Sodium Bis 2-ethylhexyl Sulfosuccinate Research Articles

Synthesis of PDMS Chain Structure with Introduced Dynamic Covalent Bonding for High‐Performance Rehealable Tactile Sensor Application

AbstractIn addressing the increasing demand for wearable sensing systems, the performance and lifespan of such devices must be improved by enhancing their sensitivity and healing capabilities. The present work introduces an innovative method for synthesizing a healable disulfide bond contained in a polydimethylsiloxane network (PDMS−SS) that incorporates ionic salts, which is designed to serve as a highly effective dielectric layer for capacitive tactile sensors. Within the polymer network structure, the cross‐linking agent pentaerythritol tetrakis 3‐mercaptopropionate (PTKPM) forms reversible disulfide bonds while simultaneously increasing polymer softness and the dielectric constant. The incorporation of dioctyl sulfosuccinate sodium salt (DOSS) significantly improves the capacitance and sensing properties by forming an electrical double‐layer through interactions between the electrode charge and salt ions at the contact interface. The developed polymer material‐based tactile sensor shows a strong response signal at low pressure (0.1 kPa) and maintains high sensitivity (0.175 kPa−1) over a wide pressure range (0.1–10 kPa). It also maintains the same sensitivity over 10 000 repeated applications of external pressure and is easily self‐healed against mechanical deformation due to the dynamic disulfide covalent bonding, restoring ≈95% of its detection capacity.

Combined application of surfactants and iron-based metal–organic framework nanoparticles for targeted delivery of insecticides

With the development of smart delivery systems for pesticides, many studies revealed that nanodelivery methods have great potential for use in efficient and sustainable agriculture; however, field application of the nanopesticides is still a challenge. In this study, the application of a chlorfenapyr (CF)-loaded iron-based metal–organic framework (CF@MIL-101-SL) to maize and its control efficacy for Spodoptera frugiperda were investigated in detail. The results showed that, compared with a suspension concentrate of CF (CF-SC), a solution of CF@MIL-101-SL with the surfactant aerosol OT exhibited excellent wetting, deposition and adhesion with maize leaves. The CF@MIL-101-SL NPs exhibited bidirectional translocation in maize, which significantly enhanced the transport of CF to the target tissues. Field trials revealed that CF@MIL-101-SL maintained > 75 % control efficiency after 21 d of spraying, indicating significantly greater insecticidal activity and persistence than CF-SC. Spray application of CF@MIL-101-SL gave high initial deposition rates, long half-lives on tender and old leaves and significantly reduced pesticide drift into the environment. Based on a biosafety assessment, spraying with CF@MIL-101-SL reduced the negative effects of CF on plants during the growth period. In addition, CF@MIL-101-SL increased the survival rate of Harmonia axyridis larvae and reduced the impacts of CF on the growth and intestinal damage of Harmonia axyridis. In summary, these results highlight the advantages of metal–organic framework delivery systems for multidimensional enhancement of pesticide efficacy, persistence, and safety and provide data on field application and the environmental risks of nanodelivery systems.

Detergent-induced quantitatively limited formation of diacyl phosphatidylinositol dimannoside in Mycobacterium smegmatis

