A Minimalist Method for Fully Oxygen-Tolerant RAFT Polymerization through Sulfur-Centered Trithiocarbonate Radical Initiation.

In recent years, the fully oxygen-tolerant reversible deactivation radical polymerization (RDRP) has become a highly researched area. In this contribution, a new and minimalist method is successfully employed to accomplish fully oxygen-tolerant reversible addition-fragmentation chain transfer (RAFT) polymerization using bis(trithiocarbonate) disulfides (BisTTC) as an iniferter agent, where the released sulfur-centered trithiocarbonate (TTC) radical can initiate monomer. Furthermore, polymerization kinetics revealed the typical "living" features of this polymerization system. More importantly, by high-throughput screening, it is found that dodecyl-substituted TTC is responsible for the fully oxygen-tolerant RAFT polymerization though trithiocarbonate radical initiation and R radical deoxygenation. It is believed that trithiocarbonate radical initiation strategy provides a powerful and minimalist tool for fully oxygen-tolerant RDRPs.

Using the yeast vacuole as a system to test the lipidic drivers of membrane heterogeneity in living cells.

The biophysical drivers of membrane lateral heterogeneity, often termed lipid rafts, have been largely explored using synthetic liposomes or mammalian plasma membrane-derived giant vesicles. Yeast vacuoles, an organelle comparable to mammalian lysosomes, is the only in vivo system that shows stable micrometer scale phase separation in unperturbed cells. The ease of manipulating lipid metabolism in yeast makes this a powerful system for identifying lipids involved in the onset of vacuole membrane heterogeneity. Vacuole domains are induced by stationary stage growth and nutritional starvation, during which they serve as a docking and internalization site for lipid droplet energy stores. Here we describe methods for characterizing vacuole phase separation, its physiological function, and its lipidic drivers. First, we detail methodologies for robustly inducing vacuole domain formation and quantitatively characterizing during live cell imaging experiments. Second, we detail a new protocol for biochemical isolation of stationary stage vacuoles, which allows for lipidomic dissection of membrane phase separation. Third, we describe biochemical techniques for analyzing lipid droplet internalization in vacuole domains. When combined with genetic or chemical perturbations to lipid metabolism, these methods allow for systematic dissection of lipid composition in the structure and function of ordered membrane domains in living cells.

Tuning the Mechanical Properties of 3D-printed Objects by Mixing Chain Transfer Agents in Norrish Type I Photoinitiated RAFT Polymerization.

Photoinduced 3D printing via photocontrolled reversible-deactivation radical polymerization (photoRDRP) techniques has emerged as a robust technique for creating polymeric materials. However, methods for precisely adjusting the mechanical properties of these materials remain limited. In this study, we present a facile approach for adjusting the mechanical properties of 3D-printed objects by adjusting the polymer dispersity within a Norrish type I photoinitiated reversible addition-fragmentation chain transfer (NTI-RAFT) polymerization-based 3D printing process. We investigated the effects of varying the concentrations and molar ratios of trithiocarbonate (BTPA) and xanthate (EXEP) on the mechanical properties of the printed materials. Our findings demonstrate that increased concentrations of RAFT agents or higher proportions of the more active BTPA lead to a decrease in Young's modulus and glass transition temperatures, along with an increase in elongation at break, which can be attributed to the enhanced homogeneity of the polymer network. Using a commercial LCD printer, the NTI-RAFT-based 3D printing system effectively produced materials with tailored mechanical properties, highlighting its potential for practical applications.

Automated cardiac vortex ring identification and characterization based on Recurrent All-Pairs Field Transforms and Lagrangian Averaged Vorticity Deviation.

