PEG-PLGA nanoparticles for encapsulating ciprofloxacin.

Antibiotic medications have been found to hinder the success of regenerative endodontic treatment due to the rapid degradation of the drug, and the acidic nature of ciprofloxacin (CIP) can be harmful to stem cells of the apical papilla (SCAPs), the cells responsible for regeneration. In this study, a nanocarrier system was used for controlled drug release for longer drug activity and less cytotoxicity to the cells. CIP was loaded in poly (ethylene glycol) methyl ether-block-poly (lactide-co-glycolide) (PEG-PLGA) nanoparticles (NPs) with an ion-pairing agent. The NPs demonstrated a monodispersed spherical morphology with a mean diameter of 120.7 ± 0.43 nm. The encapsulation efficiency of the CIP-loaded PEG-PLGA NPs was 63.26 ± 9.24%, and the loading content was 7.75 ± 1.13%. Sustained CIP release was achieved over 168 h and confirmed with theoretical kinetic models. Enhanced NP bactericidal activity was observed against Enterococcus faecalis. Additionally, CIP-loaded PEG-PLGA NPs had a low cytotoxic effect on SCAPs. These results suggest the use of a nanocarrier system to prolong the antibiotic activity, provide a sterile environment, and prevent reinfection by the bacteria remaining in the root canal during regenerative endodontic treatment.

Fluorescence identification of arthropathic calcium pyrophosphate single crystals using alizarin red S and a xanthene dipicolylamine ZnII complex.

Calcium pyrophosphate deposition disease, previously known as pseudogout, is a type of chronic and painful joint arthropathy. Accurate identification of calcium pyrophosphate dihydrate (CPPD) single crystals is crucial for determining the best course of treatment. In this study, a two-step method involving alizarin red S (ARS) and a xanthene dipicolylamine ZnII (XDZ) complex was employed for the identification of CPPD single crystals in both triclinic and monoclinic forms using a fluorescence microscope and a microplate reader. The accurate identification method proposed in this study has the potential to advance the diagnosis and treatment of patients suffering from painful gouty arthritis.

Cotton Cellulose-Derived Hydrogel and Electrospun Fiber as Alternative Material for Wound Dressing Application.

Cotton has been recognized as a useful biomaterial over decades, and it has been widely applied in the textile industry. However, a large amount of cotton waste is generated during the manufacturing processes, but it has been considered as a low-value product. With high content of cellulose remaining in cotton waste, our study focuses on transforming cotton cellulose into a valuable product. Cellulose was extracted from cotton waste and modified into two main materials for wound dressing application: hydrogel-based water absorbent materials and electrospun composite nanofibers. In order to enhance the water absorption, carboxymethyl cellulose (CMC), the modified cellulose with functional group prone to interact with water molecules, has been developed in this study. The hydrogel-based CMC was created by using the chemical cross-linking reaction of epichlorohydrin (ECH). The hydrogel demonstrated the swelling and reswelling ability by 1718 ± 137% and 97.95 ± 9.76%, respectively. Meanwhile, cellulose/PEG in trifluoroacetic acid (TFA) was successfully fabricated as nonwoven composite by a conventional electrospinning technique. The fabrics provided highly appropriated properties as wound dressing, including the following: water absorption was up to 1300 times and water vapor permeability controlled in the range of 2163-2285 g·m-2·day-1. This showed the preliminary information for recovering cotton waste into valuable products.

Amphiphilic dextran-vinyl laurate-based nanoparticles: formation, characterization, encapsulation, and cytotoxicity on human intestinal cell line.

Dextran has been the model material for the therapeutic applications owing to its biodegradable and biocompatible properties, and the ability to be functionalized in variety of ways. In this study, the amphiphilic dextran was successfully synthesized through lipase-catalyzed transesterification between dextran and vinyl laurate. In aqueous solution, the produced dextran ester could self-assemble into spherical nanoparticles ("Dex-L NPs") with approximately 200-nm diameter, and could incorporate porcine placenta hydrolysate with 60% encapsulation efficiency. Furthermore, Dex-L NPs exhibited low cytotoxic effects on human intestinal cell line and, thus, were potentially safe for oral administration. Taken together, the findings illustrate the potential of the newly developed nanoparticles to serve as an efficient and safe drug delivery system.

Fully synthetic polymer vesicles for intracellular delivery of antibodies in live cells.

There is an emerging need both in pharmacology and within the biomedical industry to develop new tools to target intracellular mechanisms. The efficient delivery of functionally active proteins within cells is potentially a powerful research strategy, especially through the use of antibodies. In this work, we report on a nanovector for the efficient encapsulation and delivery of antibodies into live cells with no significant loss of cell viability or any deleterious effect on cell metabolic activity. This delivery system is based on poly[2-(methacryloyloxy)ethyl phosphorylcholine]-block-[2-(diisopropylamino)ethyl methacrylate] (PMPC-PDPA), a pH-sensitive diblock copolymer that self-assembles to form nanometer-sized vesicles, also known as polymersomes, at physiological pH. Polymersomes can successfully deliver relatively high antibody payloads within different types of live cells. We demonstrate that these antibodies can target their respective epitope showing immunolabeling of γ-tubulin, actin, Golgi protein, and the transcription factor NF-κB in live cells. Finally, we demonstrate that intracellular delivery of antibodies can control specific subcellular events, as well as modulate cell activity and proinflammatory processes.

Encapsulation of biomacromolecules within polymersomes by electroporation.

Biological macromolecules can be encapsulated into preformed polymersomes by controlled temporary destabilization of the vesicle membrane. The morphology and the size of the polymersome are unchanged after electroporation, suggesting that the polymersome membrane is reformed. The surface charge of the biomacromolecules plays a key role for the electroporation process.

Copper ions potentiate organic hydroperoxide and hydrogen peroxide toxicity through different mechanisms in Xanthomonas campestris pv. campestris.

Copper (Cu)-based biocides are important chemical controls for both fungal and bacterial diseases in crop fields. Here, we showed that Cu ions at a concentration of 100 µM enhanced t-butyl hydroperoxide (tBOOH) and hydrogen peroxide (H(2) O(2) ) killing of Xanthomonas campestris pv. campestris through different mechanisms. The addition of an antilipid peroxidation agent (α-tocopherol) and hydroxyl radical scavengers (glycerol and dimethyl sulphoxide) partially protected the bacteria from the Cu-enhanced tBOOH and H(2) O(2) killing, respectively. Inactivation of the alkyl hydroperoxide reductase gene rendered the mutant vulnerable to lethal doses of copper sulphate, which could be alleviated by the addition of an H(2) O(2) scavenger (pyruvate) and α-tocopherol. Taken together, the data suggest that Cu ions influence the killing effect of tBOOH through the stimulation of lipid peroxidation, while hydroxyl radical production is the underlying mechanism responsible for the Cu-ion-enhanced H(2) O(2) killing effects.