Mycobacterial plasma membrane, together with the peptidoglycan-arabinogalactan cell wall and waxy outer membrane, creates a robust permeability barrier against xenobiotics. The fact that several antituberculosis drugs target plasma membrane-embedded enzymes underscores the importance of the plasma membrane in bacterial physiology and pathogenesis. Nevertheless, its accurate phospholipid composition remains undefined, with conflicting reports on the abundance of phosphatidylinositol mannosides (PIMs), physiologically important glycolipids evolutionarily conserved among mycobacteria and related bacteria. Some studies indicate cardiolipin, phosphatidylethanolamine, and phosphatidylinositol as dominant structural phospholipids. Conversely, some suggest PIMs dominate the plasma membrane. A striking example of the latter is the use of reverse micelle extraction, showing diacyl phosphatidylinositol dimannoside (Ac2PIM2) as the most abundant phospholipid in a model organism, Mycobacterium smegmatis. Our recent work reveals a rapid response mechanism to membrane-fluidizing stress in mycobacterial plasma membrane: monoacyl phosphatidylinositol dimannoside and hexamannoside (AcPIM2 and AcPIM6) are converted to diacyl forms (Ac2PIM2 and Ac2PIM6). Given the dynamic nature of PIMs, we aimed to resolve the conflicting data in the literature. We show that unstressed M. smegmatis lacks an Ac2PIM2-dominated plasma membrane. Ac2PIM2 accumulation is induced by experimental conditions involving sodium docusate, a component of the reverse micellar solution. Using chemically synthesized PIMs as standards, we accurately quantified phospholipid ratio in M. smegmatis through liquid chromatography-mass spectrometry, revealing that mycobacterial plasma membrane is dominated by cardiolipin, phosphatidylethanolamine, and phosphatidylinositol. Thus, PIMs are quantitatively minor but responsive to environmental stresses in M. smegmatis. Our study paves the way for accurate modeling of mycobacterial plasma membrane.

Quality-by-Design Based Development of Doxycycline Hyclate-Loaded Polymeric Microspheres for Prolonged Drug Release.

This study explores a novel approach to address the challenges of delivering highly water-soluble drug molecules by employing hydrophobic ion-pairing (HIP) complexes within poly (lactic-co-glycolic acid) (PLGA) microspheres. The HIP complex, formed between doxycycline hyclate (DH) and docusate sodium (DS), renders the drug hydrophobic. The development of the microspheres was done using the QbD approach, namely, Box-Behnken Design (BBD). A comprehensive characterization of the HIP complex confirmed the successful conversion of DH. DH and the HIP complex were effectively loaded into PLGA microspheres using the oil-in-water (O/W) emulsion solvent evaporation method. Results demonstrated significant improvements in percentage entrapment efficiency (% EE) and drug loading (% DL) for DH within the HIP complex-loaded PLGA microspheres compared to DH-loaded microspheres alone. Additionally, the initial burst release of DH reduced to 3% within the initial 15min, followed by sustained drug release over 8days. The modified HIP complex strategy offers a promising platform for improving the delivery of highly water-soluble small molecules. It provides high % EE, % DL, minimal initial burst release, and sustained release, thus having the potential to enhance patient compliance and drug delivery efficiency.

Development of surfactant integrated polyaniline based electrode material towards supercapacitor application

Tailoring electrode material is always important for fabricating high-performance energy storage devices. Polyaniline (PANI) is one of the most-explored electrode materials due to its electroactivity, redox property, easy and cost-effective synthesis and reasonable capacitance. Herein, PANI has been integrated with surfactants (cetyltrimethylammonium bromide, dioctyl sodium sulfosuccinate, sodium lauryl sulphate, Tween-80) via chemical oxidative polymerization pathway and utilized as the electrode material for supercapacitor. Chemical nature, crystallinity and morphology of surfactant integrated PANI samples were evaluated by FTIR, UV–Visible, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques while electrochemical properties were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy studies. Among the different PANI samples, PANI integrated with cetyltrimethylammonium bromide (PMC) afforded 2.3 times higher capacitance (528 F/g) than PANI synthesized without surfactants (PM) (229 F/g). Due to the influence of CTAB, PMC displayed higher pore volume and lesser particle size as investigated by Brunauer-Emmett-Teller and dynamic light scattering analyses. Furthermore, PMC displayed two times higher electroactive surface area as compared to PM as investigated by cyclic voltammetry studies. It has been observed that the surfactant not only improved the processability of the polymer but also assisted in enhancing the capacitance of the electrode material significantly.

Fabrication of Oleophilic Polypeptide Nanoparticle from Complexing of Cross-Linked Epsilon-poly-l-lysine with Docusate Sodium for Preparation of Bactericidal Thermoplastic Polyurethanes.

