Liposomes loaded with drug–cyclodextrin complexes are widely used as drug delivery systems, especially for species with low aqueous solubility and stability. Investigation of the intimate interactions of macrocycles with liposomes are essential for formulation of efficient and stable drug-in-cyclodextrin-in-liposome carriers. In this work, we reported the preparation of unilamellar vesicles of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) embedded with native β-cyclodextrin and two synthetic derivatives: heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMCD) and heptakis(2,3-di-O-acetyl)-β-cyclodextrin (DACD). We then studied the effect of these macrocycles on the liposomal size, membrane viscosity, and liposomal stability at different temperatures and concentrations. We observed that TMCD and DACD affected vesicle size and the change of size was related to CD concentration. Irrespective of its nature, the macrocycle established interactions with the phospholipidic head groups, preventing cyclodextrins to diffuse into the lipid bilayer, as confirmed by molecular dynamics simulations. Such supramolecular structuring improves liposome stability making these colloid systems promising carriers for biologically active compounds.

The rates of tautomerization of 2-nitrocyclohexanone (2-NCH) have been measured spectrophotometrically at 25.0 ± 0.1 °C in several organic aprotic solvents and their binary mixtures. In cyclohexane the reaction is effectively catalyzed by bases and inhibited by acids while the so-called “spontaneous reaction” appears essentially due to autocatalysis. Apparent second order rate constants (k_app ^B) for the reaction catalyzed by triethylamine (TEA) and pyridine (Pyr) have been obtained. From the experimental k_app ^B values rate constants for the enolization (k₁ ^B) and ketonization (k₋₁ ^B) reactions have been calculated. A Kamlet–Taft type linear solvation energy relationship (LSER) adequately accounts for the observed solvent effects. Activation parameters for both reactions show that solvent effects are mainly entropic in origin and that there is a shift of the transition state from a ketone-like to an enol-like structure on passing from less to more polar solvents.

(1) Background: The aim of this study was to optimize, through a cheap and facile protocol, the covalent functionalization of graphene oxide (GO)-decorated cortical membrane (Lamina^®) in order to promote the adhesion, the growth and the osteogenic differentiation of DPSCs (Dental Pulp Stem Cells); (2) Methods: GO-coated Laminas were fully characterized by Scannsion Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) analyses. In vitro analyses of viability, membrane integrity and calcium phosphate deposition were performed; (3) Results: The GO-decorated Laminas demonstrated an increase in the roughness of Laminas, a reduction in toxicity and did not affect membrane integrity of DPSCs; and (4) Conclusions: The GO covalent functionalization of Laminas was effective and relatively easy to obtain. The homogeneous GO coating obtained favored the proliferation rate of DPSCs and the deposition of calcium phosphate.

Poly(methyl methacrylate) (PMMA) is characterized by high CO₂ capture yield under mild pressures and temperatures. A morphological modification of powdery amorphous PMMA (pPMMA) is carried out by electrospinning to increase the surface/volume ratio of the resulting electrospun PMMAs (ePMMAs). This modification improves the kinetics and the capture yields. The rate constants observed for ePMMAs are two to three times higher than those for pPMMA, reaching 90% saturation values within 5–7 s. The amount of sorbed CO₂ is up to eleven times higher for ePMMAs at 1 °C, and the highest difference in captured CO₂ amount is observed at the lowest tested pressure of 1 MPa. The operating life of the ePMMAs shows a 5% yield loss after ten consecutive runs, indicating good durability. Spent electrospun PMMAs after several cycles of CO₂ sorption-desorption can be regenerated by melting and again electrospinning the molten mass, resulting in a CO₂ capture performance that is undistinguishable from that observed with fresh ePMMA. Scanning electron and atomic force microscopies show a reduction in surface roughness after gas exposure, possibly due to the plasticization effect of CO₂. This study shows the potential of electrospun PMMAs as solid sorbents for carbon capture from natural gas or pre-combustion and oxyfuel combustion processes.