Towards improving the biocompatibility of prosthetic eyes

Prosthetic eyes are currently manufactured using Poly(methyl methacrylate) (PMMA) which is not an ideal material because it is hydrophobic. While significant research has investigated the benefits of hydrophilic materials for contact lenses, no such research has been carried out on hydrophilic materials for prosthetic eyes until now. In this study, different derivatives of Poly(ethylene glycol) (PEG) monomer and methyl methacrylate (MMA) monomer were grafted to PMMA using copolymerisation. The resulting matrixes were evaluated by water contact angle measurement, 24 h water absorption testing, and colour-difference measurement when exposed to ultraviolet light. The contact angle and water absorption results indicated that ethylene glycol dimethacrylate (EGDMA) grafted PMMA matrix had a better hydrophilic performance than the other matrixes tested. EGDMA is already a minor constituent of the PMMA matrix currently used for manufacturing prosthetic eyes but when the proportion of EGDMA monomer to MMA monomer used in the manufacturing process was increased to 50/50 the hydrophilicity of the matrix was significantly improved. EGDMA-grafted PMMA is inexpensive and comes as a liquid monomer that is easily mixed with the PMMA monomer that ocular prosthetists are familiar with. The mixture requires no special handling beyond the normal safety precautions that apply when using PMMA monomers. In-vitro testing shows that EGDMA-grafted PMMA significantly improves the wettability of PMMA currently used for the manufacture of prosthetic eyes and has the potential to significantly improve wearing comfort and socket health.

Fabrication and Characterization of Black GaAs Nanoarrays via ICP Etching

GaAs nanostructures have attracted more and more attention due to its excellent properties such as increasing photon absorption. The fabrication process on GaAs substrate was rarely reported, and most of the preparation processes are complex. Here, we report a black GaAs fabrication process using a simple inductively coupled plasma etching process, with no extra lithography process. The fabricated sample has a low reflectance value, close to zero. Besides, the black GaAs also displayed hydrophobic property, with a water contact angle of 125°. This kind of black GaAs etching process could be added to the fabrication workflow of photodetectors and solar cell devices to further improve their characteristics.

Exploring the perspective of nano-TiO2 in hydrophobic modified cationic flocculant preparation: Reaction kinetics and emulsified oil removal performance

To reduce the polymerization difficulty of hydrophobic modified copolymers, a hydrophobic modified cationic flocculant was fabricated using nano-TiO₂ as initiator with acrylamide (AM) and methyl acryloxyethyl dimethyl benzyl ammonium chloride (DML) as monomers, and named it PAD. The copolymers were characterized by scanning electron microscopy (SEM), nuclear magnetic resonance (¹H NMR), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TG). Results verified that PAD was synthesized successfully and nano-TiO₂ was more conducive to DML grafting than traditional photo-initiators. Reaction kinetics demonstrated that the polymerization process was a typical precipitation polymerization initiated by free radicals. Flocculation performance of flocculant on simulated emulsified oil was evaluated and optimized. The simulation results indicated that the flocculation performance of PAD was superior to traditional flocculant, which was attributed to the higher content of DML in PAD. The maximum removal rate of emulsified oil could reach 92.10%, and the corresponding turbidity removal rate was 93.54%. Further, the mechanism studies suggested that the removal of emulsified oil was realized by the synergistic effects of electric neutralization, demulsification, hydrophobic association and adsorption bridging. The findings of this study showed that nano-TiO₂ exhibited a promising prospect in the field of polymer-initiated polymerization.

Analysis of YAG Laser-Induced Damage in Intraocular Lenses: Characterization of Optical and Surface Properties of YAG Shots

PURPOSE

To assess differences in neodymium:yttrium aluminum garnet (Nd:YAG)-induced defects in hydrophilic and hydrophobic intraocular lenses (IOLs) and describe optical and surface properties of YAG shots/pitting. Describing and measuring the iatrogenic produced defects should achieve higher awareness on this topic and change the mindset of such a trivial procedure to be proceeded with more caution and calmness in the future.