Thermoplastic polyurethanes (TPUs) are extensively utilized in the biomedical field due to their exceptional mechanical properties and biocompatibility. However, the lack of antibacterial activity limits their application ranges. Nanoscopic particle-based additives with inherent antibacterial characteristics are regarded as promising strategies to prevent biomaterials-associated infection. Herein, a novel polymeric nanoparticle is prepared, which integrates chemically cross-linked epsilon-poly-l-lysine (CPL) and anionic surfactant-docusate sodium (DS). The cross-linked epsilon-poly-l-lysine/docusate sodium (CPL/DS) nanoparticle can be well dispersed in organic solvent and a polymer matrix, which is beneficial to endowing TPUs with synergistic miscibility and antibacterial properties. An antibacterial test showed that the CPL/DS nanoparticles have strong antibacterial activity against S. aureus. Moreover, the results of antibacterial experiments in vitro revealed that almost 100% of S. aureus could be killed by CPL/DS nanoparticle-embedded TPU film with a content of 0.5 wt %. In addition, all of the CPL/DS modified TPU films showed good cytocompatibility in vitro. Consequently, this kind of CPL/DS nanoplatform has great potential to serve as a safe and high-efficient bactericidal agent for endowing biomedical devices with bactericidal property.

Effect of different micelles on charging and discharging behavior of phase change material

Phase change material (PCM) offers high-density thermal energy storage, making it attractive for thermal management applications of electronic circuitry and thermal energy storage. However, PCM, like paraffin wax, ideal for such low-temperature applications, has very low thermal conductivity. The present study focused on the improvement of the thermal conductivity of paraffin wax using surfactants. The surfactants used as thermal conductivity enhancers (TCE) are cetyltrimethyl ammonium bromide (CTAB), Dioctyl sodium sulfosuccinate (known as AOT) and sodium dodecyl sulfate (SDS). The surfactant self-aggregation called a micelle, acts as conducting medium inside the paraffin wax, providing better thermal conductivity. The highest heat transfer rate with a peak temperature of 71 °C was observed in the case of AOT micelle paraffin wax. Adding SDS, CTAB, and AOT surfactants increased the highest temperatures by 4%, 8.4%, and 18.33% compared to pure PCM.

Medication Use Evaluation of Docusate Sodium in Constipation Prophylaxis and Opioid Induced Constipation at the WPB VA HCS Community Living Center.

Docusate sodium's efficacy is widely debated. Several studies on opioid induced constipation (OIC) concluded that docusate sodium vs either placebo or in combination with sennosides provided no benefit. This medication use evaluation aimed to investigate constipation treatment trends within the West Palm Beach VA Healthcare System Community Living Center, and to assess the therapeutic effectiveness of docusate sodium. This was a retrospective review of data extracted from April 1, 2022, to September 30, 2022. Patients were included if they had oral orders for docusate sodium, sennosides, lactulose, and/or polyethylene glycol. Patients without active bowel regimen medications were excluded. Requirements for rescue constipation medication was evaluated. A total of 98 patients were reviewed. Docusate sodium was used in 43% (n = 42/98) of patients. Rescue medications were needed in 58% (n = 22/38) of patients receiving oral docusate sodium. 52% (n = 29/56) of patients without docusate sodium required rescue medications. For OIC treatment, when docusate sodium was added to other bowel regimens, 59% (n = 17/29) of patients needed a rescue medication, while 66% (n = 19/29) of patients without docusate sodium required a rescue medication. Patients on morphine were given the greatest quantity of rescue constipation medications (73%, n = 16/22). Oral docusate sodium did not reduce the requirement for rescue constipation medications in the WPB VAHCS CLC population. When evaluating constipation treatment, docusate sodium may supply minimal benefit and could be identified as nonessential for deprescribing efforts. Morphine was the most constipating opioid used in this patient population, requiring more aggressive bowel regimens.