Automated identification of cardiac vortices is a formidable task due to the complex nature of blood flow within the heart chambers. This study proposes a novel approach that algorithmically characterizes the identification criteria of these cardiac vortices based on Lagrangian Averaged Vorticity Deviation (LAVD). For this purpose, the Recurrent All-Pairs Field Transforms (RAFT) is employed to assess the optical flow over the Phase Contrast Magnetic Resonance Imaging (PC-MRI), and to construct a continuous blood flow velocity field and reduce errors that arise from the integral process of LAVD. Additionally, Generalized Hough Transform (GHT) is applied for automated depiction of the structure of cardiac vortices. The effectiveness of this method is demonstrated and validated by the computation of the acquired cardiac flow data. The results of this comprehensive visual and analytical study show that the evolution of cardiac vortices can be effectively described and displayed, and the RAFT framework for optical flow can synthesize the in-between PC-MRIs with high accuracy. This allows cardiologists to acquire a deeper understanding of intracardiac hemodynamics and its impact on cardiac functional performance.

The bio-larvicide Bacillus thuringiensis var. israelensis is effective against Aedes koreicus, either dissolved in water or delivered through eco-compatible chitosan-based hydrogels.

Mosquito control, which is not always easily accomplished, is further complicated by the spread of invasive species. This is the case of Aedes koreicus, a mosquito native to East Asia, whose presence has been recorded in several European countries, including Italy. This mosquito found suitable ecological conditions in central Europe in general, and in northern Italy in particular, as shown by the ongoing expansion of its distribution. While basic knowledge on feeding habits of Ae. koreicus have already been acquired, information on its vectorial competence is scarce. Therefore, active monitoring on the presence of this mosquito, and the pre-planning of future control actions, are of paramount importance. Currently, there are no specific guidelines for controlling this mosquito, both in its native regions and in invaded countries. Here we present the first study on the efficacy of a bioinsecticide based on Bacillus thuringiensis on Ae. koreicus larvae, with a comparison with results obtained on the tiger mosquito Aedes albopictus. Our results proved that this bioinsecticide is effective on Ae. koreicus, both dissolved in water and incorporated into MosChito raft, a hydrogel-based matrix that has recently been developed for the delivery of insecticides to other mosquito species and suitable for safe and eco-compatible applications.

Oral co-polymeric raft-forming nano gels for targeted empagliflozin delivery against stomach cancer (SGC7901).

Empagliflozin (EMP) is known for its poor safety and efficacy profile due to its fast body distribution and poor solubility. Accordingly, an oral long-acting and floating/raft-forming nano gel was optimized to release coated EMP nanoparticles, and the released EMP nanoparticles showed enhanced dissolution compared to raw EMP particles. To repurpose EMP for cancer treatment, EMP shows anti-cancer and anti-inflammatory effects against cancer cells. EMP nanoparticles were characterized using FT-IR, PXRD, SEM, EMP encapsulation assay, and release studies. The raft-forming gel encapsulating the EMP was optimized and characterized. The EMP co-polymeric nanoparticles were studied to investigate EMP anti-cancer and anti-inflammatory activities against stomach cancer cells. The solubility of EMP nanoparticles was enhanced in 0.1 N HCl and pH 6.8 by 5 and 12 folds, respectively, compared to raw EMP powder. The particle size and zeta-potential values of improved EMP nanoparticles were 135.40 ± 18.60 nm, and -19.30 ± 0.80 mV, respectively. FT-IR, PXRD, SEM and TEM characterizations revealed polymeric coating of EMP particles. The study suggested that this optimized controlled-release raft-forming gel is a promising local oral approach against stomach cancer. The repurposing of EMP co-polymeric nanoparticles for stomach cancer and associated gastritis treatment was justified.

Terpyridine-Decorated Polymer Nanosphere Latex: Template Nanocarriers for the Synthesis of Cu-CeO2 Hollow Spheres.