MATERIALS

Twelve IOLs from different manufacturers made of hydrophilic and hydrophobic materials were evaluated before and after treatment with the Nd:YAG laser. Microscopy and environmental scanning electron microscopic (ESEM) images were used to visually analyze the defects. Additionally, wavefront measurements were taken for power mapping and Raman spectroscopy was performed. Vertical and horizontal dimensions of the defects were analyzed and compared, and Raman line scans assessed the changes in the chemical structure in the defect area of the IOL.

RESULTS

Microscopically, pitting of the surface could be observed in both lens types. Defects in hydrophobic lenses appeared bigger and were visible with less magnification than in hydrophilic lenses. Similar results were obtained with ESEM images where the defects in hydrophobic IOLs seemed to be frayed while defects in hydrophilic IOLs were of circular shape. Raman spectroscopy revealed deeper defects in hydrophobic lenses. Vertical dimensions of the defects were statistically significant (p = 0.036) and greater in hydrophobic materials while horizontal dimensions did not reach significance (p = 0.056). The area of chemical changes was greater than the visible defect area and smaller in hydrophilic than that in hydrophobic materials.

CONCLUSION

Nd:YAG seems to have greater impact on hydrophobic IOL materials as that damage was greater and more frayed than that in hydrophilic materials. Moreover, there seems to be larger, distinctive damage area in IOLs (with chemical changes in the material) than that is visually recognizable. Therefore, a very cautious approach is recommended when performing capsulotomy, as defects in the surface structure can occur. This might come along with problems in quality of vision in monofocal and primarily premium IOLs (multifocal, enhanced depth of focus, and toric IOLs), dependent on the size, dimension, and position in the IOL. YAG capsulotomy should not be considered trivial but should be carried out with precision and without time pressure, just like surgery itself.

Construction of a hydrophobic magnetic aerogel based on chitosan for oil/water separation applications

Hydrophobic/oleophilic absorbents have been largely studied and used in recovering spilled oil. However, they still suffer from several drawbacks and two of them are poor biocompatibility and hard to thoroughly rinse. In order to address these problems, here a hydrophobic magnetic chitosan-based aerogel is fabricated via electrostatic interactions between chitosan (CS), itaconic acid (IA) and Fe₃O₄ nanoparticles and dip-coating in ethanol solution of Candelilla wax (CW). Due to the interconnected porous structure of chitosan-based aerogel, the magnetism of Fe₃O₄ nanoparticles and the hydrophobicity of CW, the prepared aerogel exhibits high absorption capacities (from 17.7 to 43.8 g/g) towards various types of organic liquids, excellent magnetic controllability with saturation magnetization of 15.93 emu/g and good water repellency with water contact angle (WCA) of 147.9°. In addition, the aerogel can also continuously separate immiscible oil/water mixtures and water-in-oil emulsions as the form of filter. More significantly, the absorbed organic liquids can be completely recovered by simply placing the aerogel in water solution of IA at 75 °C, which can avoid cleaning agent consumption. As a consequence, this renewable, biodegradable and eco-friendly oil scavenger presents a bright prospect in practical applications.

Growth of centimeter-scale perovskite single-crystalline thin film via surface engineering

Modern electronic and photonic devices rely on single-crystalline thin film semiconductors for high performance and reproducibility. The emerging halide perovskites have extraordinary electronic and photonic properties and can be synthesized via low cost solution-based methods. They have been used in a variety of devices with performance approaching or over the devices based on conventional materials. However, their solution based growth method is intrinsically challenge to grow large scale single-crystalline thin film due to the random nucleation and isotropous growth of the crystal. Here, we report the growth of centimeter-scale perovskite single-crystalline thin films by controlling the nucleation density and growth rate of the crystal under a spatially confined growth condition. The hydrophobic treatment on substrates inhibits nucleation and accelerates the growth of single-crystalline thin film, providing enough space for initial nucleus growing up quickly without touching each other. Single-crystalline perovskite thin-film with an aspect ratio of 1000 (1 cm in side length, 10 μm in thickness) has been successfully grown. The low trap density and the high mobility of the as-grown thin film show a high crystallinity. The photodetector based on the perovskite thin film has achieved a gain ~ 104, benefitting from the short transit time of the carries due to the high mobility and thin thickness of the active layer. Our work opens up a new route to grow large scale perovskite single-crystalline thin films, providing a platform to develop high- performance devices.