Binding and occupancy properties of gabapentin in mixed surfactant systems

AbstractThis research highlights the efficacy of mixed micellar systems as an innovative chemical formulation for improving the binding properties of active pharmaceutical drugs. The formulations based on the mole fraction were utilized for preparing mixed micelles with anionic sodium dioctyl sulfosuccinate (AOT) and sodium dodecyl sulphate (SDS). DLS measurements demonstrated the formation of small micelles and mixed micelles in SDS‐AOT combinations. A UV absorbance investigation demonstrated the effectiveness of the SDS‐AOT mixed micelles for determining the binding constant (Kb) and mean ion occupancy (i0) of the anticonvulsant gabapentin (GBP) drug. Kb values increased, but the occupancy (i) of GBP per micelle decreased by decreasing the mole fraction (α) of SDS from αSDS 0.9 to 0.1, predicting a shift in occupancy of drugs from the Palisade to the Stern layer. To get a better comprehension of micellization behavior and preferential interaction of the drugs under study, molecular docking studies were performed. According to the docking studies, the GBP displayed significant binding in the presence of SDS‐AOT when compared to pure SDS and AOT molecules. Ultimately, in pharmaceutical applications, mixed micelle played an important role in enhancing the binding and encapsulation efficiency of drugs.

Enhancing the tribological performance of PLA-based biocomposites reinforced with graphene oxide

Poly(lactic acid) (PLA) reinforced with graphene has gained substantial interest as a biomaterial, where the tribological and mechanical behavior of PLA/graphene composites are major concerns. This study aims to develop PLA-based biocomposites reinforced with graphene oxide (GO) that have enhanced tribological capabilities. First, homogenous dispersions of GO and GO treated with the anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) were retained. Then, poly(L-lactic acid) (PLLA) biopolymer and PLLA/GO, PLLA/GO(AOT), PLA/GO(AOT), and PLLA/polyethylene glycol (PEG)/GO biocomposite samples were produced via hot pressing, and their tribological behavior was examined in detail. The worn surface characteristics were examined using scanning electron microscopy (SEM), 3D confocal microscopy, and atomic force microscopy (AFM). Results showed that GO reinforcement considerably affected the sliding wear behavior of PLA. Contrary to anticipated, surface treatment of GO does not improve the PLLA/GO wear resistance; rather, it increases the wear rate. PEG positively affects the sliding wear performance of PLLA/GO. PLLA/GO and PLLA/PEG/GO biocomposites exhibited the lowest wear rate at normal loads of 5 and 8 N, respectively, which was decreased by about 50% compared to unreinforced PLLA samples. With the addition of GO, the wear mechanisms of the PLA-based biocomposites changed from adhesive wear to abrasive wear. These findings might increase the applicability of PLA-based biocomposites where tribological performance is the main concern, such as biodegradable implants for load-bearing bone fractures or scaffolds, opening up new opportunities for their use.

Mucus-penetrating and permeation enhancer albumin-based nanoparticles for oral delivery of macromolecules: Application to bevacizumab

The oral administration of therapeutic proteins copes with important challenges (mainly degradation and poor absorption) making their potential therapeutic application extremely difficult. The aim of this study was to design and evaluate the potential of the combination between mucus-permeating nanoparticles and permeation enhancers as a carrier for the oral delivery of the monoclonal antibody bevacizumab, used as a model of therapeutic protein. For this purpose, bevacizumab was encapsulated in PEG-coated albumin nanoparticles as a hydrophobic ion-pairing complex with either sodium deoxycholate (DS) or sodium docusate (DOCU). In both cases, complex formation efficiencies close to 90% were found. The incorporation of either DS or DOCU in PEG-coated nanoparticles significantly increased their mean size, particularly when DOCU was used. Moreover, the diffusion in mucus of DOCU-loaded nanoparticles was significantly reduced, compared with DS ones. In a C. elegans model, DS or DOCU (free or nanoencapsulated) disrupted the intestinal epithelial integrity, but the overall survival of the worms was not affected. In rats, the relative oral bioavailability of bevacizumab incorporated in PEG-coated nanoparticles as a complex with DS (B-DS-NP-P) was 3.7%, a 1000-fold increase compared to free bevacizumab encapsulated in nanoparticles (B-NP-P). This important effect of DS may be explained not only by its capability to transiently disrupt tight junctions but also to their ability to increase the fluidity of membranes and to inhibit cytosolic and brush border enzymes. In summary, the current strategy may be useful to allow the therapeutic use of orally administered proteins, including monoclonal antibodies.Graphical

Transition from a foam-like to an onion-like nanostructure in water-rich L3 phases

