differs completely from that of GERD.

Gastroesophageal reflux disease in children: What's new right now?

Gastroesophageal reflux (GER) in children is very common and refers to the involuntary passage of gastric contents into the esophagus. This is often physiological and managed conservatively. In contrast, GER disease (GERD) is a less common pathologic process causing troublesome symptoms, which may need medical management. Apart from abnormal transient relaxations of the lower esophageal sphincter, other factors that play a role in the pathogenesis of GERD include defects in esophageal mucosal defense, impaired esophageal and gastric motility and clearance, as well as anatomical defects of the lower esophageal reflux barrier such as hiatal hernia. The clinical manifestations of GERD in young children are varied and nonspecific prompting the necessity for careful diagnostic evaluation. Management should be targeted to the underlying aetiopathogenesis and to limit complications of GERD. The following review focuses on up-to-date information regarding of the pathogenesis, diagnostic evaluation and management of GERD in children.

Esophagoprotective therapy in patients with erosive esophagitis

Aim. To evaluate the advantages of using combined therapy of proton-pump inhibitors (PPIs) and esophagoprotector in comparison with basic therapy of PPIs for 4 weeks based on the results of changes in the endoscopic picture.To compare the effectiveness of 4-week PPI therapy and 4-week combination therapy with PPI and esophagoprotector Alfasoxx (sodium hyaluronate, chondroitin sulfate, poloxomer 407) in patients with erosive esophagitis (EE) of any degree according to the Los Angeles Endoscopic Classification. Materials and methods. 81 patients with EE AC according to the Los Angeles endoscopic classification (1994) was enrolled in the study on the basis of the clinic of Peter the Great, Mechnikov North-Western State Medical University. By computer randomization, patients were divided into the control group 40 patients (pantoprazole 40 mg 1 time per day) and the intervention group 41 patients (pantoprazole 40 mg 1 time per day + Alfasoxx 1 sachet qid). The therapy was carried out for 4 weeks. In all patients before and after therapy, the frequency and severity of the main symptoms of gastroesophageal reflux disease (GERD) were assessed, esophagogastroduodenoscopy was performed. Results. The advantage of combination therapy over standard PPI monotherapy in patients with EE was revealed. According to the results of the control endoscopy, healing of erosions of the esophageal mucosa was observed in 39 out of 41 (95.1%) patients in the intervention group and 32 out of 39 (82.1%) in the control group. The proportion of patients who showed an improvement in the endoscopic picture before and after treatment for 4 weeks by at least 1 level according to the Los Angeles classification was significantly higher in the comparison group 41 patients (100%), while in the control group 33 patients (85%); p0.009. After treatment, the combination therapy group had a lower incidence (p0.01) and severity of heartburn (p0.01). The same results are demonstrated by combination therapy regarding the symptom belching of air: in the study group after treatment, this symptom occurred less frequently (p=0.014), its severity was significantly less than in the control group (p0.01). There was a statistically significant decrease in the need for on-demand antacid therapy in the study group. Conclusion. In this study involving 81 patients with erosive GERD, the benefits of combination therapy were demonstrated. The addition of Alfasoxx medical device to PPI therapy increases the clinical and endoscopic efficacy of therapy. This positive effect is associated with the esophagoprotective properties of the drug, based on unique pharmacodynamic characteristics. Combination therapy for GERD is preferred in patients with EE. Studies have shown the expediency of using Alfasoxx in case of insufficient effectiveness of classical acid-suppressive therapy for GERD.

Pharmacologic treatment of GERD in adolescents: Is esophageal mucosal protection an option?

Background

Gastroesophageal reflux disease (GERD) is still a challenging and difficult to treat condition in children. Although acid suppression represents the mainstay of treatment in adolescents, it is not devoid of adverse events, especially in the long-term.

Objectives

In this investigation we explored a new therapeutic avenue in GERD, that is esophageal mucosal protection.

Design

To this end, we performed an investigator-initiated, retrospective study to evaluate the efficacy and safety of a short-term treatment with Esoxx™ medical device in 25 adolescents with GERD-related symptoms. This mucoadhesive formulation contains two natural mucopolysaccharides (sodium hyaluronate and chondroitin sulphate) and adheres to the esophageal mucosa, exerting a protective effect against refluxed gastric contents and allowing mucosal healing.