Preparation and characterization of highly transparent hydrophobic nanocellulose film using corn husks as main material

In this paper, nanocellulose was extracted from agricultural waste corn husks. Transparent hydrophobic membranes containing silica were fabricated through two facile methods including surface coating and internal grafting. The results showed that: the nanocellulose prepared by TEMPO-mediated oxidation and high pressure homogenization not only retained the type and crystal structure of the original cellulose, but also increased the crystallinity to 64.5% and improved the thermal stability. Both surface coating and internal grafting methods had successfully loaded silica onto films. The internal grafting film had a silica content of 10.5%, which was mainly present inside the film. The light transmittance of this film was 84.4% and the surface contact angle to water was 152.6°. The content of silica on the surface coating film was 5.7%, and they were mainly distributed on the surface of the film to form a nano-scale rough surface. The light transmittance of the surface coating film was 87.8% and the surface contact angle to water was 165.7°. Compared to the film prepared by internal grafting method, the nanocellulose film prepared by surface coating method contained less nano silica and had better properties including higher transparency, higher surface roughness and excellent hydrophobic anti-fouling properties.

LHRH-conjugated, PEGylated, poly-lactide-co-glycolide nanocapsules for targeted delivery of combinational chemotherapeutic drugs Docetaxel and Quercetin for prostate cancer

One of the major challenges in effective cancer chemotherapy is the severe systemic cytotoxicities of anticancer drugs on healthy tissues. The present study reports chemically modified polymeric nanocapsules (NCs) encapsulating combination of chemotherapeutic drugs Docetaxel (DTX) and Quercetin (QU) for its active targeting to prostate cancer (PCa). The active targeting was achieved by conjugating Luteinizing-hormone-releasing hormone (LHRH) ligand to poly-lactide-co-glycolide (PLGA) using polyethylene glycol (PEG) as a spacer. The structure of the conjugates was characterized and confirmed using ¹H NMR and ATR-FTIR. The drug encapsulated NCs showed a homogenous size distribution with their size ranging between 120 and 150 nm, and exhibited a negative zeta potential in the range of -20 to -40 mV. The in vitro release studies highlighted the sustained drug release pattern from the respective NCs; while the PEG coating to polymeric NCs provided serum stability to the NCs. The in vitro biological evaluation of the NCs was conducted using PC-3 and LNCaP cell lines. The results of the cellular uptake studies showed a significantly higher untake of the LHRH targeted NCs, while the LHRH-targeted-PEGylated DTX: QU NCs exhibited higher caspase-3 activity. The cell viability assay results showed the enhanced cell inhibition activity of the combinatorial DTX: QU when compared to individual DTX. Further, higher cell cytotoxicity was achieved by LHRH-targeted DTX: QU NCs as compared to their free-form or non-targeted NCs. Finally, the results of in vivo tumor localization and in vivo antitumor activity studies complimented and upheld the in vitro results, demonstrating the beneficial role of PLGA-PEG-LHRH NCs encapsulating combination of DTX and QU in combating prostate cancer (PCa).