Water-soluble polymers with the ability to complex metal ions through complexing ligands have attracted significant interest in diverse domains, such as optical or catalyst applications. In this paper, we successfully synthesized, through a one-pot process combining polymerization-induced self-assembly and reversible addition-fragmentation chain transfer polymerization, aqueous dispersions of terpyridine-decorated poly[poly(ethylene glycol)methyl ether methacrylate]-b-poly(methyl methacrylate) (tpy-PPEGMA-b-PMMA) amphiphilic block copolymers. The in-situ formation of well-defined amphiphilic block copolymers and their self-assembly led to nanosphere latex with the hydrodynamic diameters increasing from 17 to 52 nm and the length of the copolymers increasing from 21,000 to 51,000 g·mol-1. These aqueous dispersed tpy-PPEGMA-b-PMMA nanospheres effectively complex metal ions, such as Cu2+, in a stoichiometric ratio of 2:1. Subsequently, these metal-complexed nanospheres were employed as soft template nanocarriers to control, on the nanometer scale, the dispersion of metal on a nanostructured support. This is exemplified by the synthesis of copper supported on cerium oxide hollow spheres (Cu-CeO2) using Cu2+-tpy-PPEGMA-b-PMMA as template nanocarriers and CeO2 nanoparticles. This novel assembly engineering strategy for the preparation of atomically dispersed metal on a nanostructured support was highlighted through the utilization of Cu-CeO2 hollow spheres as an electrocatalyst for the nitrate reduction reaction (NO3RR) to NH3. These encouraging outcomes emphasize the potential of metal-metal oxide-nanostructured materials to treat contaminated water sources with nitrate while allowing the green production of ammonia.

Design and Preparation of Lifetime-Based Dual Fluorescent/Phosphorescent Sensor of pH and Oxygen and its Exploration in Model Physiological Solutions and Cells.

In the present report, a novel dual pH-O2 sensor based on covalent conjugate of rhodamine 6G and cyclometalated iridium complex with poly(vinylpyrrolidone-block-vinyltetrazole) copolymer is reported. In model physiological solutions the sensor chromophores display independent phosphorescent and fluorescent lifetime responses onto variations in oxygen concentration and pH, respectively. Colocalization studies on Chinese hamster ovary cells demonstrate the preferential localization in endosomes and lysosomes. The fluorescent lifetime imaging microscopy-phosphorescent lifetime imaging microscopy (FLIM-PLIM) experiments show that the phosphorescent O2 sensor provides unambiguous information onto hypoxia versus normoxia cell status as well as semi-quantitative data on the oxygen concentration in cells in between these two states. However, the results of FLIM measurements indicate that dynamic lifetime interval of the sensor (≈0.5 ns between pH values 5.0 and 8.0) is insufficient even for qualitative estimation of pH in living cells because half-width of lifetime distribution in the studied samples is higher than the sensor dynamic interval. Nevertheless, the variations in rhodamine emission intensity are much higher and allow rough discrimination of acidic and neutral cell conditions. Thus, the results of this study indicate that the suggested approach to the design of dual pH-O2 sensors makes possible to prepare the biocompatible and water-soluble conjugate with fast cellular uptake.

Strategies for preparation of chitosan based water-soluble fluorescent probes to detect Cr3+ and Cu2+ ions.

The low solubility of chitosan (CS) imposes adverse effects on its application. In this work, one of the aims is to improve the water solubility of CS. By introducing water-soluble side chains to CS, this aim was achieved. Besides, fluorescent moieties were incorporated into the side chains, the fluorescent copolymers were endowed with Cr3+ and Cu2+ ions recognition ability. Firstly, a reversible addition-fragmentation chain transfer polymerization (RAFT) reagent with naphthalimide units and CC groups was prepared. Water-soluble monomer methyl acrylic acid (MAA) was employed in the RAFT polymerization. Thus, water-soluble polymer with fluorescent unit and -C ≡ C on both ends of the polymer was obtained. They were introduced into CS, and the CS-based fluorescent copolymers were obtained eventually. The amount of MAA introduced could be tuned to obtain three side chains of different lengths. It was found that the more MAA was introduced, the better the solubility of CS-TP was. The detection limits (LOD) of Cr3+ and Cu2+ were 44.6 nM and 54.5 nM, respectively. The detection of Cr3+ and Cu2+ ions is further combined with a mobile APP to realize real-time, portable, and visual detection. And the application in the logic gate, a new detection platform, is prepared.

Pyrene-functionalized poly(methacrylic acid) acts as an efficient stabilizer for graphene nanoplatelets and facilitates their use in waterborne latex formulations.

