Lecithin nano-liposomal particle as a CRISPR/Cas9 complex delivery system for treating type 2 diabetes.

BACKGROUND: Protein-based Cas9 in vivo gene editing therapeutics have practical limitations owing to their instability and low efficacy. To overcome these obstacles and improve stability, we designed a nanocarrier primarily consisting of lecithin that can efficiently target liver disease and encapsulate complexes of Cas9 with a single-stranded guide RNA (sgRNA) ribonucleoprotein (Cas9-RNP) through polymer fusion self-assembly. RESULTS: In this study, we optimized an sgRNA sequence specifically for dipeptidyl peptidase-4 gene (DPP-4) to modulate the function of glucagon-like peptide 1. We then injected our nanocarrier Cas9-RNP complexes directly into type 2 diabetes mellitus (T2DM) db/db mice, which disrupted the expression of DPP-4 gene in T2DM mice with remarkable efficacy. The decline in DPP-4 enzyme activity was also accompanied by normalized blood glucose levels, insulin response, and reduced liver and kidney damage. These outcomes were found to be similar to those of sitagliptin, the current chemical DPP-4 inhibition therapy drug which requires recurrent doses. CONCLUSIONS: Our results demonstrate that a nano-liposomal carrier system with therapeutic Cas9-RNP has great potential as a platform to improve genomic editing therapies for human liver diseases.

Induced heat property of polyethyleneglycol-coated iron oxide nanoparticles with dispersion stability for hyperthermia.

Fe3O4 nanoparticles have been used for hyperthermia treatment in an attempt to overcome various problems. When using hyperthermia treamtment, it is critical to control the surface modification of the particles. Magnetic nanoparticles tend to aggregate due to strong magnetic dipole--dipole attractions. The particles then have a high surface area and are of larger sizes, posing serious practical limitations. The nanoparticles are used to generate maximum heat and to maintain a constant heating temperature using the minimum magnetic nanoparticles dosage. In this study, we investigated the effect of PEG coated onto Fe3O4 nanoparticles. We tested the dispersion stability and repetitive heating property of nanoparticles for different PEG concentrations under an AC magnetic field. The results confirmed that the nanoparticles on a colloidal system maintained the heating properties of repetitve inductive heating as PEG concentration increased with dispersion stability. The nanoparticles with superior dispersion stability will be appropriate for hyperthermia applications in cancer treatments.

Use of magnetic nanoparticles to visualize threadlike structures inside lymphatic vessels of rats.

A novel application of fluorescent magnetic nanoparticles was made to visualize a new tissue which had not been detectable by using simple stereomicroscopes. This unfamiliar threadlike structure inside the lymphatic vessels of rats was demonstrated in vivo by injecting nanoparticles into lymph nodes and applying magnetic fields on the collecting lymph vessels so that the nanoparticles were taken up by the threadlike structures. Confocal laser scanning microscope images of cryosectioned specimens exhibited that the nanoparticles were absorbed more strongly by the threadlike structure than by the lymphatic vessels. Further examination using a transmission electron microscope revealed that the nanoparticles had been captured between the reticular fibers in the extracellular matrix of the threadlike structures. The emerging technology of nanoparticles not only allows the extremely elusive threadlike structures to be visualized but also is expected to provide a magnetically controllable means to investigate their physiological functions.