Coordination complexes of zinc and manganese based on pyridine-2,5-dicarboxylic acid N-oxide: DFT studies and antiproliferative activities consideration

Mechanical Properties of Low-Molecular-Weight Peptide Hydrogels Improved by Thiol-Ene Click Chemistry

Low-molecular-weight peptide hydrogels can be formed by self-assembly through weak interactions, but the application of the hydrogel is influenced by its weak mechanical properties. Therefore, it is important to construct low-molecular-weight peptide hydrogels with excellent mechanical properties. In this work, we designed the pentapeptide molecule Fmoc-FFCKK-OH (abbreviated as FFCKK) with a sulfhydryl group, and another low-molecular-weight cross-linker N,N'-methylenebis(acrylamide) (MBA) was introduced to construct a hydrogel with excellent mechanical properties. The secondary structure change process of FFCKK and the assembly mechanism of hydrogel were analyzed using theoretical calculations and experimental characterizations. The occurrence of thiol-ene click chemistry provides covalent interaction in the hydrogel, and the synergistic effect ofcovalent interaction and hydrogen bonding improves the mechanical properties of the hydrogel by nearly 10-fold. The hydrogel was observed to be able to withstand a stress of 368 Pa and to break in a layer-by-layer manner by compression testing. The micromechanics of the hydrogels were characterized, and the excellent mechanical properties of the hydrogels were confirmed. The synergistic approach provides a new idea for the preparation of low-molecular-weight peptide hydrogels and facilitates the expansion of their potential applications in biomedical fields.

Pairing 3D-Printing with Nanotechnology to Manage Metabolic Syndrome

Introduction

This work was aimed to develop a Curcuma oil-based self-nanoemulsifying drug delivery system (SNEDDS) 3D-printed polypills containing glimepiride (GMD) and rosuvastatin (RSV) for treatment of dyslipidemia in patients with diabetes as a model for metabolic syndrome (MS).

Methods

Compartmentalized 3D printed polypills were prepared and studied in streptozotocin/poloxamer induced diabetic/dyslipidemic rats. The pharmacokinetic parameters of GMD and RSV in the prepared polypills were evaluated. Blood glucose level, lipid profile, antioxidant, and biochemical markers activities were investigated. Also, histopathological examination of the liver and pancreas was carried out. The atherosclerotic index, the area of islets of Langerhans, and liver steatosis lesion scores were calculated.

Results

The developed SNEDDS-loaded GMD/RSV polypills showed acceptable quality control characteristics with a high relative bioavailability of 217.16% and 224.28% for GMD and RSV, respectively, when compared with the corresponding non-SNEDDS pills. The prepared polypills showed dramatic lowering in blood glucose levels and substantial improvement in lipid profile and hepatic serum biomarkers as well as remarkable decrease in serum antioxidants in response to Poloxamer 407 intoxication. The prepared polypills decreased the risk of atherosclerosis and coronary disease by boosting the level of high-density lipoprotein and lowering both triglyceride and low-density lipoprotein. Microscopic examination showed normal hepatic sinusoids and high protection level with less detectable steatosis in the examined hepatocytes. Normal size pancreatic islets with apparently normal exocrine acini and pancreatic duct were also noticed.

Conclusion

This formulation strategy clearly shows the potential of the developed polypills in personalized medicine for treatment of patients with MS.

On the importance of π-stacking interactions in the complexes of copper and zinc bearing pyridine-2,6-dicarboxylic acid N-oxide and N-donor auxiliary ligands

Using N- and O-donor ligands in a mixed-ligand system, three new coordination complexes have been X-ray characterized, exhibiting strong π–π stacking interactions.