Improved synthesis of hyaluronic acid hydrogel and its effect on tissue augmentation.

HA-HMDA hydrogels were developed by direct amide bond formation between the carboxyl groups of hyaluronic acid (HA) and hexamethylenediamine (HMDA) with an optimized carboxyl group modification in the preliminary experiment. However, these HA-HMDA hydrogels transformed into an unstable liquid form after steam sterilization, and were problematic for application to actual dermal filler. A new method to overcome the problem of the previously developed HA-HMDA hydrogels is to prepare them by adjusting the pH in this study. Not only are these improved HA-HMDA hydrogels prepared with lower amounts of cross-linking and activation agents compared to the previously developed hydrogels, but they also maintain a stable form after steam sterilization. These improved HA-HMDA hydrogels showed higher viscoelasticity and longer lasting effects than the previous ones, despite the fact that the amount of the HMDA used as a cross-linking agent as well as 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole monohydrated (HOBt) used as activation agents were substantially reduced. According to an in vivo test using a wrinkled mouse model, the improved HA-HMDA hydrogels exhibited significantly improved tissue augmentation effects compared to a positive control of Restylane, which is widely used for the tissue augmentation throughout the world. Furthermore, histological analysis revealed excellent biocompatibility and safety of the improved synthesized HA-HMDA hydrogels.

The effect of quercetin-3-O-ß-D-glucuronopyranoside on indomethacin-induced gastric damage in rats via induction of mucus secretion and down-regulation of ICAM-1 expression.

The mechanism of the protective effect of quercetin-3-O-ß-D-glucuronopyranoside (QGC) from the leaves of Rumex aqauticus on indomethacin (IND, a representative NSAID)-induced gastric damage in rats was investigated. Pre-treatment with QGC significantly attenuated IND-induced gastric mucosal injury. An increase in myeloperoxidase (MPO) activity and expression of intercellular adhesion molecule (ICAM)-1 protein and mRNA expression of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1ß, as well as a decrease in gastric mucus secretion were detected in the gastric mucosa of IND-treated rats. QGC reversed the side effect of IND on MPO activity and mucus production. Furthermore, QGC pre-treatment notably decreased ICAM-1 protein and mRNA expression of the pro-inflammatory cytokines, suggesting that QGC protection from IND-induced damage is associated with increased gastric mucus secretion, inhibition of free radical production by activated neutrophils via ICAM-1, and pro-inflammatory cytokine downregulation.

Lysophosphatidic acid presynaptically blocks NO uptake during electric field stimulation-induced relaxation via LPA(1) receptor in cat lower esophageal sphincter.

Lysophosphatidic acid (LPA) is a lipid mediator that is involved in many biological responses, such as, in the stimulation/inhibition of proliferation, in cell migration, antiapoptosis, tumor cell invasion, platelet aggregation, vascular remodeling, and neurotransmitter release. In addition, LPA indirectly enhances the contractility of smooth muscle. Furthermore, electric field stimulation (EFS) causes contractions of isolated cat esophageal smooth muscle and relaxations of isolated cat lower esophageal sphincter (LES). To test whether or not LPA enhances postsynaptically-mediated contraction in cat esophageal smooth muscle and LES, both types of muscle strips were stimulated with muscarinic agonists. However, no significant effects were observed, and therefore, to investigate whether LPA is involved in presynaptic signal transduction, cat esophageal smooth muscle and LES were pretreated with LPA and stimulated using EFS. LPA had no effect on EFS-induced contraction in esophageal smooth muscle but the EFS-induced LES relaxation was dose-dependently inhibited by LPA. To identify the LPA receptor subtype that inhibits EFS-induced LES relaxation, we used the specific LPA(1)/LPA(3) antagonist Ki16425 and the LPA(3) agonist OMPT. Ki16425 significantly blocked the inhibitory effect of LPA on EFS-induced relaxation, but OMPT did not enhance the effect of LPA. These results suggest that LPA inhibits EFS-induced relaxation in LES via LPA(1) receptor-mediated signaling. It is well known that EFS-induced LES relaxation is related to the release of neurotransmitters, such as, nitric oxide, vasoactive intestinal polypeptide, and calcitonin gene-related peptide. We then investigated whether LPA selectively blocks NO-mediated signaling. Sodium nitroprusside-induced LES relaxation was found to be inhibited in the same manner as EFS-induced LES relaxation by LPA. This result suggests that LPA partially blocks NO uptake by presynaptic pathways, and thus, inhibits LES relaxation.

Intestinal Absorption of Fibrinolytic and Proteolytic Lumbrokinase Extracted from Earthworm, Eisenia andrei.

To investigate the intestinal absorption of a fibrinolytic and proteolytic lumbrokinase extracted from Eisenia andrei, we used rat everted gut sacs and an in situ closed-loop recirculation method. We extracted lumbrokinase from Eisenia andrei, and then raised polyclonal antibody against lumbrokinase. Fibrinolytic activity and proteolytic activity in the serosal side of rat everted gut sacs incubated with lumbrokinase showed dose- and time-dependent patterns. Immunological results obtained by western blotting serosal side solution using rat everted gut sacs method showed that lumbrokinase proteins between 33.6 and 54.7 kDa are absorbed mostly by the intestinal epithelium. Furthermore, MALDI-TOF mass spectrometric analysis of plasma fractions obtained by in situ recirculation method confirmed that lumbrokinase F1 is absorbed into blood. These results support the notion that lumbrokinase can be absorbed from mucosal lumen into blood by oral administration.