Methods

Heartburn, epigastric burning and post-prandial regurgitation were scored with a pain VAS scale and re-evaluated after 3-week treatment with Esoxx (one stick post-prandially, three times daily).

Results

All patients completed the treatment without adverse effects and with good tolerability and compliance. All the three major symptoms significantly (p<0.001) improved after treatment. No patient required additional investigation (i.e. upper Gastrointestinal endoscopy) or medication (i.e. antisecretory drugs).

Conclusion

The results of this pilot study suggest that esophageal mucosal protection is a promising therapeutic avenue for GERD also in children. Provided, these data be confirmed by a large, randomized clinical trial, this medical device can enter our therapeutic armamentarium against this challenging disease.

Protective Mechanisms of Liquid Formulations for Gastro-Oesophageal Reflux Disease in a Human Reconstructed Oesophageal Epithelium Model

Purpose

A novel experimental design based on a human-reconstructed oesophageal epithelium (HO2E) model has been applied to quantitively assess the properties of a set of liquid formulations, Device A (Gerdoff^® Protection), Device B (Esoxx^® One), and Device C (Marial^® gel) developed to form a temporary physical barrier on the oesophageal epithelium and modify epithelial permeability so to protect the oesophageal mucosa from refluxate components.

Methods

The formulations were applied to a prewetted HO2E model for 15 min. Then, a 0.5% caffeine solution was applied, and its penetration kinetics was assessed at 1 h and 2 h in acidic environments (pH= 3.3) to mirror exposure of the oesophageal mucosa to acidic reflux in GORD patients. Caffeine permeated into the basolateral compartment (evaluated by HPLC-UV) and Lucifer yellow (LY) permeability were quantified 15 min after application of the caffeine in acidic environments.

Results

At the 15 min timepoint, Device A reduced caffeine permeation by 77.2% and LY flux by 30.4% compared to the untreated control and with a faster mode of action than that of the other liquid formulations. Transepithelial caffeine flux was reduced, albeit with different timing and efficiency, by all three compounds up to the end of the 2 hour experiment. At 1 h, Device A reduced the caffeine flux by 79.2%; Device B, by 67.2%; and Device C, by 37%.

Conclusion

These results confirm the ability of the medical devices tested to interact with the oesophageal epithelium and create a temporary physical protective film for up to 2 hours after their application. The results underline differences in the mechanism of action of the three medical devices, with Device A performing faster than the other formulations. The overall results support the relevance of the reconstructed mucosal model to investigate oesophageal epithelium–product interactions and precisely differentiate liquid formulation performance.

Barrier effect and wound healing activity of the medical device REF-FTP78 in the treatment of gastroesophageal reflux disease

REF-FTP78 is a class IIb medical device present on the market with different trade names and developed for the treatment of gastroesophageal reflux disease (GERD). This medical device is based on polysaccharides from Aloe Barbadensis and fucoidans from brown seaweeds, such as Undaria pinnatifida and Fucus vesiculosus, and aims to exert a protective effect on the esophageal mucosa against the noxious components of refluxate. The present study reports on the efficacy of REF-FTP78 devoting a particular attention to the barrier effect and wound healing properties, combined with antioxidant and anti-inflammatory activities. Film-forming properties and barrier effect were investigated on in vitro reconstructed human esophageal epithelium, through TEER measurement and evaluation of caffeine and Lucifer yellow permeability, and in an ex vivo swine model of esophageal mucosa damage. Antioxidant and anti-inflammatory properties were evaluated in terms of scavenging activity towards DPPH, ABTS and NO radicals and a wound healing assay was carried out to study the influence of the product on cell migration. The obtained results highlighted a significant barrier effect, with a reduction in caffeine penetration equal to 65.3%, the ability to both repair and prevent the damage caused by an acid insult, confirmed by a good transepithelial resistance for the tissue treated with the tested item, and the capacity to promote wound healing. Furthermore, the tested product showed good antioxidant and anti-inflammatory properties in the performed radical scavenging assays. These findings support the use of REF-FTP78 in the treatment of GERD.