HYPOTHESIS: Pyrene derivatives are effective motifs when designing graphene-philic surfactants, enabling the use of hydrophobic graphene-based nanomaterials in waterborne formulations. Hence, novel pyrene end-functionalized polymeric stabilizers show promise for stabilizing aqueous graphene nanomaterial dispersions, and offer benefits over traditional small molecule surfactants. EXPERIMENTS: Pyrene end-functionalized poly(methacrylic acid) (Py-PMAAn, where n = 68 to 128) was synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization of MAA using a pyrene-containing RAFT chain-transfer agent. These polymers were evaluated as aqueous graphene nanoplatelet (GNP) stabilizers. Subsequently, polymer-stabilized GNPs were formulated into film-forming polymer latex dispersions and the properties of the resulting GNP-containing films measured. FINDINGS: Py-PMAAn homopolymers with well-defined molecular weights were prepared via RAFT solution polymerization. They served as efficient stabilizers for aqueous GNP dispersions and performed better than a traditional small molecule surfactant and non-functionalized PMAA, especially at higher pH and with higher molecular weight polymers. The use of Py-PMAAn allowed GNPs to be readily formulated into waterborne latex coatings. When compared to controls, the resulting films were significantly reinforced due to the improved homogeneity of dried nanocomposite films and chain entanglement between the polymer matrix and stabilizers. Thus, the ability to readily incorporate GNPs into aqueous formulations and enhance GNP/polymer matrix interfaces was demonstrated for these novel amphiphilic stabilizers.

Elucidation of cellular signaling mechanism involved in Vibrio cholerae chitin-binding protein GbpA mediated IL-8 secretion in the intestinal cells.

Background: Vibrio cholerae N-acetylglucosamine-binding protein (GbpA) is a four-domain, secretory colonization factor which is essential for chitin utilization in the environment, as well as in adherence to intestinal cells. GbpA is also involved in inducing intestinal inflammation by enhancing mucin and interleukin-8 secretion. The underlying cell signaling mechanism involved in the induction of the pro-inflammatory response and IL-8 secretion has yet to be deciphered in detail. Methods: Herein, the process through which GbpA triggers the induction of IL-8 in intestinal cells was investigated by examining the role of GbpA in intestinal cell line HT 29. Results: GbpA, specifically through the fourth domain, forms a binding connection with Toll-like receptor 2 (TLR2) and additionally, recruits TLR1 along with CD14 within a lipid raft micro-domain to initiate the signaling pathway. Notably, disruption of this micro-domain complex resulted in a reduction in IL-8 secretion. The lipid raft association served as the catalyst that invoked a downstream cellular inflammatory signaling pathway. This cascade involved the activation of various MAP kinases and NFκB and assembly of the AP-1 complex. This coordinated activation of signaling molecules eventually leads to enhanced IL-8 transcription via increased promoter activity. These findings suggested that GbpA is a crucial protein in V. cholerae, capable of inciting a pro-inflammatory response during infection by orchestrating the formation of the GbpA-TLR1/2-CD14 lipid raft complex. Activation of AP-1 and NFκB in the nucleus eventually enhanced IL-8 transcription through increased promoter activity. Conclusion: Collectively, these findings indicated that GbpA plays a pivotal role within V. cholerae by triggering a pro-inflammatory response during infection. This response is instrumented by the formation of the GbpA-TLR1/2-CD14 lipid raft complex.

Phase separation in model lipid membranes investigated with cryogenic electron microscopy.

We describe a method for investigating lateral membrane heterogeneity using cryogenic electron microscopy (cryo-EM) images of liposomes. The method takes advantage of differences in the thickness and molecular density of ordered and disordered phases that are resolvable in phase contrast cryo-EM. Compared to biophysical techniques like FRET or neutron scattering that yield ensemble-averaged information, cryo-EM provides direct visualization of individual vesicles and can therefore reveal variability that would otherwise be obscured by averaging. Moreover, because the contrast mechanism involves inherent properties of the lipid phases themselves, no extrinsic probes are required. We explain and discuss various complementary analyses of spatially resolved thickness and intensity measurements that enable an assessment of the membrane's phase state. The method opens a window to nanodomain structure in synthetic and biological membranes that should lead to an improved understanding of lipid raft phenomena.