Abstract In dilute water-surfactant systems L3 phases are found in which bilayers interconnect to form a sample-spanning sponge-like structure. From our previous study of the system water/NaCl-AOT (sodium bis(2-ethylhexyl) sulfosuccinate) we know that a transition of this sponge-like structure to an oil-continuous foam-like structure occurs upon addition of minute amounts of oil (about 3 wt%, α = 0.03) in the L3 channel at a constant surfactant mass fraction of γ = 0.15 and T = 25 °C. The aim of the present study was to verify if the same transition occurs at γ = 0.25. To achieve this goal, we determined the relevant part of the phase diagram and studied the electrical conductivities and viscosities within the narrow one-phase L3 channel. Although the electrical conductivities and viscosities change qualitatively like those observed at γ = 0.15 we did not observe a sponge-like structure at γ = 0.25 in the oil-free system (α = 0) with freeze-fracture electron microscopy (FFEM) and freeze fracture direct imaging (FFDI). Together with the FFEM/FFDI images and SANS/SAXS curves we provide experimental evidence for a structural transition with decreasing oil content from a thermodynamically stable foam-like to a thermodynamically stable onion-like nanostructure at γ = 0.25 rather than to a sponge-like structure as is the case at γ = 0.15.

Oral Self-Nanoemulsifying System Containing Ionic Liquid of BX795 Is Effective against Genital HSV-2 Infection in Mice.

BX795 is an emerging drug candidate that has shown a lot of promise as a next-generation non-nucleoside antiviral agent for the topical treatment of herpes simplex virus type-1 (HSV-1) and herpes simplex virus type-2 (HSV-2) infections. Our studies indicated that BX795 has limited oral bioavailability, which could be attributed to its low and pH-dependent solubility. Lipid-based formulations such as self-nanoemulsifying systems (SNESs) can improve the solubility and oral bioavailability of BX795, but the poor lipid solubility of BX795 further limits the development of SNES. To improve the loading of BX795 into SNES, we evaluated the ability of various bulky and biocompatible anions to transform BX795 into an ionic liquid (IL) with higher lipid solubility. Our studies showed that sodium lauryl sulfate and docusate sodium were able to transform BX795 into IL. Compared to pure BX795, the developed BX795 ILs showed differential in vitro cytocompatibility to HeLa cells but exhibited similar in vitro antiviral activity against HSV-2. Interestingly, BX795 docusate (BX795-Doc), an IL of BX795 with ∼135-fold higher lipid solubility than pure BX795, could be successfully incorporated into an SNES, and the developed BX795-Doc-SNES could readily form nanoemulsions of size ≤200 nm irrespective of the pH of the buffer used for dilution. Our in vitro studies showed that BX795-Doc-SNES retained the inherent antiviral activity against HSV-2 and showed similar in vitro cytocompatibility, indicating the availability of BX795 from the SNES in vitro. Finally, orally delivered SNES containing BX795-Doc showed a significant reduction in HSV-2 infection in mice compared to the untreated control. Thus, the transformation of BX795 into IL and the subsequent incorporation of the BX795 IL into the SNES are an effective strategy to improve oral therapy of genital herpes infection.

Impact of Additives on Drug Particles during Liquid Antisolvent Crystallization and Subsequent Freeze-Drying.

The impact of single or combinations of additives on the generation of nanosuspensions of two poorly water-soluble active pharmaceutical ingredients (APIs), fenofibrate (FF) and dalcetrapib (DCP), and their isolation to the dry state via antisolvent (AS) crystallization followed by freeze-drying was explored in this work. Combinations of polymeric and surfactant additives such as poly(vinyl alcohol) or hydroxypropyl methyl cellulose and sodium docusate were required to stabilize nanoparticles (∼200-300 nm) of both APIs in suspension before isolation to dryness. For both FF and DCP, multiple additives generated the narrowest, most-stable particle size distribution, with the smallest particles in suspension, compared with using a single additive. An industrially recognized freeze-drying process was used for the isolation of these nanoparticles to dryness. When processed by the liquid AS crystallization followed by freeze-drying in the presence of multiple additives, a purer monomorphic powder for FF resulted than when processed in the absence of any additive or in the presence of a single additive. It was noted that all nanoparticles freeze-dried in the presence of additives had a flat, flaky habit resulting in large surface areas. Agglomeration occurred during freeze-drying, resulting in micron-size particles. However, after freeze-drying, powders produced with single or multiple additives showed similar dissolution profiles, irrespective of aging time before drying, thus attenuating the advantage of multiple additives in terms of size observed before the freeze-drying process.