In Vitro Modelling of Barrier Impairment Associated with Gastro-Oesophageal Reflux Disease (GERD)

Purpose

A novel experimental model based on a 3D reconstructed human oesophageal epithelium model (HO2E) has been developed to investigate the structural and functional changes of the oesophageal epithelium following exposure to a solution of HCl 0.1 N (pH = 1.2) mirroring GERD microenvironment condition.

Methods

The barrier structure modification after the exposure to the acid solution on HO2E tissues was investigated immediately after damage induction and after 1 hour post incubation and compared to HO2E tissues exposed to phosphate buffered saline solution. Immunofluorescence (IF) was applied to quantify the expression and localization of barrier function proteins: Claudin-1 (CLDN-1), Claudin-4 (CLDN-4), Zonulin-1 (ZO-1), E-Cadherin and Mucin-1 (MUC1). Barrier functionality was measured by TEER.

Results

In the acidic microenvironment, TEER measurement has shown some limitations and results were not applicable, whereas the evaluation of protein localization and quantification provided clear and robust evidence of the damage which occurred to the epithelium barrier structure. CLDN-4 expression significantly decreased after exposure to acid. ZO-1 protein appeared upregulated immediately after exposure to HCl and was mainly localized in the cytoplasm and not on the cell membrane. This different localization was also observed for CLND-1. CLDN-1, MUC1 and, to a lower extent, ZO-1 expression increased during the post-incubation period.

Conclusion

The relevant tissue biomarkers identified, CLDN-1 and MUC1, can be used to monitor TJ structure and epithelial barrier recovery after acid-induced damage which, in our experimental conditions, were non-destructive and suitable for recovery studies. The established model can be useful to investigate the mechanism of action of formulations acting on this specific pathophysiological condition and/or designed to potentiate the physiological defense mechanisms of oesophageal mucosa.

Native Spider Silk-Based Antimicrobial Hydrogels for Biomedical Applications

Novel antimicrobial natural polymeric hybrid hydrogels based on hyaluronic acid (HA) and spider silk (Ss) were prepared using the chemical crosslinking method. The effects of the component ratios on the hydrogel characteristics were observed parallel to the primary physicochemical characterization of the hydrogels with scanning electron microscopic imaging, Fourier-transform infrared spectroscopy, and contact angle measurements, which confirmed the successful crosslinking, regular porous structure, exact composition, and hydrophilic properties of hyaluronic acid/spider silk-based hydrogels. Further characterizations of the hydrogels were performed with the swelling degree, enzymatic degradability, viscosity, conductivity, and shrinking ability tests. The hyaluronic acid/spider silk-based hydrogels do not show drastic cytotoxicity over human postnatal fibroblasts (HPF). Hydrogels show extraordinary antimicrobial ability on both gram-negative and gram-positive bacteria. These hydrogels could be an excellent alternative that aids in overcoming antimicrobial drug resistance, which is considered to be one of the major global problems in the biomedical industry. Hyaluronic acid/spider silk-based hydrogels are a promising material for collaborated antimicrobial and anti-inflammatory drug delivery systems for external use. The rheological properties of the hydrogels show shear-thinning properties, which suggest that the hydrogels could be applied in 3D printing, such as in the 3D printing of antimicrobial surgical meshes.

Pharmacological Management of Gastro-Esophageal Reflux Disease: An Update of the State-of-the-Art

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic disorder, whose knowledge remains limited and the management of these patients changes continuously. This review provides a summary of the most recent advancements in the pathogenesis of this disease and the new drugs introduced into the market to overcome some of the unmet needs of traditional therapies. Nowadays, the most fruitful diagnostic examinations are 24-hour impedance-pH monitoring, which allows us to separate true NERD from esophageal functional disorders and high-resolution manometry, which helps to exclude the existence of motility disorders sharing the same symptoms of GERD. Proton pump inhibitors (PPIs) remain the first-choice therapy in the treatment of GERD, but a consistent proportion of these patients continue to experience symptoms despite their intake. These cases pertain mainly to the subpopulation with non-erosive reflux disease (NERD) and represent very challenging clinical situations, because it is mandatory to understand the reasons for PPI failure. The management of these difficult patients requires necessarily to test them and avoid the use of empiric treatments that are often unsuccessful, costly and potentially dangerous. Recently, several new drugs have been used to increase the defensive properties of this mucosa with promising results in randomized clinical trials.

