Magnetically Controlled Carbonate Nanocomposite with Ciprofloxacin for Biofilm Eradication.

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.

Microbiota and cancer: host cellular mechanisms activated by gut microbial metabolites.

In recent years, more and more data indicate the effect of human microbiota on carcinogenesis. Despite the numerous studies on the relationship between gut microbiota and carcinogenesis, the exact mechanisms of this interaction are not well studied. It becomes apparent that this relationship can be mediated by microbial metabolites. Mechanisms of some well-known bacterial genotoxins and oncogenes, such as colibactin, CagA, IpgD, VirA, P37, have been studied in detail. At the same time, a role in carcinogenesis of a large group of gut microbial metabolites, including short-chain fatty acids, polyamines, and products of polyphenol and tryptophan catabolism, is less well understood. However, more and more evidence data show the effect of bacterial metabolites on cancer development and progression. In this review, we summarize relevant data regarding the possible mechanisms that can account for the effects of gut microbial metabolites mentioned above in carcinogenesis.

Heparin-coated iron oxide nanoparticles: application as a liver contrast agent, toxicity and pharmacokinetics.

The prepared heparin-coated iron oxide nanoparticles (Hep-IONPs) contrasted cholangioma tumors in the liver in T2 MRI. The NPs were not toxic to rats and rabbits after 14 days of consecutive IV injections as observed from the monitoring of the body weight and biochemical and hematological parameters. No embryotoxic or immunotoxic side effects of the material were detected. However, we observed mutagenicity of iron oxide NPs in the Ames test and micronucleus assay. The pharmacokinetic studies showed that Hep-IONPs circulated in the blood for 14 days after IV injection. The liver iron level reached its maximum after 6 hours and slowly decreased within 30 days. Altogether, these results suggest that the synthesized Hep-IONPs are promising for use as the MRI contrast agent to identify liver malignancies.