Mucosal concentration of basic fibroblast growth factor in the healing process in human giant gastric ulcers

Nanocomposite hyaluronic acid-based hydrogel for the treatment of esophageal fistulas

Fistulas are abnormal connections between two body parts that can impair the quality of life. The use of biological glues represents the least invasive procedure to fill the fistula; however, it is limited by the need of multiple injections, the persistence of infection and the failure in the treatment of high-output fistulas. We describe herein the use of an injectable nanocomposite hydrogel that is able to form in situ a tissue-mimicking matrix as an innovative material for the treatment of esophageal fistulas. Injectable hydrogels that have the dual advantage of being implantable with a minimally invasive approach and of adapting their shape to the target cavity, while the introduction of mesoporous silica nanoparticles opens the possibility of drug/biomolecules delivery.

The hydrogel is based on hyaluronic acid (HA), the crosslinking process occurs at physiological conditions leading to a hydrogel made of >96% by water and with a large-pore micro-architecture. The kinetic profile of the hydrogel formation is studied as a function of HA molecular weight and concentration with the aim of designing a material that is easily injectable with an endoscopic needle, is formed in a time compatible with the surgical procedure and has final mechanical properties suitable for cell proliferation. The in vivo experiments (porcine model) on esophageal-cutaneous fistulas, showed improved healing in the animals treated with the hydrogel compared with the control group.

New devices and techniques for endoscopic closure of gastrointestinal perforations

Gastrointestinal perforations, which need to be managed quickly, are associated with high morbidity and mortality. Treatments used to close these perforations range from surgery to endoscopic therapy. Nowadays, with the development of new devices and techniques, endoscopic therapy is becoming more popular. However, there are different indications and clinical efficacies between different methods, because of the diverse properties of endoscopic devices and techniques. Successful management also depends on other factors, such as the precise location of the perforation, its size and the length of time between the occurrence and diagnosis. In this study, we performed a comprehensive review of various devices and introduced the different techniques that are considered effective to treat gastrointestinal perforations. In addition, we focused on the different methods used to achieve successful closure, based on the literature and our clinical experiences.

Risk factors for gastrointestinal complications in aspirin users: review of clinical and experimental data

This paper reviews recent clinical evidence that suggests that aspirin prophylaxis against cardiac and cerebral vascular ischemia is associated with significant gastrointestinal complications. The clinical and experimental evidence to confirm the role of risk factors of concomitant use of nonsteroidal anti-inflammatory drugs (NSAID), tobacco cigarette smoking, and alcohol consumption are discussed. The limitations of long-term acid suppression treatment for the prevention of these complications are considered. Future experimental studies to guide the clinical approach to develop novel and potentially cost-effective management strategies are discussed.

Fibrin glue, healing of gastric mucosal injury, and expression of growth factors: results from a human in vivo study

BACKGROUND

Fibrin glue is used in the endoscopic therapy of bleeding ulcerations. Accelerated closure of ulcers has been attributed to this treatment; the biologic reason, however, remains unclear.

METHODS

Two artificial gastric lesions were induced in healthy, Helicobacter pylori negative volunteers and were treated by injection of either saline solution or fibrin glue. After 72 hours, resulting ulcers were measured and biopsy specimens were taken for immunohistochemistry (to identify proliferating cells and small vessels) and assessment of growth factor messenger RNA (mRNA) expression (platelet derived growth factor, vascular endothelial growth factor, fibroblast growth factor 2 [FGF-2]) by real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

After 72 hours, most lesions exposed to fibrin glue were smaller than the corresponding ones treated with saline solution. The ulcer rim was more pronounced; immunohistochemistry revealed more proliferating cells (p < 0.02 compared with saline solution). The number of microvessels also increased, though this difference did not reach statistical significance (p = 0.10). FGF-2 mRNA expression markedly increased (about 7-fold compared with the control [ p < 0.001], and about 5-fold compared with saline solution [ p < 0.015]); whereas, with respect to platelet derived growth factor and vascular endothelial growth factor mRNAs, only small changes occurred.

CONCLUSIONS

Fibrin glue positively modulates gastric ulcer healing by causing an increase in the number of proliferating cells in the ulcer margin and also possibly enhances the density of microvessels. These changes are accompanied by an enhanced expression of FGF-2, which is known to exert beneficial effects on ulcer healing.