A novel ex vivo porcine model of acid-induced esophageal damage for preliminary functional evaluations of anti-gastroesophageal reflux disease medical devices

Aim

The aim of the study was to set up a porcine ex vivo model of acid-induced damage and to evaluate its performance by means of multichannel intraluminal impedance and pH (MII-pH) live recording, histology, and Evans blue (EB) permeability assay.

Materials and Methods

Thirteen esophagi, collected at a slaughterhouse, were ablated of their sphincters, pinned upright on a support, and placed in a thermostatic hood at 37°C with two infusion tubes and an MII-pH probe inserted in the top end. Three esophagi (histology controls) were only left in the hood for 3.5 h before sampling, while the remaining organs underwent the experimental protocol including saline infusion and recovery recording, and acid solution infusion and recovery recording.

Results

MII-pH analysis highlighted a significantly stronger decrease during acid infusion when compared to saline, but a better post-infusion recovery for saline solution. At the end of the protocol, MII was still statistically lower than baseline. The acid-damaged esophagi significantly absorbed more EB dye, and histology revealed strong mucosal exfoliation.

Conclusion

The proposed model of esophageal acid damage seems to be repeatable, reliable, and achievable using organs collected at the slaughterhouse. MII recording proved to have good sensitivity in detecting mucosal alterations also in ex vivo trials.

Barrier Effect of a New Topical Agent on Damaged Esophageal Mucosa: Experimental Study on an ex vivo Swine Model

PURPOSE

AL2106 is a new medical device based on a mixture of chondroitin sulphate in a xyloglucan and glycerol solution made to maximize its bioadhesive capability to the esophageal mucosa. The aim of the present study was twofold to evaluate the AL2106 protective effect on the esophageal mucosa when exposed to an acidic solution mimicking gastric reflux and to assess the resilience of this effect to saline washing.

MATERIALS AND METHODS

A porcine ex vivo model was used and the effects of the new medical device were compared to a sodium alginate suspension (SAS) already present on the market which was assumed as reference. Mucosal damage was induced in 19 porcine esophagi by perfusion with an acidic solution added with pepsin, and Evans blue dye (EBD) tissue uptake was used as an indicator of mucosal permeability. The EBD penetration, expressed as EBD µg/g of dry tissue, was assessed in specimens of untreated damaged mucosa and in specimens treated with AL2106 or SAS. The same evaluation was carried out after washing with normal saline.

RESULTS

Both topical agents tested significantly reduced the EBD uptake by more than 60% (AL2106 8.4±4.5, SAS 3.6±2.7 vs control 23.2±13.1, p<0.01). The saline washing did not cause any significant reduction in the protective effect of AL2106 (8.6±5.9), while it significantly reduced that of SAS (5.9±4.3, p<0.05).

CONCLUSION

The new AL2106 medical device showed a good barrier effect against a reflux-like damaging solution and preserved this effect after the mucosal washing test, thus suggesting its possible relevance for the treatment of gastroesophageal reflux disease.

Protective and regenerative effects of a novel medical device against esophageal mucosal damage using in vitro and ex vivo models

Gastroesophageal reflux disease (GERD) is a common digestive disorder that causes esophagitis and injuries to the esophageal mucosa. GERD symptoms are recurrent during pregnancy and their treatment is focused on lifestyle changes and nonprescription medicines. The aim of this study was to characterize the mechanism of action of a new patented medical device, an oral formulation containing hyaluronic acid, rice extract, and amino acids dispersed in a bioadhesive polymer matrix, by assessing its protective effects in in vitro and ex vivo models of esophageal mucosa damage. Acidic bile salts and pepsin cocktail (BSC) added to CP-A and COLO-680 N esophagus cells were used as an in vitro GERD model to evaluate the binding capacities, anti-inflammatory effects and reparative properties of the investigational product (IP) in comparison to a viscous control. Our results showed that the IP prevents cell permeability and tight junction dysfunction induced by BSC. Furthermore, the IP was also able to down-regulate IL-6 and IL-8 mRNA expression induced by BSC stimulation and to promote tissue repair and wound healing. The results were confirmed by ex vivo experiments in excised rat esophagi through the quantification of Evans Blue permeability assay. These experiments provided evidence that the IP is able to bind to the human esophagus cells, preventing the damage caused by gastroesophageal reflux, showing potential anti-irritative, soothing, and reparative properties.

