Cell-Inspired Hydrogel Microcapsules with a Thin Oil Layer for Enhanced Retention of Highly Reactive Antioxidants.

In nature, individual cells are compartmentalized by a membrane that protects the cellular elements from the surrounding environment while simultaneously equipped with an antioxidant defense system to alleviate the oxidative stress resulting from light, oxygen, moisture, and temperature. However, this mechanism has not been realized in cellular mimics to effectively encapsulate and retain highly reactive antioxidants. Here, we report cell-inspired hydrogel microcapsules with an interstitial oil layer prepared by utilizing triple emulsion drops as templates to achieve enhanced retention of antioxidants. We employ ionic gelation for the hydrogel shell to prevent exposure of the encapsulated antioxidants to free radicals typically generated during photopolymerization. The interstitial oil layer in the microcapsule serves as an stimulus-responsive diffusion barrier, enabling efficient encapsulation and retention of antioxidants by providing an adequate pH microenvironment until osmotic pressure is applied to release the cargo on-demand. Moreover, addition of a lipophilic reducing agent in the oil layer induces a complementary reaction with the antioxidant, similar to the nonenzymatic antioxidant defense system in cells, leading to enhanced retention of the antioxidant activity. Furthermore, we show the complete recovery and even further enhancement in antioxidant activity by lowering the storage temperature, which decreases the oxidation rate while retaining the complementary reaction with the lipophilic reducing agent.

Phytoglycoprotein isolated from Dioscorea batatas Decne promotes intestinal epithelial wound healing.

Dioscorea batatas Decne (DBD) has been used to heal various illnesses of the kidney and intestine as an herbal medicine in Asia. As a source of therapeutic agents, many glycoproteins have been isolated from mushrooms and plants, but the functional role of glycoprotein in intestinal epithelial wound healing has not been understood yet. In the present study, we investigated the wound healing potentials of the 30 kDa glycoprotein (DBD glycoprotein) isolated from DBD in human intestinal epithelial (INT-407) cells. We found that DBD glycoprotein (100 µg·mL-1) significantly increased the motility of INT-407 cells for 24 h by activating protein kinase C (PKC). DBD glycoprotein stimulated the activation of p38 mitogen-activated protein kinase (MAPK), which is responsible for the phosphorylation of NF-κB inhibitor α (IκBα). DBD glycoprotein increased the level of profilin-1 (PFN1), α-actinin and F-actin expression via activation of transcription factor, nuclear factor-kappa B (NF-κB) during its promotion of cell migration. Experimental mouse colitis was induced by adding dextran sulfate sodium (DSS) to the drinking water at a concentration of 4% (W/V) for 7 days. We figured out that administration of DBD glycoprotein (10 and 20 mg·kg-1) lowers the levels of disease activity index and histological inflammation in DSS-treated ICR mice. In this regard, we suggest that DBD glycoprotein has ability to promote the F-actin-related migration signaling events via activation of PKC and NF-κB in intestinal epithelial cells and prevent inflammatory bowel disease.

Nanospheres Loaded with Curcumin Improve the Bioactivity of Umbilical Cord Blood-Mesenchymal Stem Cells via c-Src Activation During the Skin Wound Healing Process.

Curcumin, a hydrophobic polyphenol derived from turmeric, has been used a food additive and as a herbal medicine for the treatment of various diseases, but the clinical application of curcumin is restricted by its poor aqueous solubility and its low permeability and bioavailability levels. In the present study, we investigate the functional role of a nanosphere loaded with curcumin (CN) in the promotion of the motility of human mesenchymal stem cells (MSCs) during the skin wound healing process. CN significantly increased the motility of umbilical cord blood (UCB)-MSCs and showed 10000-fold greater migration efficacy than curcumin. CN stimulated the phosphorylation of c-Src and protein kinase C which are responsible for the distinctive activation of the MAPKs. Interestingly, CN significantly induced the expression levels of α-actinin-1, profilin-1 and filamentous-actin, as regulated by the phosphorylation of nuclear factor-kappa B during its promotion of cell migration. In a mouse skin excisional wound model, we found that transplantation of UCB-MSCs pre-treated with CN enhanced wound closure, granulation, and re-epithelialization at mouse skin wound sites. These results indicate that CN is a functional agent that promotes the mobilization of UCB-MSCs for cutaneous wound repair.

Antioxidant and immunomodulating activities of exo-and endopolysaccharide fractions from submerged mycelia cultures of culinary-medicinal mushrooms.

A number of mushrooms are known to possess pharmacological activities. In this study, the phenolic and flavonoid contents of extracts of exo- and endopolysaccharide fractions obtained from submerged mycelia cultures of 7 edible or medicinal mushroom species, as well as their antioxidant and immunomodulatory properties, were evaluated. The exo- and endopolysaccharide yields were 0.576-1.950 and 0.438-0.933 g/L, respectively. The sugar and protein contents of these fractions were analyzed and contained predominantly sugars (52.3-87.6%). The exo- and endopolysaccharide fractions contained appreciable amounts of phenolics and flavonoids. The highest flavonoid contents were found in Cryptosporus volvatus (349.6 mg/g), followed by Cordyceps militaris (312.6 mg/g). The antioxidant activities were evaluated by 4 assays: biological assay using Saccharomyces cerevisiae, DPPH radical scavenging activity, chelating ability for ferrous ions and ferric reducing antioxidant power. The mycelia polysaccharide fractions had more ferric reducing antioxidant power than other antioxidant activities. Both exo- and endo polysaccharides of C. volvatus inhibited production of the T lymphocyte Th1 cytokines interferon (IFN)-γ and interleukin (IL)-2, the Th2 cytokines IL-4 and IL-5, and macrophage enzyme activity. Although those from C. militaris had similar inhibitory effects on cytokine production, the exopolysaccharides stimulated macrophage enzyme activity. The other exopolysaccharides (Pleurotus citrinopileatus, P. australis, and P. pulmonarius) inhibited IFN-γ and IL-5 production, but they had varying effects on IL-2 and IL-4 production. Only 3 exopolysaccharides (P. pulmonarius, Tremella mesenterica, and Cordyceps sinensis) also stimulated macrophage enzyme activity to the same extent as lipopolysaccharides. All of them reduced IL-5 production, but those from T. mesenterica also inhibited IFN-γ, IL-2, and IL-4 production. Thus the polysaccharide fractions from the mushrooms studied have antioxidant activities and general immunomodulating effects in vitro.