Trophic magnification of legacy persistent organic pollutants in an urban terrestrial food web

Legacy persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), persist for generations in the environment and often negatively impact endocrine functions in exposed wildlife. Protocols to assess the bioaccumulation potential of these chemicals within terrestrial systems are far less developed than for aquatic systems. Consequently, regulatory agencies in Canada, the United States, and the European Union rely primarily on aquatic information for the bioaccumulation assessment of chemicals. However, studies have shown that some chemicals that are not bioaccumulative in aquatic food webs can biomagnify in terrestrial food webs. Thus, to better understand the bioaccumulative behaviour of chemicals in terrestrial systems, we examined trophic magnification of hydrophobic POPs in an urban terrestrial food web that included an avian apex predator, the Cooper's hawk (Accipiter cooperii). Over 100 samples were collected from various trophic levels of the food web including hawk eggs, songbirds, invertebrates, and berries and analysed for concentrations of 38 PCB congeners, 20 OCPs, 20 PBDE congeners, and 7 other brominated flame retardants listed on the Government of Canada's Chemicals Management Plan. We determined trophic magnification factors (TMFs) for contaminants that had a 50% or greater detection frequency in all biota samples and compared these terrestrial TMFs to those observed in aquatic systems. TMFs in this terrestrial food web ranged between 1.2 (0.21 SE) and 15 (4.0 SE), indicating that the majority of these POPs are biomagnifying. TMFs of the legacy POPs investigated in this terrestrial food web increased in a statistically significant relationship with both the logarithm of the octanol-air (log K_OA) and octanal-water partition (log K_OW) coefficients of the POPs. POPs with a log K_OA >6 or a log K_OW >5 exhibited biomagnification potential in this terrestrial food web.

Aqueous biphasic systems formed by hydrophilic and hydrophobic deep eutectic solvents for the partitioning of dyes

Two kinds of hydrophobic deep eutectic solvents (DESs), including hexafluoroisopropanol (HFIP)-based DESs and polypropylene glycol 400 (PPG400)-based DESs, were synthesized to construct aqueous biphasic systems (ABSs) with choline chloride (ChCl)-based hydrophilic DESs for the first time, respectively. Three kinds of dyes with different hydrophobicity, including tartrazine, methylene blue and sudan Ⅲ, were chosen as the target analytes to evaluate the partitioning behaviors of the DES/DES ABSs. The effect of the types of hydrophilic DESs on dyes extraction were investigated and ChCl-glycol (ChCl-G) was selected as the phase-forming component. Then the partitioning of dyes in diverse DES/DES ABSs with different hydrophobicity was addressed by altering the carbon chain length of hydrogen bond accepter (HBA) in hydrophobic DES and changing the molar ratio of HBA: hydrogen bond donor (HBD) in hydrophilic DES. The results proved that in the ABSs of HFIP-based DES/DES, the sudan Ⅲ tended to migrate to the hydrophobic DES-rich phase with the increased carbon chain length of hydrophobic DES and was inclined to transfer to the hydrophilic DES-rich phase with the increasing proportion of G in ChCl-G. Afterwards, the methylene blue was chosen to explore the influence factors of the extraction process. And the results showed that the adjusting of pH value could achieve a complete opposite distribution of methylene blue in PPG400-based DES/DES ABSs. Besides, extraction of dyes in real samples were evaluated and recoveries of 92.3%-106.1% were achieved. Moreover, the analysis of mixed samples demonstrated that 88.64% of tartrazine and 92.63% of methylene blue were enriched into the hydrophilic phase, while nearly all of the sudan Ⅲ was moved into the hydrophobic phase. In addition, the phase-forming components could be reused according to the regeneration studies. Method validation proved the good precision, repeatability and stability of the established method. At last, the extraction mechanism was further investigated by dynamic light scattering (DLS) and transmission electron microscope (TEM). It turned out the formation of DES-dye aggregates might be responsible for the separation process. Above all, the results highlighted the possibility of the DES/DES ABSs as tunable systems for the partitioning of dyes with different hydrophobicity.