Scorpio D, Scozzoli M, Bettini G, Forni M, Bacci ML. Preliminary Assessment of the Mucosal Toxicity of Tea Tree (Melaleuca alternifolia) and Rosemary (Rosmarinus officinalis) Essential Oils on Novel Porcine Uterus Models

Antimicrobial resistance, an ever-growing global crisis, is strongly linked to the swine production industry. In previous studies, Melaleucaalternifolia and Rosmarinusofficinalis essential oils have been evaluated for toxicity on porcine spermatozoa and for antimicrobial capabilities in artificial insemination doses, with the future perspective of their use as antibiotic alternatives. The aim of the present research was to develop and validate in vitro and ex vivo models of porcine uterine mucosa for the evaluation of mucosal toxicity of essential oils. The in vitro model assessed the toxicity of a wider range of concentrations of both essential oils (from 0.2 to 500 mg/mL) on sections of uterine tissue, while the ex vivo model was achieved by filling the uterine horns. The damage induced by the oils was assessed by Evans Blue (EB) permeability assay and histologically. The expression of ZO-1, a protein involved in the composition of tight junctions, was assessed through immunohistochemical and immunofluorescence analysis. The results showed that low concentrations (0.2–0.4 mg/mL) of both essential oils, already identified as non-spermicidal but still antimicrobial, did not alter the structure and permeability of the swine uterine mucosa. Overall, these findings strengthen the hypothesis of a safe use of essential oils in inseminating doses of boar to replace antibiotics.

Pathophysiology, diagnosis, and pharmacological treatment of gastro-esophageal reflux disease

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic, relapsing disorder, whose knowledge has increased in last years thanks to the advent of new sophisticated techniques, such as 24-h impedance-pH monitoring and high-resolution manometry, for the study of esophageal functions.

AREAS COVERED

This review provides an overview of our advancements in understanding the complex pathophysiology, improving the diagnosis and defining the modern pharmacological therapeutic approach to GERD.

EXPERT OPINION

The growing clinical application of impedance-pH testing has allowed us to know the diversity of patients with non-erosive reflux disease (NERD), who nowadays represent about 70% of the whole population with reflux symptoms. We have realized that NERD has to be considered as an umbrella term covering various subgroups with different pathophysiologies. The development of new impedance metrics, in particular mean nocturnal baseline impedance, seems to be promising in the improvement of the diagnostic process of this disease. There are no particularly innovative features in the pharmacological therapy of GERD, unless the interest toward drugs is able to increase the defense properties of esophageal mucosa and/or its protection. These compounds can be of help in combination with proton pump inhibitors in NERD patients with partial response to antisecretory drugs alone.

Novel Therapies for Gastroesophageal Reflux Disease: Beyond Proton Pump Inhibitors

PURPOSE OF REVIEW

Despite the many areas of unmet needs in gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) remain the cornerstone of medical therapy. However, since their introduction, the therapeutic limitations of PPIs in GERD management have been increasingly recognized.

RECENT FINDINGS

In this review we discuss the new medical, endoscopic, and surgical therapeutic modalities that have been developed over the last decade. They include the potassium-competitive acid blockers (P-CABs) which provide a rapid onset, prolonged, and profound acid suppression, mucosal protectants which promote the physiological protective barrier of the esophageal mucosa, new prokinetics and neuromodulators. There are growing numbers of novel therapeutic endoscopic techniques that are under investigation or were recently introduced into the market, further expanding our therapeutic armamentarium for GERD. The development of diverse therapeutic modalities for GERD, despite the availability of PPIs, suggests that there are many areas of unmet need in GERD that will continue and drive future exploration for novel therapies.

