Analysis of biotinylated generation 4 poly(amidoamine) (PAMAM) dendrimer distribution in the rat brain and toxicity in a cellular model of the blood-brain barrier.

Dendrimers are highly customizable nanopolymers with qualities that make them ideal for drug delivery. The high binding affinity of biotin/avidin provides a useful approach to fluorescently label synthesized dendrimer-conjugates in cells and tissues. In addition, biotin may facilitate delivery of dendrimers through the blood-brain barrier (BBB) via carrier-mediated endocytosis. The purpose of this research was to: (1) measure toxicity using lactate dehydrogenase (LDH) assays of generation (G)4 biotinylated and non-biotinylated poly(amidoamine) (PAMAM) dendrimers in a co-culture model of the BBB, (2) determine distribution of dendrimers in the rat brain, kidney, and liver following systemic administration of dendrimers, and (3) conduct atomic force microscopy (AFM) on rat brain sections following systemic administration of dendrimers. LDH measurements showed that biotinylated dendrimers were toxic to cell co-culture after 48 h of treatment. Distribution studies showed evidence of biotinylated and non-biotinylated PAMAM dendrimers in brain. AFM studies showed evidence of dendrimers only in brain tissue of treated rats. These results indicate that biotinylation does not decrease toxicity associated with PAMAM dendrimers and that biotinylated PAMAM dendrimers distribute in the brain. Furthermore, this article provides evidence of nanoparticles in brain tissue following systemic administration of nanoparticles supported by both fluorescence microscopy and AFM.

Probiotics for Gastrointestinal and Liver Diseases: An Updated Review of the Published Literature.

BACKGROUND: Probiotics can be viewed as biological agents that modify the intestinal microbiota and certain cytokine profiles, which can lead to an improvement in certain gastrointestinal diseases, including diarrhea, inflammatory bowel disease, and liver disease. DISCUSSION: Consumption of probiotics in their various forms, including yogurt, functional foods, and dietary supplements, is frequently encountered worldwide. Often, however, the correct prescription of these agents is dampened due to a lack of knowledge of the scientific evidence and the different presentations and microbial compositions of the currently available probiotic options. Here, we provide an up-to-date review of the evidence of probiotics in the prevention and treatment of various gastrointestinal diseases. OBJECTIVE: Consumption of probiotics in their various forms, including yogurt, functional foods, and dietary supplements, is frequently encountered worldwide. Often, however, the correct prescription of these agents is dampened due to a lack of knowledge of the scientific evidence and the different presentations and microbial compositions of the currently available probiotic options. METHODS/RESULTS: Here, we provide an up-to-date review of the evidence of probiotics in the prevention and treatment of various gastrointestinal diseases. CONCLUSION: While not efficacious in every disease process studied, probiotics have demonstrated some benefit in several specific gastrointestinal and liver diseases.