An Advanced Fiber-Reinforced Composite Solution for Gingival Inflammation and Bone Loss Related to Restorative Crowns

Soaring gold prices have created an almost impossible void in the Dental Materials supply reserves for affordable patient posterior crowns. Fortunately, aerotech fiber-reinforced composite (FRC) materials in use for many diverse structural applications can be developed for dentistry to replace gold with computer-assisted design/computer-assisted manufacture (CAD/CAM) technology. Current dental ceramics or high-strength oxide ceramics like alumina and zirconia available for CAD/CAM have extremely poor fracture-toughness properties and can propagate microscopic cracks rapidly to sudden adverse brittle failure. As a highly promising alternative, exceptional FRC fracture toughness properties counteract brittle failure with high-strength fibers that act as major barriers to crack propagation. In addition, excellent rapid FRC CAD/CAM machining can offer one-patient appointments for single crowns. FRCs have high-strength fibers coupled into a polymer matrix with the ability to form strong covalent bonds with resin adhesives whereas ceramics do not bond well and oxide ceramics have non-reactive inert surfaces making resin bonding extremely difficult. Prominent adhesive free-radical covalent bonding by FRCs then provides a great opportunity to achieve a crown marginal reline directly on the patienťs clinical tooth for possible near zero-gap defect tolerances. To place crown gingival marginal defects in proper perspective, gaps between the tooth and crown expose luting cements that can wash out and provide space for microbial plaque growth. Bacterial toxins released from a crown-tooth interface can subsequently produce secondary decay, gingival inflammation and eventually under severe plaque environments breed periodontal disease with bone loss.

Blending of phthalated starch and surface functionalized rice husk extracted nanosilica with LDPE towards developing an efficient packaging substitute

Starch was transformed to hydrophobic starch phthalate (contact angle 109°) in order to achieve a good dispersion in LDPE matrix. Nanosilica derived from rice husk after aminopropyltrimethoxysilane functionalization was also incorporated into the blend as property-enhancing filler. The produced crystalline starch phthalate had a lower particle size of 9.87 μm and a higher surface area of 2.87 m²/g compared to starch (40.28 μm, 1.91 m²/g). The potential quality modification of starch phthalate as a substitute for starch towards the production of a perfect biodegradable blend was quantified in terms of mechanical (tensile, tear, stiffness), optical (haze, transmittance), and biodegradation assessments. Interfacial adhesion between LDPE and starch phthalate was well justified by the morphology and enhancement in mechanical properties like tensile and tear strength from 8.87 to 12.67 MPa and 96.57 to 187.10 N/mm for 30% of starch or starch phthalate in LDPE matrix, respectively. Starch phthalate compared to starch blended films showed a higher biodegradation rate of 14.8 and 13.5% in garden soil and vegetable waste respectively in 1 year (at 30% biofiller), with a good first-order kinetics fit of the weight loss data having a higher degradation rate constant at higher content of biofiller in the blend.

Cholesterol-modified lignin: A new avenue for green nanoparticles, meltable materials, and drug delivery

Two fractions of kraft lignin of low and high molecular weight were reacted with cholesteryl chloroformate (Chol.Cl) to produce a modified lignin that demonstrated very high hydrophobicity. Surprisingly, both fractions displayed discernible melting points as opposed to the starting lignin. The suspension in water also gave rise to nanoparticles that displayed sizes in the range of 200-500 nm that were shown to satisfactorily load and release folic acid, a representative hydrophobic molecule, within the context of drug delivery.

Moderate-temperature catalytic incineration of cooking oil fumes using hydrophobic honeycomb supported Pt/CNT catalyst

Catalytic incineration is one of the cost-effective technologies to deal with odor cooking oil fumes (COFs). Hydrophobic carbon nanotubes (CNT) supported Pt catalysts were prepared by incipient wetness impregnation method. The 2.0 wt.%Pt/CNT catalyst gave the highest activity with the lowest light-off temperature near 200 °C. The catalyst was further coated on the carbonized honeycomb which offered low-pressure drop and high surface area per unit volume. Toward feasibility application, hydrophobic honeycomb supported Pt/CNT catalyst achieved an excellent catalytic performance with the conversion of 88.0-91.3 % in gas hourly space velocity (GHSV) ranging from 5,700 to 17,200 h^-1 at 300 °C. Importantly, the honeycomb supported Pt/CNT catalyst could remove COFs substantially under simulated cooking conditions. Only a slight amount of heptane remained after catalytic incineration. In addition, the honeycomb support used much less Pt/CNT catalyst by maintaining the same performance, compared with powder catalyst. Our research outcome provides an excellent opportunity to apply the honeycomb supported Pt/CNT catalyst for moderate-temperature catalytic incineration of odor exhaust from kitchen hood.

Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions

Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4'-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption-desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory-Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract.

Hydrophobic nano sponge for efficient removal of diesel fuel from water and soil

Diesel fuel (DF)-contamination remediation has aroused increasing concern in environmental field. In our work, nano sponge was modified by silylation of amino silicon oil (ASO) and aminopropyltriethoxysilane (APTES) to obtain hydrophobic nano sponge (SPAA). SPAA possessed a micro/nano network structure and could efficiently adsorb DF through hydrophobic polysiloxane group. The results revealed that SPAA could effectively remove DF and control its migration in water and soil under various conditions. Importantly, SPAA could inhibit the harmful effect of DF on the growth of plants, earthworms, and fish. Therefore, this work provides a promising and low-cost approach for removal of DF from water and soil, which might have a potential application value.

Preparation of hydrophobic La2Mo2O9 ceramics with antibacterial and antiviral properties

After powder of La₂Mo₂O₉ (LMO) was prepared using complex polymerization, dense sintered bodies (96% relative density) of LMO were obtained from the powder through pressureless sintering in a synthesized air atmosphere. The water contact angle of the LMO ceramics increased gradually during storage in ambient air. It reached 93.6 ± 3.0° in 624 h. Results of XPS analysis and ozone treatment suggest that organic substances in ambient air adsorbed onto the LMO surface during storage. Measurements of antibacterial (Escherichia coli and Staphylococcus aureus) and antiviral (bacteriophage Qβ and bacteriophage Φ6) activities of LMO revealed that their survival rates decreased more than 99.9% within 6 h. Based on results obtained using dissolved ion contact method and from comparison of the antibacterial and antiviral activities with La₂O₃ and MoO₃, one can infer that the synergistic effect of La₂O₃ and MoO₃ plays an important role in the high antibacterial and antiviral activity of LMO.

Interpenetrating polymer network-based nanocomposites reinforced with octadecylamine capped Cu/reduced graphene oxide nanohybrid with hydrophobic, antimicrobial and antistatic attributes

Designing of mechanically tough elastomeric materials encompassed with intrinsic surface hydrophobicity, antistatic and antimicrobial attributes is in skyrocketing demands, especially to protect the instruments which are submerged in water. Herein, the authors depicted the fabrication of interpenetrating polymer network-based nanocomposites containing different doses of octadecylamine capped Cu/RGO nanohybrid. The structures and morphologies of the synthesized nanohybrid and the fabricated nanocomposites were characterized by using FTIR, XRD, XPS, TGA, FESEM and TEM analyses. Most interestingly the nanocomposites showed good hydrophobicity (static contact angle: 119.2°-129.3°), low surface resistivity (~10⁷ Ω m) and strong antimicrobial activity towards Gram negative (Pseudomonas aeruginosa and Yersinia pestis) and Gram positive (Bacillus cereus) bacterial strains. The fabricated nanocomposites also exhibited antifungal (Candida albicans) activity. In addition, the fabricated nanocomposites showed excellent mechanical properties including high tensile strength (14.03-20.9 MPa), outstanding flexibility (1887-2470%), excellent toughness (249.89-510.1 MJ.m^-3), high scratch resistance (>10 kg) and high thermostability (281-288 °C). Therefore, the fabricated nanocomposites can be used as an effective thin film for many advanced applications.