[Current advances in the treatment of gastroesophageal reflux disease: a focus on esophageal protection]

Gastroesophageal reflux disease (GERD) is characterized by high morbidity and a significant decrease in the quality of life of patients, and is a major risk factor for esophageal adenocarcinoma. Nowadays, antisecretory therapy with proton pump inhibitors (PPI) is the "gold standard" of conservative treatment of GERD, but in some cases this therapy is unsuccessful. According to various studies, the prevalence of refractory GERD can reach 30-40%. The latest scientific data in the field of genetics and pathophysiology of GERD demonstrate that a disruption of the barrier function of the esophageal mucosa and an increase of its permeability can be the leading causes of refractoriness. Thus, the optimal therapy for patients with GERD should not only suppress the secretion of hydrochloric acid, but also restore the barrier function of the mucous membrane, providing an esophagoprotective effect. To achieve these goals, Alfasoxx was developed, which consists of a mixture of low molecular weight hyaluronic acid and low molecular weight chondroitin sulfate dissolved in a bioadhesive carrier (poloxamer 407). The clinical efficacy of this product has been confirmed by three prospective, randomized, placebo - controlled trials. Alfasoxx has a healing and restorative effect towards the esophageal epithelium and due to high ability for bioadhesion provides long - term protection of the mucous membrane of the esophagus. Combination therapy for GERD with the use of PPI and an esophagoprotector offers new perspectives for the treatment of patients with GERD.

Successful outcomes of a new combined solution of hyaluronic acid, chondroitin sulfate and poloxamer 407 for submucosal injection: animal survival study

Background and study aims  Endoscopic resection requires use of submucosal injection. This study was conducted to assess efficacy and impact on early healing of hyaluronic acid combined with chondroitin sulfate and poloxamer 407 (Ziverel) when used as a solution for submucosal injection. Materials and methods  Prospective and comparative study of gastric endoscopic mucosal resection (EMR) with three groups of two Yorkshire pigs. Six submucosal cushions were created in each animal by injecting 2 mL of Ziverel (Group 1) or succinylated gelatin (SG) (Group 2), enabling 12 EMR in each group. Submucosal cushions were created with Ziverel in Group 3, without resection. Electrosurgery unit settings were the same in all cases. EMR defects and injection sites were marked with clips. The animals were sacrificed 7 days later. EMR specimen size and duration of procedure were recorded. EMR specimens and EMR scars and injection sites were evaluated by a blinded pathologist. Results  We successfully performed 24 EMR (15 en-bloc and 9 piecemeal, without differences between groups 1 and 2). Mean EMR specimen dimensions were significantly larger in Group 1 (median 19 mm, range 6 - 40 vs 16.6 mm, range 5‑25; P  = 0.019), without changing the electrocautery unit settings. Blinded histopathologist assessment of EMR specimens showed less fibrosis in the submucosa and a trend to fewer cautery artifacts with Ziverel and did not identify any significant differences in early healing of resection sites. Conclusion  The combination of Ziverel enables EMR and does not negatively affect early healing.

Cyclodextrin Polymer Preserves Sirolimus Activity and Local Persistence for Antifibrotic Delivery over the Time Course of Wound Healing

Fibrosis and dysphagic stricture of the esophagus is a major unaddressed problem often accompanying endoscopic removal of esophageal cancers and precancerous lesions. While weekly injections of antiproliferative agents show potential for improved healing, repeated injections are unlikely clinically and may alternatively be replaced by creating an esophageal drug delivery system. Affinity-based polymers have previously shown success for continuous delivery of small molecules for weeks to months. Herein, we explored the potential of an affinity-based microparticle to provide long-term release of an antiproliferative drug, sirolimus. In molecular docking simulations and surface plasmon resonance experiments, sirolimus was found to have suitable affinity for beta-cyclodextrin, while dextran, as a low affinity control, was validated. Polymerized beta-cyclodextrin microparticles exhibited 30 consecutive days of delivery of sirolimus during in vitro release studies. In total, the polymerized beta-cyclodextrin microparticles released 36.9 mg of sirolimus per milligram of polymer after one month of incubation in vitro. Taking daily drug release aliquots and applying them to PT-K75 porcine mucosal fibroblasts, we observed that cyclodextrin microparticle delivery preserved bioactivity of sirolimus inhibiting proliferation by 27-67% and migration of fibroblasts by 28-100% of buffer treated controls in vitro. Testing for esophageal injection site losses, no significant loss was incurred under simulated saliva flow for 10 min, and 16.7% of fluorescently labeled polymerized cyclodextrin microparticle signal was retained at 28 days after submucosal injection in esophageal tissue ex vivo versus only 4% of the initial amount remaining for free dye molecules injected alone. By combining affinity-based drug delivery for continuous long-term release with a microparticle platform that is injectable yet remains localized in tissue interstitium, this combination platform demonstrates promise for preventing esophageal fibrosis and stricture.

