Pectin-honey hydrogel: Characterization, antimicrobial activity and biocompatibility.

BACKGROUND: Novel pectin-honey hydrogels have been developed and characterized as medical device. Ideally, a wound dressing should maintain optimal fluid affinity, permit moisture evaporation, protect the wound from microbes, and have shape-conformability, biocompatibility, and antibacterial activity. OBJECTIVE: A novel, simple and fast method to produce pectin-honey wound dressings is described. METHODS: The properties of these pectin-honey hydrogels were investigated, including swelling ability, water vapour transmission rate, hydrogen peroxide production, methylglyoxal content and antibacterial activity. Biocompatibility was assessed by proliferation assays using cultured fibroblast cells and by in vivo study with subcutaneous and intraperitoneal implantation in rats. RESULTS: Hydrogel showed a good water vapour transmission rate, fluid uptake and were not cytotoxic for fibroblasts. The hydrogel demonstrated good antibacterial activity toward clinically relevant pathogens, including S. aureus and E. coli. Biocompatibility was confirmed by the measurement of plasma levels of interleukin (IL)1 beta, IL-6, tumour necrosis factor (TNF) alpha, and prostaglandin (PG)E2. No histological changes were observed. CONCLUSIONS: The presence of a natural active component, conformability, and complete resorbability are the main characteristics of this new biocompatible biomaterial that is well tolerated by the body, possibly improves healing, may be used for surgical complications prevention, with a simple and inexpensive production process.

Vitamin C, Aging and Alzheimer's Disease.

Accumulating evidence in mice models of accelerated senescence indicates a rescuing role of ascorbic acid in premature aging. Supplementation of ascorbic acid appeared to halt cell growth, oxidative stress, telomere attrition, disorganization of chromatin, and excessive secretion of inflammatory factors, and extend lifespan. Interestingly, ascorbic acid (AA) was also found to positively modulate inflamm-aging and immunosenescence, two hallmarks of biological aging. Moreover, ascorbic acid has been shown to epigenetically regulate genome integrity and stability, indicating a key role of targeted nutrition in healthy aging. Growing in vivo evidence supports the role of ascorbic acid in ameliorating factors linked to Alzheimer's disease (AD) pathogenesis, although evidence in humans yielded equivocal results. The neuroprotective role of ascorbic acid not only relies on the general free radical trapping, but also on the suppression of pro-inflammatory genes, mitigating neuroinflammation, on the chelation of iron, copper, and zinc, and on the suppression of amyloid-beta peptide (Aß) fibrillogenesis. Epidemiological evidence linking diet, one of the most important modifiable lifestyle factors, and risk of Alzheimer's disease is rapidly increasing. Thus, dietary interventions, as a way to epigenetically modulate the human genome, may play a role in the prevention of AD. The present review is aimed at providing an up to date overview of the main biological mechanisms that are associated with ascorbic acid supplementation/bioavailability in the process of aging and Alzheimer's disease. In addition, we will address new fields of research and future directions.