Benefit of a Short Chain Peptide as a Targeting Ligand of Nanocarriers for a Brain-Driven Purpose

Treatment of glioma remains a critical challenge worldwide, since the therapeutic effect is greatly hindered by poor transportation across the blood brain barrier (BBB) and low penetration into tumor cells. In this study, a peptide-conjugated nano-delivery system was explored for the purpose of glioma therapy. A peptide-decorated copolymer was used to prepare nanoparticles (NPs) by a solvent evaporation method. The particle size was in the range of 160.9 ± 3.3–173.5 ± 3.6 nm with monodistribution, and the zeta potentials ranged from −18.6 ± 1.2 to +7.9 ± 0.6 mV showing an increasing trend with R9-peptide. An in vitro cocultured BBB model illustrated the internalization of peptide-conjugated NPs in bEnd.3 cells followed by uptake by U87-MG cells indicating both BBB-crossing and glioma-penetrating abilities. IVIS (In Vivo Imaging System) images revealed that T7-conjugated NPs specifically accumulated in the brain more than peptide-free NPs and had less biodistribution in nontarget tissues than T7/R9 dual-peptide conjugated NPs. The benefit of T7-peptide as a targeting ligand for NPs across the BBB with accumulation in the brain was elucidated.

Effect of α-Hemolysin Producing E. coli in Two Different Mouse Strains in a DSS Model of Inflammatory Bowel Disease

Background: Phylogroup B2 Escherichia coli have been associated with ulcerative colitis (UC). In this study, we aimed to compare colonization with the UC-associated E. coli p19A in different mice strains, to investigate the role of alpha hemolysin in a UC mouse model. Methods: In this study, Sigirr −/− and C57BL/6 mice were chosen, and UC was induced by adding dextran sulfate sodium (DSS) to the drinking water. The mice were pre-treated with ciprofloxacin. p19A expressing luminescence and GFP, alpha-hemolysin knock out p19A-ΔhlyI II, and non-pathogenic lab E. coli DH10B were cultured in LB broth, and orally gavaged into the mice. Colonization with p19A WT was visualized using an in vivo imaging system. Results: p19A WT colonized the colon, ileum, Peyer’s patches, liver, and spleen of infected C57BL/6 and Sigirr −/− mice. A total of 99% of the p19A WT infected C57BL/6 mice and 29% of the p19A WT infected Sigirr −/− mice survived to the 4th post infection day. Conclusion: UC-associated E. coli p19A WT colonized the intestines of DSS-treated mice and caused extra-intestinal infection. Hemolysin is an important factor in this pathogenesis, since isogenic hemolysin mutants did not cause the same inflammation.

Effect of α-Hemolysin Producing E. coli in Two Different Mouse Strains in a DSS Model of Inflammatory Bowel Disease

Background: Phylogroup B2 Escherichia coli have been associated with Ulcerative Colitis (UC). In this study, we aimed to compare colonization with the UC-associated E. coli p19A in different mice strains, to investigate the role of alpha hemolysin in a UC mouse model. Methods: In this study, Sigirr -/- and C57BL/6 mice were chosen, and UC was induced by adding Dextran Sulfate Sodium (DSS) to the drinking water. The mice were pre-treated with ciprofloxacin. p19A expressing luminescence and GFP, alpha-hemolysin knock out p19A-∆hlyI II, and non-pathogenic lab E. coli DH10B were cultured in LB broth, and orally gavaged into the mice. Colonization with p19A WT was visualized using an in-vivo imaging system. Results: p19A WT colonized the colon, ileum, Peyer’s patches, liver, and spleen of infected C57BL/6 and Sigirr -/- mice. A total of 99% of the p19A WT infected C57BL/6 mice and 29% of the p19A WT infected Sigirr -/- mice survived to the 4th post infection day. Conclusion: UC-associated E. coli p19A WT colonized the intestines of DSS-treated mice and caused extra-intestinal infection. Hemolysin is an important factor in this pathogenesis, since isogenic hemolysin mutants did not cause the same inflammation.

Utility of microminipigs for evaluating liver-mediated gene expression in the presence of neutralizing antibody against vector capsid

Adeno-associated virus (AAV) vectors can transduce hepatocytes efficiently in vivo in various animal species, including humans. Few reports, however, have examined the utility of pigs in gene therapy. Pigs are potentially useful in preclinical studies because of their anatomical and physiological similarity to humans. Here, we evaluated the utility of microminipigs for liver-targeted gene therapy. These pigs were intravenously inoculated with an AAV8 vector encoding the luciferase gene, and gene expression was assessed by an in vivo imaging system. Robust transgene expression was observed almost exclusively in the liver, even though the pig showed a low-titer of neutralizing antibody (NAb) against the AAV8 capsid. We assessed the action of NAbs against AAV, which interfere with AAV vector-mediated gene transfer by intravascular delivery. When a standard dose of vector was administered intravenously, transgene expression was observed in both NAb-negative and low-titer (14×)-positive subjects, whereas gene expression was not observed in animals with higher titers (56×). These results are compatible with our previous observations using nonhuman primates, indicating that pigs are useful in gene therapy experiments, and that the role of low-titer NAb in intravenous administration of the AAV vector shows similarities across species.

Dissolving Microneedle Patches for Transdermal Insulin Delivery in Diabetic Mice: Potential for Clinical Applications

In this study, dissolving polymeric microneedle (MN) patches composed of gelatin and sodium carboxymethyl cellulose (CMC) were used to localize insulin. Their in vitro skin insertion capabilities were determined using tissue-marking dye to stain the skin after patches removal. Scanning electron microscopy (SEM) was used to determine changes in the MNs over time, and optical coherence tomography (OCT) was used to monitor their real-time penetration depth. Confocal microscopy images revealed that rhodamine 6G gradually diffuses from the puncture sites to deeper dermal tissue. Using an in vivo imaging system (IVIS), skin areas that received FITC-insulin-loaded MNs were found to present strong fluorescent signals that greatly decreased 1 h after application. Results show that dissolving MNs rapidly release FITC-insulin, and it then gradually diffuses into the skin. This study verifies that using a gelatin/CMC MN patch for insulin delivery achieves satisfactory relative bioavailability compared to a traditional hypodermic injection and can be a promising delivery device for poorly permeable protein drugs such as those used to treat diabetes. Insertion tests on human cadaveric skin demonstrate that dissolving MNs could serve as efficient devices for transdermal drug delivery in clinical practice and that the volar aspect of forearm skin is the ideal location for their applications.