Cellulose nanocrystals are effective in inhibiting host cell bacterial adhesion.

The use of cellulose nanocrystals (CNCs) as a biomaterial able to inhibit host cell bacterial adhesion is described. Pre-incubation of E. coli ATCC 25922 with a suspension of 0.1% CNCs afforded a significant 2 log reduction of bacterial adhesion to the intestinal cell monolayer HT29. This effect could be attributed to the interaction between the CNCs and the bacterial cell surface as confirmed using fluorescence microscopy experiments.

Microencapsulation of new probiotic formulations for gastrointestinal delivery: in vitro study to assess viability and biological properties.

The paper describes the preparation of new probiotic formulations based on chitosan-coated alginate microcapsules containing three different probiotic strains, Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070, and Bifidobacterium animalis subsp. lactis PBS075 taken individually and as a mixture of them. The effects of microencapsulation on the viability of the strains in conditions simulating the gastrointestinal tract and under industrial processes conditions were studied. In addition, an evaluation of their probiotic properties was also investigated by in vitro tests on the human intestinal cell line HT-29 to explore the effect of microencapsulation on health beneficial effect of the considered strains. Non-encapsulated cells were completely destroyed when exposed to simulated gastric juice and other stress conditions, while encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice and heat and osmotic treatment. Moreover, in this study, the effect of the various microencapsulated probiotic strain formulations was compared with analogous formulations also containing the ß-glucan Pleuran. The microencapsulation effectively protected the selected bacteria, as single strain and as a mixture of the three strains in both the formulations with and without Pleuran, from simulating gastrointestinal tract and industrial process conditions in delivering the viable cells without any significant adverse effect on their functionalities. The comparative study of the immunomodulatory properties of each single strain and the mixture of the three strains revealed a synergistic effect of the probiotic mixture, but no appreciable difference between the two kinds of formulations could be detected, as the effect of Pleuran is covered by the higher potential of the probiotic strains.

Evaluation of the probiotic properties of new Lactobacillus and Bifidobacterium strains and their in vitro effect.

Probiotic ingestion is recommended as a preventive approach to maintain the balance of the intestinal microbiota and to enhance the human well-being. During the whole life of each individual, the gut microbiota composition could be altered by lifestyle, diet, antibiotic therapies and other stress conditions, which may lead to acute and chronic disorders. Hence, probiotics can be administered for the prevention or treatment of some disorders, including lactose malabsorption, acute diarrhoea, irritable bowel syndrome, necrotizing enterocolitis and mild forms of inflammatory bowel disease. The probiotic-mediated effect is an important issue that needs to be addressed in relation to strain-specific probiotic properties. In this work, the probiotic properties of new Lactobacillus and Bifidobacterium strains were screened, and their effects in vitro were evaluated. They were screened for probiotic properties by determining their tolerance to low pH and to bile salts, antibiotic sensitivity, antimicrobial activity and vitamin B8, B9 and B12 production, and by considering their ability to increase the antioxidant potential and to modulate the inflammatory status of systemic-miming cell lines in vitro. Three out of the examined strains presenting the most performant probiotic properties, as Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070 and Bifidobacterium animalis subsp. lactis PBSO75, were evaluated for their effects also on human intestinal HT-29 cell line. The obtained results support the possibility to move to another level of study, that is, the oral administration of these probiotical strains to patients with acute and chronic gut disorders, by in vivo experiments.

Beta amyloid aggregation inhibitors: small molecules as candidate drugs for therapy of Alzheimer's disease.

The progressive production and subsequent accumulation of ß-amyloid (Aß), a proteolytic fragment of the membrane-associated amyloid precursor protein (APP), plays a central role in Alzheimer's Disease (AD). Aß is released in a soluble form that may be responsible for cognitive dysfunction in the early stages of the disease, then progressively forms oligomeric, multimeric and fibrillar aggregates, triggering neurodegeneration. Eventually, the aggregation and accumulation of Aß culminates with the formation of extracellular plaques, one of the morphological hallmarks of the disease, detectable post-mortem in AD brains. In this review we report the known structural features of amyloid peptides and fibrils, and we give an overview of all small molecules that have been found to interact with Aß aggregation. Deeper knowledge of the mechanism leading to amyloid fibrils along with their molecular structure and the molecular interactions responsible for activity of small molecules could supply useful information for the design of new AD therapeutic agents.

Synthesis and biological evaluation of an anticancer vaccine containing the C-glycoside analogue of the Tn epitope.

The C-saccharide analogue of the GalNAc (Tn epitope) has been covalently linked to the T cell epitope peptide (328)(-)(340)OVA using a chemoselective convergent synthetic approach. In this way, a non-hydrolyzable synthetic vaccine was obtained composed by a B epitope conjugated to a T cell epitope. This compound was tested in a proliferation assay with spleen cells from DO11.10 mice. The molecule was recognized by transgenic T cells although at a slightly lower efficiency if compared with the reference peptide OVA. An additional experiment with dendritic cells fixed with glutaraldehyde shows that the glycopeptide can bind to extracellular MHC molecules without need of internalization and processing and that the C-glycoside part does not interfere with TCR recognition. These observations constitute an important starting point for the use of this molecule as vaccine against the Tn-expressing TA3-Ha mouse mammary carcinoma.

A highly convergent approach to O- and N-linked glycopeptide analogues.

Deprotected C-glycopyranosyl-ketones have been conjugated by a chemoselective approach to a peptide or an amino acid bearing an aminooxy group on the N-terminus or on the side-chain, respectively. The coupling reaction, performed in aqueous media, does not require protecting groups on the peptide or saccharide moieties, nor auxiliary coupling reagents.