A hyaluronic acid- and chondroitin sulfate-based medical device improves gastritis pain, discomfort, and endoscopic features

Gastritis is an inflammation of the gastric mucosa. In this study, we investigated the efficacy of a medical device, Esoxx®, based on hyaluronic acid and chondroitin sulfate on gastritis-related upper abdominal pain/discomfort and endoscopic features. Fifty patients, affected by gastritis, were randomised to receive the medical device or placebo. The primary endpoint was the medical device efficacy on upper abdominal pain/discomfort associated with gastritis and measured by Visual Analogue Scale (VAS). The secondary endpoints were the efficacy of the medical device on gastritis-related mucosal erosions, blood oozing, and hyperemia (redness)/edema, as assessed by endoscopy, and the patients’ rating of their compliance with the treatments. A significant reduction in VAS pain was observed in the treatment group after a 5-week treatment, if compared with placebo (p < 0.001). In summary, administration of a medical device, based on hyaluronic acid and chondroitin sulfate, improves gastritis-related upper abdominal pain/discomfort and decreases mucosal erosions, blood oozing, and hyperemia (redness)/edema at 5-week follow-up in patients affected by gastritis.

A review of pharmacotherapy for treating gastroesophageal reflux disease (GERD)

INTRODUCTION

Medical therapy of gastroesophageal reflux disease (GERD) is based on the use of proton pump inhibitors (PPIs) as first choice treatment. Despite their effectiveness, about 20-30% of patients report an inadequate response and alternative drugs are required. Areas covered: This review provides an overview of current pharmacotherapy for treating GERD by showing the results of PPIs, reflux inhibitors, antidepressants and mucosa protective medications. Expert opinion: Medical therapy of GERD does not definitely cure the disease, because even PPIs are not able to change the key factors responsible for it. However, they remain the mainstay of medical treatment, allowing us to alleviate symptoms, heal esophagitis and prevent complications in the majority of cases. Nevertheless, many patients do not respond, because acid does not play any pathogenetic role. Prokinetics and reflux inhibitors have the potential to control motor abnormalities, but the results of clinical trials are inconsistent. Antidepressant drugs are effective in specific subgroups of NERD patients with visceral hypersensitivity, but larger, controlled clinical studies are necessary. Protective drugs or medical devices have been recently adopted to reinforce mucosal resistance and preliminary trials have confirmed their efficacy either combined with or as add-on medication to PPIs in refractory patients.

Efficacy and safety of a combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 as a submucosal injection solution for endoscopic resection: pilot study on a swine model

BACKGROUND AND AIMS

 Endoscopic resection techniques require use of submucosal injection. The aim of this study was to assess a new solution that combines hyaluronic acid, chondroitin sulfate, and poloxamer 407 for submucosal injection.

METHODS

 A total of 48 gastric submucosal cushions were created in fresh porcine stomachs using gelafundin (n = 16) or the new solution diluted at 50 % (n = 16), or 80 % (n = 16). The duration of mucosal elevation was measured. In an in vivo model, 10 gastric submucosal cushions were created by injecting 2 mL of the new solution at 80 % and the animal was euthanized 30 minutes after the last injection.

RESULTS

 Submucosal cushions with the new solution at 80 % and 50 % concentration lasted longer than with gelafundin (23.13 ± 15.57, 13.1 ± 6.6, 3.94 ± 1.53 minutes, respectively; P  = 0.000). In the in vivo study, no damage or necrosis was observed in the mucosa or muscularis propria.

