Preventing intra-abdominal adhesions with a sodium hyaluronate carboxymethylcellulose membrane enabled visualization of hepatic microcirculation

Recent Advances of Biomedical Materials for Prevention of Post-ESD Esophageal Stricture

Esophageal stricture commonly occurs in patients that have suffered from endoscopic submucosal dissection (ESD), and it makes swallowing difficult for patients, significantly reducing their life qualities. So far, the prevention strategies applied in clinical practice for post-ESD esophageal stricture usually bring various inevitable complications, which drastically counteract their effectiveness. Nowadays, with the widespread investigation and application of biomedical materials, lots of novel approaches have been devised in terms of the prevention of esophageal stricture. Biomedical polymers and biomedical-derived materials are the most used biomedical materials to prevent esophageal stricture after ESD. Both of biomedical polymers and biomedical-derived materials possess great physicochemical properties such as biocompatibility and biodegradability. Moreover, some biomedical polymers can be used as scaffolds to promote cell growth, and biomedical-derived materials have biological functions similar to natural organisms, so they are important in tissue engineering. In this review, we have summarized the current approaches for preventing esophageal stricture and put emphasis on the discussion of the roles biomedical polymers and biomedical-derived materials acted in esophageal stricture prevention. Meanwhile, we proposed several potential methods that may be highly rational and feasible in esophageal stricture prevention based on other researches associated with biomedical materials. This review is expected to offer a significant inspiration from biomedical materials to explore more effective, safer, and more economical strategies to manage post-ESD esophageal stricture.

Polypropylene composite hernia mesh with anti-adhesion layer composed of polycaprolactone and oxidized regenerated cellulose

Hernia surgeries are at the top of the general surgery operations. However, visceral adhesion, which is one of the worst complications of these operations, is still a major problem. One of the most preferred methods to prevent adhesion is the use of biomaterials. Polypropylene (PP) mesh is frequently preferred product in clinical applications owing to its mechanically robust structure against deformation within the body. However, PP meshes do not have anti-adhesive properties. Oxidized regenerated cellulose (ORC), on the other hand, is one of the most preferred products in preventing the adhesion in clinical use. ORC is not easily processable due to solubility limitations; and it must be used externally. In this study, for the first time, we designed a composite mesh structure with ORC and produced an antibacterial and anti-adhesive double-sided mesh by electro-spinning ORC micro-particles with poly(ε‑caprolactone) (PCL) on PP mesh to form a composite structure. We conducted in vitro cell culture studies to determine bio-compatibility performances. We evaluated the anti-adhesion and comprehensive bio-compatibility studies through in vivo experiments. The results revealed that ORC presence and optimization of ORC degradation by coating with PCL play an important role in adhesion prevention and introduced a product prototype with efficient anti-adhesion properties.

Strategies to prevent stricture after esophageal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) has been widely applied as a less invasive and more effective method for treating early esophageal cancers such as squamous cell carcinoma and dysplasia of Barrett's esophagus. However, post-ESD esophageal stricture often occurs if patients suffer circumferential mucosal defects of more than three-quarters of the circumference of the esophagus, which makes it difficult for patients to swallow and greatly reduces their quality of life. Moreover, there is currently no standard method to treat post-ESD esophageal stricture, even though it is extraordinarily important to prevent its formation. In recent years, several strategies to prevent esophageal stricture have emerged. These strategies can be classified into pharmacological, mechanical, tissue engineering, and other novel strategies, with each strategy having its own strengths and weaknesses. Although the pharmacological prophylaxis and mechanical strategies are relatively mature, they still have their drawbacks like high time-consumption, the occurrence of re-stricture, and significant side effects. Tissue engineering strategies and other novel strategies have shown promising preliminary results, but more clinical trials are needed. In this review, we discuss these strategies, with a particular focus on tissue engineering strategies and other novel strategies. It is hoped that this discussion will aid in finding more effective and safer strategies to prevent esophageal stricture.

A Polypropylene-Integrated Bilayer Composite Mesh with Bactericidal and Antiadhesive Efficiency for Hernia Operations

Polypropylene (PP) mesh has been widely used in hernia fixation operations for more than one hundred years, and peritoneal adhesion is still one of the main complications after hernia fixation operations. For preventing peritoneal adhesion, many solutions have been offered, including gel systems, adhesion barrier membranes, and bilayer meshes. Among these, bilayer meshes come to the forefront as they serve for both hernia repair and adhesion prevention. In this study, we developed an easy and effective method to produce a multifunctional PP-integrated bilayer mesh composed of poly(lactic-co-glycolic acid) and chitosan with no need for neutralization. We made the composite mesh by electrospinning a layer onto the PP mesh. We evaluated the material characteristics, in vitro bactericidal activities, and interactions between the cells and materials. Then, we conducted in vivo efficiency studies. The results proved that the PP-integrated bilayer composite mesh is bactericidal against Escherichia coli and Staphylococcus aureus, is tissue-compatible, and supremely prevents adhesion.