Transition from a Sponge-Like to an Onion-Like Nanostructure in the L3 Phase – Part I

HypothesisIn the phase diagram of the system H2O/NaCl – AOT (sodium bis(2-ethylhexyl) sulfosuccinate) a homogeneous L3 channel can be detected at T = 25 °C as a function of the surfactant and the NaCl mass fraction. Our hypothesis is that a structural transition from a sponge-like to an onion-like structure occurs in this channel. ExperimentsWe (a) determined the relevant part of the phase diagram, (b) carried out electrical conductivity and viscosity measurements, (c) visualized the nanostructure with freeze-fracture electron microscopy (FFEM) and freeze fracture direct imaging (FFDI), (d) determined the characteristic length scales from Small Angle Neutron Scattering (SANS) curves. FindingsWe detected a narrow one-phase L3 channel in which the conductivities decrease, while the viscosities increase with increasing surfactant and salt mass fractions. Together with the FFEM/FFDI images and the SANS curves we provide experimental evidence for a structural transition from a sponge-like to an onion-like structure: all structures as well as their coexistences are thermodynamically stable.

Self-emulsifying Drug Delivery Systems (SEDDS) Containing Reverse Micelles: Advanced Oral Formulations for Therapeutic Peptides.

Alternative methods to hydrophobic ion pairing for the formation of lipophilic complexes of peptide drugs to incorporate them in lipid-based nanocarriers such as self-emulsifying drug delivery systems (SEDDS) for oral administration are highly on demand. Such an alternative might be reverse micelles. Within this study, SEDDS containing dry reverse micelles (dRMsPMB ) formed with an anionic (sodium docusate; AOT), cationic (dimethyl-dioctadecyl-ammonium bromide; DODAB), amphoteric (soy lecithin; SL) or non-ionic (polysorbate 85; P85) surfactant loaded with the model peptide drug polymyxin B (PMB) were developed. They were characterized regarding size, payload, release kinetics, cellular uptake and peptide activity. SEDDS exhibited sizes from 22.2 ± 1.7nm (AOT-SEDDS-dRMsPMB ) to 61.7 ± 3.2nm (P85-SEDDS-dRMsPMB ) with payloads up to 2% that were ∼7-fold higher than those obtained via hydrophobic ion pairing. Within 6h P85-SEDDS-dRMsPMB and AOT-SEDDS-dRMsPMB showed no release of PMB in aqueous medium, whereas DODAB-SEDDS-dRMsPMB and SL-SEDDS-dRMsPMB showed a sustained release. DODAB-SEDDS-dRMsPMB improved uptake by Caco-2 cells most efficiently reaching even ∼100% within 4h followed by AOT-SEDDS-dRMsPMB with ∼20% and P85-/SL-SEDDS-dRMsPMB with ∼5%. The peptide drug maintained its antimicrobial activity in all SEDDS-dRMsPMB . According to these results, SEDDS containing dRMs might be a game changing strategy for oral peptide drug delivery. This article is protected by copyright. All rights reserved.

Effect of adjuvants on physicochemical properties of lime sulfur on flower/paraffin and application on flower thinning.