CONCLUSION

 The combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 produces a long-lasting submucosal cushion and does not seem to induce acute damage in the tissue making it suitable for submucosal injection.

Randomised clinical trial: mucosal protection combined with acid suppression in the treatment of non-erosive reflux disease - efficacy of Esoxx, a hyaluronic acid-chondroitin sulphate based bioadhesive formulation

BACKGROUND

Several studies have shown that patients with non-erosive reflux disease (NERD) are less responsive to proton pump inhibitors (PPIs) than those with erosive disease as they belong to different subgroups, in whom factors other than acid can trigger symptoms.

AIM

To evaluate whether combined therapy (mucosal protection plus acid suppression) would improve symptom relief compared to PPI treatment alone.

METHODS

In a multicenter, randomised, double-blind trial, 154 patients with NERD were randomised to receive Esoxx (Alfa Wassermann, Bologna, Italy), a hyaluronic acid-chondroitin sulphate based bioadhesive formulation, or placebo, in addition to acid suppression with standard dose PPIs for 2 weeks. Symptoms (heartburn, acid regurgitation, retrosternal pain and acid taste in the mouth) and health-related quality of life (HRQL) were evaluated before and after treatment. The primary endpoint was the proportion of patients with at least a 3-point reduction in the total symptom score.

RESULTS

At the end of treatment, the primary endpoint was reached by 52.6% of patients taking Esoxx compared to 32.1% of those given placebo (P < 0.01). The same was true also for HRQL, evaluated by means of the Short Form-36 questionnaire, which improved with both treatments, but some items were significantly better after Esoxx plus PPI therapy.

CONCLUSION

The synergistic effect of Essox with PPI treatment suggests that mucosal protection added to acid suppression could improve symptoms and HRQL in NERD patients.

Contribution of immunomodulators to gastroesophageal reflux disease and its complications: stromal cells, interleukin 4, and adiponectin

Gastroesophageal reflux disease (GERD) has become the most commonly seen gastrointestinal disorder in outpatient clinics. In the United States, around 20% of the general population experience heartburn on a weekly basis. Although clinical complaints can be mild or moderate, patients with GERD may develop further complications, such as peptic strictures, Barrett's esophagus (BE), and even esophageal adenocarcinoma. Pathologically, GERD is developed as a result of chronic and enhanced exposure of the esophageal epithelium to noxious gastric refluxate. In this review article, we provide an overview of GERD and then focus on the roles of stromal cells, interleukin 4, and adiponectin in GERD and BE. The importance of inflammation and immunomodulators in GERD pathogenesis is highlighted. Targeting the immunomodulators or inflammation in general may improve the therapeutic outcome of GERD, in particular, in those refractory to proton pump inhibitors.

Zn2+-SCMC versus HA for preventing intraperitoneal adhesions: a rat model study

BACKGROUND

Intraperitoneal adhesion is a serious surgical postoperative complication. Using a rat model, we compared the effectiveness of intraperitoneally administered zinc-modified sodium carboxymethyl cellulose (Zn(2+)-SCMC) and hyaluronic acid (HA) in preventing postoperative intraperitoneal adhesions.

MATERIALS AND METHODS

Peritoneal adhesions were induced in 120 Wistar rats by scraping the cecal mucosa. The rats were randomized into a no treatment group (n = 40) or into a treatment group in which 3 ml of HA (n = 40) or Zn(2+)-SCMC (n = 40) was administered intraperitoneally before the abdominal wall was closed. Following sacrifice two weeks later, the intraperitoneal adhesions were scored and tissues were examined histologically using HE staining.

RESULTS

Eight animals died, five in the untreated group (mortality rate, 12.5%), two in the HA group (mortality rate, 5.0%) and one in the Zn(2+)-SCMC group (mortality rate, 2.5%). Relative to the untreated group, the incidence of intraperitoneal adhesions was 77.5% in the HA and 48.7% in the Zn(2+)-SCMC group, with the incidence significantly lower in the Zn(2+)-SCMC group (P < 0.001). Both agents prevented intraperitoneal adhesions by promoting the repair of the abdominal serosa.

CONCLUSIONS

Administration of Zn(2+)-SCMC was more effective in preventing intraperitoneal adhesions than HA.