Design and evaluation of mucoadhesive oral films containing sodium hyaluronate using multivariate data analysis

CONTEXT

Mucoadhesive oral films, with their prolonged residence time at the site of application, offer a promising approach for protection of the oral lesion surface. The addition of sodium hyaluronate of different molecular weights as a second mucoadhesive polymer into the film matrix could positively influence the physico-mechanical and mucoadhesive properties of films.

OBJECTIVE

The aim of this study was to investigate the formulation of a monolayered film matrix containing varying amounts of sodium hyaluronate and to test the properties of such matrices by applying different characterization methods.

MATERIALS AND METHODS

Film matrix was composed of two mucoadhesive polymers, carmellose sodium and sodium hyaluronate, plasticized with glycerol. Resulting films were characterized with regard to their viscosity and physico-mechanical properties.

RESULTS AND DISCUSSION

Multivariate data analysis was employed to evaluate the influence of varying amounts of mucoadhesive polymers on the main mucoadhesive oral films' properties. The lower content of sodium hyaluronate caused improvements in mechanical properties and residence time on the artificial oral mucosa, both of which are the main characteristics that determine the quality of the final product.

CONCLUSIONS

The best results were obtained by samples containing carmellose sodium with a small amount of sodium hyaluronate (about 0.5% in casting dispersion).

Prevention of Esophageal Strictures After Endoscopic Submucosal Dissection: A Promising Therapy Using Carboxymethyl Cellulose Sheets

BACKGROUND

Esophageal stricture is one of the serious adverse events following endoscopic submucosal dissection (ESD). However, optimum preventive techniques are still lacking.

AIMS

Our primary objective was to evaluate the incidence of post-ESD esophageal stricture with the application of carboxymethyl cellulose (CMC) sheets. Secondary objectives were to determine the number of sessions of endoscopic balloon dilatation (EBD) required to resolve post-ESD strictures and the incidence rate of peri-operative adverse events.

METHODS

This was a pilot, single-center, prospective study. Seven patients who had high risks of developing post-ESD esophageal stricture were enrolled into our study. CMC sheets were applied to the mucosal defects immediately after the completion of ESD. Patients were monitored and reviewed after ESD to detect any adverse events.

RESULTS

The incidence rate of post-operative stricture was 57 % (4/7 patients). Among patients who required EBD, the number of sessions performed was 2.8 ± 2.2. No serious post-operative adverse events were reported.

CONCLUSION

The use of CMC sheets appears to be a safe and effective prophylactic treatment for esophageal stricture following extensive ESD.

Safety and Efficacy of Sodium Hyaluronate Gel and Chitosan in Preventing Postoperative Peristomal Adhesions After Defunctioning Enterostomy: A Prospective Randomized Controlled Trials

Peristomal adhesions complicate closure of defunctioning enterostomy. The efficacy and safety of sodium hyaluronate gel and chitosan in preventing postoperative adhesion have not been extensively studied. This study aims to evaluate the safety and efficacy of sodium hyaluronate gel and chitosan in the prevention of postoperative peristomal adhesions.This was a prospective randomized controlled study. One hundred and fourteen patients undergoing defunctioning enterostomy were enrolled. Patients were randomly assigned to receive sodium hyaluronate gel (SHG group) or chitosan (CH group) or no antiadhesion treatment (CON group) during defunctioning enterostomy. The safety outcomes included toxicities, stoma-related complications, and short-term and long-term postoperative complications. Eighty-seven (76.3%) of the 114 patients received closure of enterostomy, during which occurrence and severity of intra-abdominal adhesions were visually assessed by a blinded assessor.Incidence of adhesion appears to be lower in patients received sodium hyaluronate gel or chitosan but differences did not reach a significant level (SHG group vs CH group vs CON group: 62.1% vs 62.1% vs 82.8%, P = 0.15). Compared with the CON group, severity of postoperative adhesion was significantly decreased in the SHG and CH group (SHG group vs CH group vs CON group: 31.0% vs 27.6% vs 62.1%; P = 0.01). There was no significant difference in the occurrence of postoperative complications and other safety outcomes among the 3 groups.Sodium hyaluronate gel or chitosan smeared around the limbs of a defunctioning enterostomy was safe and effective in the prevention of postoperative peristomal adhesions.

Comprehensive review on additives of topical dosage forms for drug delivery

Skin is the largest organ of the human body and plays the most important role in protecting against pathogen and foreign matter. Three important modes such as topical, regional and transdermal are widely used for delivery of various dosage forms. Among these modes, the topical dosage forms are preferred because it provides local therapeutic activity when applied to the skin or mucous membranes. Additives or pharmaceutical excipients (non-drug component of dosage form) are used as inactive ingredients in dosage form or tools for structuring dosage forms. The main use of topical dosage form additives are controling the extent of absorption, maintaining the viscosity, improving the stability as well as organoleptic property and increasing the bulk of the formulation. The overall goal of this article is to provide the clinician with information related to the topical dosage form additives and their current major applications against various diseases.