Development of raft-forming liquid formulations loaded with ginger extract-solid dispersion for treatment of gastric ulceration.

Raft-forming liquid formulations incorporating ginger extract solid dispersion (GE-SD) were developed to achieve prolonged delivery of 6-gingerol in the stomach and thus increase the effectiveness of gastric ulcer treatment. The solubility of 6-gingerol in 0.1 N HCl (pH 1.2) was maximized (15 mg/mL) by combining ginger extract with PVP K30 at 1:3 w/w ratio to produce a solid dispersion. The nature of GE-SD was confirmed by PXRD and FT-IR analysis. PXRD pattern showed miscibility of GE and PVP K30 in amorphous solid dispersion and the FT-IR spectra confirmed the formation of hydrogen bond between GE and PVP K30. GE-SD-loaded raft-forming liquids were prepared using sodium alginate as a gel former and HPMC as a release-controlling agent. The formulations exhibited rapid floating behavior in 0.1 N HCl (<30 s) and remained afloat on the surface over 8 h. The formed raft structures provided sufficient strength (>7.5 g) and allowed sustained release of more than 70 % of the 6-gingerol content over 8 h in 0.1 N HCl. Raft-forming formulations incorporating ginger extract demonstrated anti-inflammatory activity by inhibiting nitric oxide production in LPS-stimulated RAW 264.7 macrophage cells (IC50 = 5.13 ± 0.07 µg/mL). Exposure to the formulations also had a significant cytotoxic effect on AGS human gastric adenocarcinoma cells with an IC50 of 17.45 ± 0.29 µg/mL. In addition, the raft-forming formulations enhanced the migratory behavior of L929 mouse fibroblasts in the scratch wound model. Taken together, these findings reveal the benefits of gastro-retentive, GE-SD-loaded raft-forming liquid formulations for improving the treatment of gastric ulcers.

Individualized lipid profile in urine-derived extracellular vesicles from clinical patients with Mycobacterium tuberculosis infections.

Background: Lipids are a key nutrient source for the growth and reproduction of Mycobacterium tuberculosis (Mtb). Urine-derived extracellular vesicles (EVs), because of its non-invasive sampling, lipid enrichment, and specific sorting character, have been recognized as a promising research target for biomarker discovery and pathogenesis elucidation in tuberculosis (TB). We aim to profile lipidome of Mtb-infected individuals, offer novel lipid signatures for the development of urine-based TB testing, and provide new insights into the lipid metabolism after Mtb infection. Methods: Urine-derived extracellular vesicles from 41 participants (including healthy, pulmonary tuberculosis, latent tuberculosis patients, and other lung disease groups) were isolated and individually detected using targeted lipidomics and proteomics technology platforms. Biomarkers were screened by multivariate and univariate statistical analysis and evaluated by SPSS software. Correlation analyses were performed on lipids and proteins using the R Hmisc package. Results: Overall, we identified 226 lipids belonging to 14 classes. Of these, 7 potential lipid biomarkers for TB and 6 for latent TB infection (LTBI) were identified, all of which were classified into diacylglycerol (DAG), monoacylglycerol (MAG), free fatty acid (FFA), and cholesteryl ester (CE). Among them, FFA (20:1) was the most promising biomarker target in diagnosing TB/LTBI from other compared groups and also have great diagnostic performance in distinguishing TB from LTBI with AUC of 0.952. In addition, enhanced lipolysis happened as early as individuals got latent Mtb infection, and ratio of raft lipids was gradually elevated along TB progression. Conclusion: This study demonstrated individualized lipid profile of urinary EVs in patients with Mtb infection, revealed novel potential lipid biomarkers for TB/LTBI diagnosis, and explored mechanisms by which EV lipid raft-dependent bio-processes might affect pathogenesis. It lays a solid foundation for the subsequent diagnosis and therapeutic intervention of TB.

2-Cyanopropan-2-yl versus 1-Cyanocyclohex-1-yl Leaving Group: Comparing Reactivities of Symmetrical Trithiocarbonates in RAFT Polymerization.

