Proteinaceous microspheres as a delivery system for carvacrol and thymol in antibacterial applications.

There is an urgent need for new materials with antimicrobial activity. Phenolic essential oil (EO) compounds with Generally Recognized As Safe (GRAS) status are attractive candidates, but they need suitable delivery systems to overcome specific drawbacks. Core-shell microspheres (MSs) of Bovine Serum Albumin (BSA) or Human Serum Albumin (HSA) encapsulating such active compounds in the oil phase are a delivery system that is novel in combination with phenolic EO compounds. Moreover, the EO compounds can also be assembled in an oil shell around a protein core by choosing an appropriate oil phase. A facile sonochemical fabrication method, which can be easily scaled-up, is developed with full characterization of the resulting EO-containing MSs by optical and electron microscopy. Bacterial growth experiments with E. coli including TEM of treated cells confirm antibacterial activity. In the case of carvacrol, the corresponding MSs are found to be both more bioactive and more stable than the free biocide.

Mimicking Neuroligin-2 Functions in ß-Cells by Functionalized Nanoparticles as a Novel Approach for Antidiabetic Therapy.

Both pancreatic ß-cell membranes and presynaptic active zones of neurons include in their structures similar protein complexes, which are responsible for mediating the secretion of bioactive molecules. In addition, these membrane-anchored proteins regulate interactions between neurons and guide the formation and maturation of synapses. These proteins include the neuroligins (e.g., NL-2) and their binding partners, the neurexins. The insulin secretion and maturation of ß-cells is known to depend on their 3-dimensional (3D) arrangement. It was also reported that both insulin secretion and the proliferation rates of ß-cells increase when cells are cocultured with clusters of NL-2. Use of full-length NL-2 or even its exocellular domain as potential ß-cell functional enhancers is limited by the biostability and bioavailability issues common to all protein-based therapeutics. Thus, based on molecular modeling approaches, a short peptide with the potential ability to bind neurexins was derived from the NL-2 sequence. Here, we show that the NL-2-derived peptide conjugates onto innovative functional maghemite (γ-Fe2O3)-based nanoscale composite particles enhance ß-cell functions in terms of glucose-stimulated insulin secretion and protect them under stress conditions. Recruiting the ß-cells' "neuron-like" secretory machinery as a target for diabetes treatment use has never been reported before. Such nanoscale composites might therefore provide a unique starting point for designing a novel class of antidiabetic therapeutic agents that possess a unique mechanism of action.