Silver Salt Enabled H/D Exchange at β Position of Thiophene Rings: Synthesis of Fully Deuterated Thiophene derivatives

We disclose a silver catalyzed H/D exchange reaction, which can introduce deuterium atom at β position of thiophene rings without the assisstance of any coordinating groups. The advantages of this...

Local hemostatic drug application for prophylaxis of pacemaker pocket hematoma

BACKGROUND: Prevention of pacemaker pocket hematoma is an urgent problem of modern cardiovascular surgery. A method of prevention of hematomas may be application of local hemostatic agents. One of such means is incomplete silver salt of polyacrylic acid, registered in the Russian Federation as a medical product under the trade name “Hemoblock”. AIM: To evaluate the efficacy and safety of partial silver salt of polyacrylic acid (Hemoblock®) as a hemostatic drug for prophylaxis of pacemaker (PM) pocket hematoma. MATERIALS AND METHODS: The study included 29 patients (18 men) with average age of 72.8 ± 9.8 years and indications for PM implantation. The patients were divided into 2 groups, partial silver salt of polyacrylic acid was used during the PM implantation in group A, 0.9% NaCl solution was used in group B. Anticoagulant therapy was not cancelled. In the postoperative period, patients underwent a daily examination by a surgeon, on the 3th–5th day — an ultrasound of soft tissues in the area of the PM pocket to diagnose hemorrhagic complications. After 1 month, a control examination of the postoperative wound and an assessment of the PM function were performed. RESULTS: In 1 (6.3%) patient in group B, a PM pocket hematoma was found which required drainage in the dressing room and increased the period of hospitalization after surgery to 7 days. Soft tissue imbibition with blood was observed in 9 (56.3%) group B patients. No PM pocket hematomas and imbibition of soft tissues were observed in group A. PM implantation with uninterrupted anticoagulant therapy without the use of hemostatic agents increases the risk of soft tissue imbibition with blood by 2.3 times (p = 0.001, r = 0.605, RR 2.3, 95% CI 1.3–4). Age, gender, body mass index, body surface area, left ventricular ejection fraction, type of anticoagulation therapy, indication for PM implantation, type of PM, and the peculiarities of the operation did not influence the risk of development of PM pocket hematoma or soft tissue imbibition with blood (p > 0.05). CONCLUSION: The use of a partial silver salt of polyacrylic acid (Hemoblock®) can reduce the risk of development of hematomas and soft tissue imbibition with blood in the area of the pacemaker pocket and does not lead to the development of infectious complications and allergic reactions.

The Procoagulant Activity of Emoxilane®: A New Appealing Therapeutic Use in Epistaxis of the Combination of Sodium Hyaluronate, Silver Salt, α-tocopherol and D-panthenol

Epistaxis is one of the most frequent hemorrhages resulting from local or systemic factors. Its management without hospitalization has prompted an interest in locally applied hemostatic agents. Generally, the therapy approaches involve sprays or creams acting as a physical barrier, even used as tampons or gauze. In this study, we have investigated the activity of Emoxilane®, a combination of sodium hyaluronate, silver salt, α-tocopherol acetate and D-panthenol, which is known to be able to separately act in a different biological manner. Our in vitro results, obtained on endothelial and nasal epithelial cells, have shown that the association of these molecules presented a notable antioxidant activity mainly due to the α-tocopherol and D-panthenol and a significant antimicrobial role thanks to the silver compound. Moreover, remarkable hemostatic activity was found by evaluating plasmin inhibition attributable to the sodium hyaluronate. Interestingly, on human plasma, we have confirmed that Emoxilane® strongly induced the increase of thrombin levels. These data suggest that the use of this association could represent an appealing pharmacological approach to actively induce hemostasis during epistaxis. Our future perspective will aim to the creation of a formulation for an easy topical application in the nose which is able to contrast the bleeding.

Sintering-Based In-Situ Synthesis and Characterization by TEM of Noble Metal Nanoparticles for Ceramic Glaze Color Control

Gold and silver salt mixtures are incorporated in ceramic glazes for in situ development of mixtures of gold and silver nanoparticles (NPs) that subsequently allow for a wide spectrum of low metal loading color control within ceramic materials. Prior work has shown that gold NPs can be used to create vibrant, color-rich red pigments in high-temperature ceramic and glass applications, though the achievable diameter of the gold NP ultimately limits the available range of color. The current study significantly expands color control from traditional gold nanoparticle red through silver nanoparticle green via the alteration of gold-to-silver salt ratios incorporated in the glaze formulations prior to sintering. Nanoparticle-based coloring systems are tested in both oxidative and reductive firing atmospheres. While the oxidation environment is found to be prohibitive for silver NP stability, the reductive atmosphere is able to form and sustain mixtures of gold and silver NPs across a wide color spectrum. All glazes are analyzed via reflectance spectrometry for color performance and samples are characterized via TEM and EDS for composition and sizing trends. This study creates new groundwork for a color-controlled NP system based on noble metal ratio blends that are both nontoxic and achieved with radically lower metal pigment loading than traditional glazes.

The Manufacture and Characterization of Silver Diammine Fluoride and Silver Salt Crosslinked Nanocrystalline Cellulose Films as Novel Antibacterial Materials

There is an unmet need for biocompatible, anti-infective, and mechanically strong hydrogels. This study investigated the use of poly vinyl alcohol (PVA), polysaccharides, and nanocrystalline cellulose (CNC) to deliver silver in a controlled manner for possible use against oral or wound bacteria. Silver was included in solvent cast films as silver diammine fluoride (SDF) or as nitrate, sulphate, or acetate salts. Hydrogel formation was assessed by swelling determinations and silver release was measured using inductively coupled plasma methods. Antibacterial studies were performed using Gram-positive and negative bacteria turbidity assays. PVA formed homogenous, strong films with SDF and swelled gently (99% hydrolyzed) or vigorously with dissolution (88% hydrolyzed) and released silver slowly or quickly, respectively. CNC-SDF films swelled over a week and formed robust hydrogels whereas CNC alone (no silver) disintegrated after two days. SDF loaded CNC films released silver slowly over 9 days whereas films crosslinked with silver salts were less robust and swelled and released silver more quickly. All silver loaded films showed good antibacterial activity. CNC may be crosslinked with silver in the form of SDF (or any soluble silver salt) to form a robust hydrogel suitable for dental use such as for exposed periodontal debridement areas.

Reception of textiles with antibacterial properties by stilbene dye usage

The possibility of imparting an antibacterial effect to cellulose tissue dyed with the product of azo coupling of diazotized 4,4’-diaminostilbene-2,2’-disulfonic acid with 8-hydroxyquinoline has been shown. It was found that fabrics dyed by fixing the dye with a silver salt have a significant antibacterial effect, which lasts at least 10 washings.