This study introduces bis(1-cyanocyclohex-1-yl)trithiocarbonate (TTC-bCCH) as a novel trithiocarbonate chain transfer agent and compares its reactivity with the previously described bis(2-cyanopropan-2-yl)trithiocarbonate (TTC-bCP) for the reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St), n-butyl acrylate (nBA), and methyl methacrylate (MMA). Significant findings include the effective control of Mn and low dispersities from the onset of polymerization of St and nBA showing swift addition-fragmentation kinetics, leading to similar behaviors between the two RAFT agents. In contrast, a fourfold decrease of the chain transfer constant to MMA is established for TTC-bCCH over TTC-bCP. This trend is confirmed through density functional theory (DFT) calculations. Finally, the study compares thermoplastic elastomer properties of all-(meth)acrylic ABA block copolymers produced with both RAFT agents. The impact of dispersity of PMMA blocks on thermomechanical properties evaluated via rheological analysis reveals a more pronounced temperature dependence of the storage modulus (G') for the triblock copolymer synthesized with TTC-bCCH, indicating potential alteration of the phase separation.

Optimizing nutrient utilization, hydraulic loading rate, and feed conversion ratios through freshwater IMTA-aquaponic and hydroponic systems as an environmentally sustainable aquaculture concept.

Water quality in land-based fish production can be controlled through either instantaneous water exchange or costly wastewater treatment followed by recirculation. Agricultural-aquaculture integration is an excellent alternative technique for reducing nutrient discharge levels, boosting profitability, and converting fish culture wastewater into valuable products. The current study employed a solar energy system to power two separate IMTA-aquaponics systems (Nutrient Film Technique, NFT, and Floating Raft Systems, FRS) for the cultivation of Nile tilapia, African catfish, thin-lipped grey mullet, freshwater crayfish, freshwater mussels, and a variety of vegetables. Tilapia and catfish were fed exclusively on diets under the IMTA system. All wastewater from tilapia and catfish ponds, both dissolved and solid, flows sequentially to ponds containing other cultivated species. The water then flows through the IMTA system's terminal point to the NFT and FRS systems before returning to the tilapia and catfish ponds, allowing complete control of the nutrient flow throughout this entire circular system. Two 147-day production cycles were concluded. The results from the second production cycle are reported. Total biomass gain for aquatic species in the IMTA system was 736.46 kg, compared to 145.49 kg in the tilapia and 271.01 kg in the catfish monoculture systems. The current IMTA system had a cumulative feed conversion ratio (FCR) of 0.90, while the FCRs for tilapia and catfish were 1.28 and 1.42, respectively. Nile tilapia and catfish consumed 571.90 kg of feed containing 25.70 kg of nitrogen (N) and 9.70 kg of phosphorus (P), reflecting, and gaining 11.41 and 3.93 kg of dietary N and P, representing 44.40 and 40.46% dietary N and P retention, respectively. In the IMTA system, the addition of mullet and prawn as detrivores aquatic animals improves dietary N and P utilization efficiency to 59.06 and 51.19%, respectively, while the addition of mussels as herbivore animals improves dietary N and P utilization efficiency to 65.61 and 54.67%, respectively. Finally, using FRS and NFT as hydroponic systems increased dietary N and P efficiency to 83.51% N and 96.82% P, respectively. This study shows that the IMTA-Aquaponic system, as a bio-integrated food production system, can convert the majority of fish-fed residues into valuable products suitable for desert, rural, and urban areas in impoverished and developing countries.

Block Copolymer Self-assembly: Exploitation of Hydrogen Bonding for Nanoparticle Morphology Control via Incorporation of Triazine Based Comonomers by RAFT Polymerization.

Synthesis of polymeric nanoparticles of controlled non-spherical morphology is of profound interest for a wide variety of potential applications. Self-assembly of amphiphilic diblock copolymers is an attractive bottom-up approach to prepare such nanoparticles. In the present work, RAFT polymerization is employed to synthesize a variety of poly(N,N-dimethylacrylamide)-b-poly[butyl acrylate-stat-GCB] copolymers, where GCB represents vinyl monomer containing triazine based Janus guanine-cytosine nucleobase motifs featuring multiple hydrogen bonding arrays. Hydrogen bonding between the hydrophobic blocks exert significant influence on the morphology of the resulting nanoparticles self-assembled in water. The Janus feature of the GCB moieties makes it possible to use a single polymer type in self-assembly, unlike previous work exploiting, e.g., thymine-containing polymer and adenine-containing polymer. Moreover, the strength of the hydrogen bonding interactions enables use of a low molar fraction of GCB units, thereby rendering it possible to use the present approach for copolymers based on common vinyl monomers for the development of advanced nanomaterials.