Adjuvants can effectively enhance the utilization rate of pesticides, but the application of adjuvants in plant growth regulators is rarely studied. This work explored the effects of adjuvants dioctyl sulfosuccinate sodium salt (AOT) and methyl oleate (MO) on lime sulfur (LS), especially the drop behavior on flower and paraffin surface. The results showed that the addition of AOT and AOT+MO can significantly reduce the static and dynamic surface tension of LS from 72mN/m to 28mN/m and 32mN/m respectively, and increase the spreading factor from 0.18 to 1.83 and 3.10 respectively, reduce the bounce factor from 2.72 to 0.37 and 0.27 respectively. The fluorescence tracer test showed that the addition of adjuvants could promote the spreading and permeation of droplets. The field test results revealed that the flower thinning rate of adjuvant and non-adjuvant were 80.55% and 54.4% respectively, and the flower thinning effect of adding adjuvant was the same as that of artificial which the flower thinning rate was 84.77%. The quality of apples treated with adjuvants was similar to that treated with artificial, and the weight of single fruit increased by 24.08% compared with CK (spray water). The application of tank-mixture adjuvant could reduce the dosage of LS for thinning agent application, improve apple's quality, and decrease labor cost and improve the economic benefits of fruit planting and the environmental benefits of plant growth regulators.

Antibacterial HPL‐DOSS surface coating for commercial plastics

AbstractBacterial colonization and biofilm formation on the surface of materials can lead to serious bacterial infections and are highly detrimental to our health. Here, we prepared a water‐insoluble HPL‐DOSS complex by compounding hyperbranched polylysine (HPL) with docusate sodium salt (DOSS) and coated HPL‐DOSS onto the surfaces of the commercial polypropylene (PP) and thermoplastic polyurethane (TPU) plastics to afford antibacterial PP‐HD and TPU‐HD plastics. PP‐HD and TPU‐HD showed excellent antibacterial activities against both Escherichia coli and MRSA. In addition, the bacterial residues on the PP‐HD and TPU‐HD surfaces were significantly reduced compared with the pristine PP and TPU surfaces, indicating that the HPL‐DOSS surface coating had good anti‐adhesive property against bacteria and helped to reduce the formation of biofilms. Meanwhile, both PP‐HD and TPU‐HD exhibited excellent biocompatibility, indicating that the HPL‐DOSS complex could be used as a safe antimicrobial coating material to reduce bacterial infections on plastic surfaces.

Observation of Nanoconfinement Effect on the Kinetics of Hydrated Electron in the Nanoscale Water Pools of Water-AOT-Cyclohexane Microemulsions by Picosecond Pulse Radiolysis.

The decay kinetics of the hydrated electron (eaq-) in aerosol OT (AOT)-based ternary microemulsions with pool sizes ranging from 0.34 to 4.85 nm were studied using picosecond pulse radiolysis coupled with transient absorption UV-vis spectroscopy. Electron transfer from oil to water and the subsequent solvation occurred within a time resolution of 7 ps. The decay kinetics of eaq- were accurately modeled using a double-exponential decay model, revealing the occurrence of two types of reactions, i.e., the recombination reaction at the water-oil interface and the radical-radical reactions in the water pools. The apparent lifetimes of both types of decays decreased significantly as the size of water pools decreased, indicating the influence of nanoconfinement effects. Moreover, the importance of the water-oil interface increased with decreasing water content, regardless of the presence or absence of NO3- as an electron scavenger in the water pools. Our findings provide a comprehensive understanding on the kinetics of the radiation reaction in AOT-based microemulsions.

Enhancing Structural and Thermal Properties of Poly(lactic acid) Using Graphene Oxide Filler and Anionic Surfactant Treatment.

Graphene has attracted extensive attention in various fields due to its intriguing properties. In this work, nanocomposite films based on poly(lactic acid) (PLA and PLLA) polymers filled with graphene oxide (GO) were developed. The impact of treating GO with the anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) on the properties of the resulting nanocomposites was investigated. To determine the morphological, optical, and structural properties of the obtained materials, physicochemical analyses were performed, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) analysis. Additionally, the thermal properties and wettability of neat polymers and nanocomposites were thoroughly investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and contact angle analysis. It was observed that GO was well dispersed throughout the PLA and PLLA matrix, leading to stronger interface bonding. The results demonstrate that the untreated and treated GO improved the crystallinity and thermal stability properties of the PLA and PLLA. However, the AOT-treated GO has significantly higher performance compared to the untreated GO in terms of crystallinity, melting temperature (increased by ~15 °C), and wettability (the contact angle decreased by ~30°). These findings reveal the high performance of the developed novel composite, which could be applied in tissue engineering as a scaffold.