Design of fluorinated stealth poly(ε-caprolactone) nanocarriers

The covalent functionalization of polymers with fluorinated moieties represents a promising strategy for the development of multimodal systems. Moreover, polymer fluorination often endows the resulting nanocarriers with improved colloidal stability in the biological environment. In this work, we developed fluorinated pegylated (PEG) biodegradable poly(ε-caprolactone) (PCL) drug nanocarriers showing both high colloidal stability and stealth properties, as well as being (19F)-Nuclear Magnetic Resonance (NMR) detectable. The optimized nanocarriers were obtained mixing a PEG-PCL block copolymer with a nonafluoro-functionalized PCL polymer. The role of PEGylation and fluorination on self-assembly and colloidal behavior of the obtained nanoparticles (NPs) was investigated, as well as their respective role on stealth properties and colloidal stability. To prove the feasibility of the developed NPs as potential 19F NMR detectable drug delivery systems, a hydrophobic drug was successfully encapsulated, and the maintenance of the relevant 19F NMR properties evaluated. Drug-loaded fluorinated NPs still retained a sharp and intense 19F NMR signal and good relaxivity parameters (i.e., T1 and T2 relaxation times) in water, which were not impaired by drug encapsulation.

Centella asiatica and lipoic acid, or a combination thereof, inhibit monocyte adhesion to endothelial cells from umbilical cords of gestational diabetic women

BACKGROUND AND AIMS

Diabetes mellitus is associated with inflammatory endothelial activation and increased vascular leukocyte adhesion molecule expression, both playing a prominent role in the development of vascular complications. Centella asiatica (CA) and Lipoic Acid (LA) have shown anti-inflammatory and anti-oxidant properties in a variety of experimental models; however, their action on human umbilical vein endothelial cells (HUVECs), chronically exposed to hyperglycemia and pro-inflammatory environment during pregnancy, is still unknown.

METHODS AND RESULTS

In HUVECs from umbilical cords of gestational diabetic (GD) or healthy (C) women, both CA and LA affected tumor necrosis factor-α (TNF-α)-induced inflammation, being associated with a significant decrease in vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression (western blot) and exposure (flow cytometry), as well as monocyte-HUVECs interaction (adhesion assay). Notably, this was associated with a significant reduction of an index of nitro-oxidative stress, such as the intracellular peroxynitrite levels (fluorescence detection by cytometric analysis), Mitogen-Activated Protein kinase (p44/42 MAPK) expression/phosphorylation levels and Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) cytoplasm-nucleus translocation (flow cytometry). Overall our results indicate that both CA and LA used separately, and even better when combined, are effective to reduce the inflammatory response in TNF-α-treated HUVECs. Notably, this was more significant in GD than in C-HUVECs and also evident at baseline.

CONCLUSION

In conclusion, our in vitro study demonstrates that both CA and LA, or a combination thereof, are able to mitigate the potentially dangerous effects on the endothelium of chronic exposure to hyperglycemia in vivo.

Effects of long-term treatment with pioglitazone on cognition and glucose metabolism of PS1-KI, 3xTg-AD, and wild-type mice

In this study, we investigated the effects of long-term (9-month) treatment with pioglitazone (PIO; 20 mg/kg/d) in two animal models of Alzheimer's disease (AD)-related neural dysfunction and pathology: the PS1-KI(M146V) (human presenilin-1 (M146V) knock-in mouse) and 3xTg-AD (triple transgenic mouse carrying AD-linked mutations) mice. We also investigated the effects on wild-type (WT) mice. Mice were monitored for body mass changes, fasting glycemia, glucose tolerance, and studied for changes in brain mitochondrial enzyme activity (complexes I and IV) as well as energy metabolism (lactate dehydrogenase (LDH)). Cognitive effects were investigated with the Morris water maze (MWM) test and the object recognition task (ORT). Behavioral analysis revealed that PIO treatment promoted positive cognitive effects in PS1-KI female mice. These effects were associated with normalization of peripheral gluco-regulatory abnormalities that were found in untreated PS1-KI females. PIO-treated PS1-KI females also showed no statistically significant alterations in brain mitochondrial enzyme activity but significantly increased reverse LDH activity.PIO treatment produced no effects on cognition, glucose metabolism, or mitochondrial functioning in 3xTg-AD mice. Finally, PIO treatment promoted enhanced short-term memory performance in WT male mice, a group that did not show deregulation of glucose metabolism but that showed decreased activity of complex I in hippocampal and cortical mitochondria. Overall, these results indicate metabolically driven cognitive-enhancing effects of PIO that are differentially gender-related among specific genotypes.