Characterization of oligosaccharide-functionalized hyperbranched poly(ethylene imine) and their complexes with retinol in aqueous solution

Structural elucidation of an active polysaccharide from Radix Puerariae lobatae and its protection against acute alcoholic liver disease

Radix Pueraria lobata can be used as medicine and food, whose polysaccharide is one of the main bioactive ingredients. To explore the effect and mechanism of Pueraria lobata polysaccharide, a homogeneous and novel water-soluble polysaccharide (PLP1) was successfully isolated and purified from P. lobata by column chromatography in the current study. Structure analysis revealed that PLP1 (Mw = 10.43 kDa) was constituted of the residues including (1 → 4)-α-d-glucose and (1 → 4, 6)-α-d-glucose, which were linked together at a ratio of 5:1 and represented the main glycosidic units. In vitro experiments indicated that PLP1 exhibited a better free radical-scavenging ability than amylose and amylopectin, meanwhile in vivo experiments indicated that PLP1 effectively protected against liver injury in mice with acute ALD through significantly inhibiting oxidative stress to regulate lipid metabolism, increasing short-chain fatty acid production, and maintaining intestinal homeostasis by regulating intestinal flora. Taken together, our results illustrate that PLP1 can regulate intestinal microecology as a feasible therapeutic agent for protecting against ALD on the ground of the gut-liver axis, thus laying a theoretical foundation for the rational exploitation and utilization of P. lobata resources in the clinic.

DOTA Glycodendrimers as Cu(II) Complexing Agents and Their Dynamic Interaction Characteristics toward Liposomes

Copper (Cu)(II) ions, mainly an excess amount, play a negative role in the course of several diseases, like cancers, neurodegenerative diseases, and the so-called Wilson disease. On the contrary, Cu(II) ions are also capable of improving anticancer drug efficiency. For this reason, it is of great interest to study the interacting ability of Cu(II)-nanodrug and Cu(II)-nanocarrier complexes with cell membranes for their potential use as nanotherapeutics. In this study, the complex interaction between 1,4,7,10-tetraazacyclododecan-N,N',N'',N'''-tetraacetic acid (DOTA)-functionalized poly(propyleneimine) (PPI) glycodendrimers and Cu(II) ions and/or neutral and anionic lipid membrane models using different liposomes is described. These interactions were investigated via dynamic light scattering (DLS), ζ-potential (ZP), electron paramagnetic resonance (EPR), fluorescence anisotropy, and cryogenic transmission electron microscopy (cryo-TEM). Structural and dynamic information about the PPI glycodendrimer and its Cu(II) complexes toward liposomes was obtained via EPR. At the binding site Cu-N₂O₂ coordination prevails, while at the external interface, this coordination partially weakens due to competitive dendrimer-liposome interactions, with only small liposome structural perturbation. Fluorescence anisotropy was used to evaluate the membrane fluidity of both the hydrophobic and hydrophilic parts of the lipid bilayer, while DLS and ZP allowed us to determine the distribution profile of the nanoparticle (PPI glycodendrimer and liposomes) size and surface charge, respectively. From this multitechnique approach, it is deduced that DOTA-PPI glycodendrimers selectively extract Cu(II) ions from the bioenvironment, while these complexes interact with the liposome surface, preferentially with even more negatively charged liposomes. However, these complexes are not able to cross the cell membrane model and poorly perturb the membrane structure, showing their potential for biomedical use.

Retinol Has a Skin Dehydrating Effect That Can Be Improved by a Mixture of Water-Soluble Polysaccharides

It is common that retinoids used in skincare can cause skin dryness, irritation and redness which is a complaint for the use of these molecules in skincare formulations. Objective: to investigate the influence of a mixture of polysaccharides to improve retinol-based formulations in a 12-day inner volar forearm study. Methods: in total, 22 inner volar forearms were treated over a 12-day topical application of a Placebo formulation containing 0.5% retinol verses a formulation containing 0.5% retinol and 3.0% of a complex of polysaccharides. Application occurred 2X/day in the morning and evening. Skin testing included barrier disruption, erythema, and skin hydration. After a 3-day regression of treatment, skin hydration was measured again. Results: the 0.5% retinol Placebo formulation showed a significant impact on skin dehydration compared to untreated control or polysaccharide-treated areas. The formulation containing retinol and 3.0% of the polysaccharides, maintained skin hydration levels comparable to the untreated control. Neither formulation had a statistically significant impact on skin erythema or barrier disruption. After the 3-day regression, the polysaccharide mixture continued to demonstrate significant moisturization benefits superior to the untreated and active-treated sites. Conclusions: a mixture of polysaccharides was able to mitigate the short-term skin drying effects of retinol and continued to moisturize the skin after a 3-Day regression.

Improved epoxy thermosets by the use of poly(ethyleneimine) derivatives

Epoxy resins are commonly used as thermosetting materials due to their excellent mechanical properties, high adhesion to many substrates and good heat and chemical resistances. This type of thermosets is intensively used in a wide range of fields, where they act as fiber-reinforced materials, general-purpose adhesives, high-performance coatings and encapsulating materials. These materials are formed by the chemical reaction of multifunctional epoxy monomers forming a polymer network produced through an irreversible way. In this article the improvement of the characteristics of epoxy thermosets using different hyperbranched poly(ethyleneimine) (PEI) derivatives will be explained.

Change in size, morphology and stability of DNA polyplexes with hyperbranched poly(ethyleneimines) containing bulky maltose units

Polyplexes between Salmon DNA and non-modified hyperbranched poly(ethyleneimines) of varying molar mass, i.e., PEI(5 k) with 5000 g/mol and PEI(25 k) with 25,000 g/mol, and modified PEI(5 k) with maltose units (PEI-Mal) were investigated in dependence on the molar N/P ratio by using dynamic light scattering (DLS), zeta potential measurements, micro differential scanning calorimetry (μ-DSC), scanning-transmission electron microscopy (STEM), and cryo-scanning electron microscopy (cryo-SEM). A reloading of the polyplexes can be observed by adding the unmodified PEI samples of different molar mass. In excess of PEI a morphological transition from core-shell particles (at N/P 8) to loosely packed onion-like polyplexes (at N/P 40) is observed. The shift of the DSC melting peak from 88 °C to 76 °C indicates a destabilization of the DNA double helix due to the complexation with the unmodified PEI. Experiments with the maltose-modified PEI show a reloading already at a lower N/P ratio. Due to the presence of the sugar units in the periphery of the polycation electrostatic interactions between DNA become weaker, but cooperative H-bonding forces are reinforced. The resulting less-toxic, more compact polyplexes in excess of the PEI-Mal with two melting points and well distributed DNA segments are of special interest for extended gene delivery experiments.