Synthesis of New Glycine-Based Polymers and their Thermoresponsive Behavior in Water.

In this work, new glycine-derived polymers are developed that exhibit thermoresponsive properties in water. Therefore, a series of monomers containing one, two, or three amide functional groups and one terminal cyanomethyl group is synthesized. The resulting homopolymers, obtained by free radical polymerization (FRP) and reversible addition fragmentation chain transfer (RAFT) polymerization, display a sharp and reversible upper critical solution temperature (UCST)-type phase transition in water. Additionally, it is shown that the cloud point (TCP) can be adjusted over more than 60 °C by the number of glycyl groups present in the monomer structure and by the polymer's molar mass. These novel thermoresponsive polymers based on cyanomethylglycinamide enrich the range of nonionic UCST polymers and are promising to find applications in various fields.

Polyoxometalate-Polymer Directed Macromolecular Architectonics of Silver Nanoparticles as Effective Antimicrobials.

A novel inorganic-organic-inorganic ternary bioactive material formulated on antimicrobial peptide-based polymer has been reported. Supramolecular approach has been employed to incorporate molecularly crowded tyrosine-based polymer stabilized silver nanoparticles into membrane bound vesicles exploiting polyoxometalate-triggered surface templating strategy. Utilizing the covalent reversible addition fragmentation chain transfer (RAFT) polymerization and exploiting templated supramolecular architectonics at biopolymer interface, the bioactive ternary polymeric nanohybrids have been designed against Shigellosis leveraging the antibacterial activities of silver nanoparticle, cationic amphiphilic tyrosine polymer and inorganic polyoxometalate. The detail investigation against Shigella flexneri 2a cell line demonstrates that the collaborative mechanism of the ternary hybrid composite enhances the bactericidal activity in comparison to only polyoxometalate and polymer stabilized silver nanoparticle with an altered mechanism of action which is established via detailed biological analysis.

Improved gastric residence time of famotidine by raft-forming drug delivery system using DOE.

OBJECTIVE: This study investigated the raft-forming suspension of famotidine as an anti-reflux formulation to improve the oral bioavailability of narrow absorption window drugs by enhancing gastric residence time (GRT) and preventing gastro-esophageal reflux disease (GERD). METHOD: Various combinations of raft-forming agents, such as Tragacanth gum (TG), guar gum (GG), and xanthan gum (XG), were evaluated alongside sodium alginate (SA) to develop an effective raft. Preformulation studies and preliminary screening were conducted to identify the most suitable raft-forming agent, and GG was chosen due to its mucilaginous properties. The formulation was optimized using a 32 full factorial design, with the quantities of GG and SA as independent factors and apparent viscosity and in-vitro drug release (%) as dependent factors. The in vivo floating behavior study was performed for optimized and stabilized formulation. RESULTS: Among the tested batches, F6 was selected as the optimized formulation. It exhibited desirable characteristics such as adequate raft weight for extended floating in gastric fluid, improved apparent viscosity, and a significant percentage of drug release at 12 h. A mathematical model was applied to the in-vitro data to gain insights into the drug release mechanism of the formulation. The stability of the suspension was assessed under accelerated conditions, and it demonstrated satisfactory stability. The formulation remains floating in the Rabbit stomach for more than 12 h. CONCLUSION: It concludes that the developed formulation has enhanced bioavailability in the combination of GG and SA. The floating layer of the raft prevents acid reflux, and the famotidine is retained for an extended period of time in the gastric region, preventing excess acid secretion. The developed formulations are effective for stomach ulcers and GERD, with the effect of reducing acid secretion by H2 receptor antagonists.