Site-Specific Labeling of DNA via PCR with an Expanded Genetic Alphabet

The polymerase chain reaction (PCR) is a universal and essential tool in molecular biology and biotechnology, but it is generally limited to the amplification of DNA with the four-letter genetic alphabet. Here, we describe PCR amplification with a six-letter alphabet that includes the two natural dA-dT and dG-dC base pairs and an unnatural base pair (UBP) formed between the synthetic nucleotides dNaM and d5SICS or dTPT3 or analogs of these synthetic nucleotides modified with linkers that allow for the site-specific labeling of the amplified DNA with different functional groups. Under standard conditions, the six-letter DNA may be amplified with high efficiency and with greater than 99.9% fidelity. This allows for the efficient production of DNA site-specifically modified with different functionalities of interest for use in a wide range of applications.

Novel lavender oil and silver nanoparticles simultaneously loaded onto polyurethane nanofibers for wound-healing applications

Synthetic polymers, especially those with biocompatible and biodegradable characteristics, may offer effective alternatives for the treatment of severe wounds and burn injuries. Ideally, the scaffold material should induce as little pain as possible, enable quick healing, and direct the growth of defect-free epidermal cells. The best material with this multifunctionality, such as self-healing dressings, should be hydrophilic and have uninterrupted and direct contact with the damaged tissue. In addition, the ideal biomaterial should have some antibacterial properties. In this study, a novel technique was used to fabricate composite electrospun wound-dressing nanofibers composed of polyurethane encasing lavender oil and silver (Ag) nanoparticles (NPs). After electrospinning, the fabricated nanofibers were identified using various techniques, including scanning electron microscopy (SEM) and transmission electron microscopy (TEM). An abundance of Ag NPs in the fibers decreased the diameter of the fibers while increased concentration of the lavender oil increased the diameter. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) studies showed the presence of the lavender oil and Ag NPs in the fiber dressings. The Ag NPs and lavender oil improved the hydrophilicity of the nanofibers and ensured the proliferation of chicken embryo fibroblasts cultured in-vitro on these fiber dressings. The antibacterial efficiency of the nanofiber dressings was investigated using E. coli and S. aureus, which yielded zones of inhibition of 16.2 ± 0.8 and 5.9 ± 0.5 mm, respectively, indicating excellent bactericidal properties of the dressings. The composite nanofiber dressings have great potential to be used as multifunctional wound dressings; offering protection against external agents as well as promoting the regeneration of new tissue.

Environmentally benign non-wettable textile treatments: A review of recent state-of-the-art

Among superhydrophobic materials, non-wettable textiles are probably the ones that come in contact or interact with the human body most frequently. Hence, textile treatments for water or oil repellency should be non-toxic, biocompatible, and comply with stringent health standards. Moreover, considering the volume of the worldwide textile industry, these treatments should be scalable, sustainable, and eco-friendly. Due to this awareness, more and more non-wettable textile treatments with eco-friendly processes and green or non-toxic chemicals are being adopted and reported. Although fluorinated alkylsilanes or fluorinated polymers with C8 chemistry (with ≥ 8 fluorinated carbon atoms) are the best performing materials to render textiles water or oil repellent, they pose substantial health and environmental problems and are being banned. For this reason, water/solvent-borne, C8-free vehicles for non-wettable treatment formulations are probably the only ones that can have commercialization prospects. Hence, researchers have come up with a variety of new, non-toxic, green formulations and materials to render fabrics liquid repellent that constitute the focus of this review paper. As such, this review article discusses and summarizes recent developments and techniques on various sustainable superhydrophobic treatments for textiles, with comparable performance and durability to formulations based on fluorinated C8 compounds. The current state-of-the-art technologies, potential commercialization prospects, and relevant limitations are discussed and summarized with examples. The review also attempts to indicate promising future strategies and new materials that can transform the process for non-wettable textiles into an all-sustainable technology.

Hazardous waste dewatering and dry mass reduction through hydrophobic modification by a facile one-pot, alkali-assisted hydrothermal reaction

Hazardous waste dewatering is important for volume reduction and further treatment. Hazardous organic wastes with low ratio of free to bound water, and low flash point are difficult to dewater and pose an explosion risk for conventional thermal drying. Here, we develop a facile one-pot, alkali-assisted hydrothermal treatment (AHT) method for cost-efficient hazardous waste dewatering, dry mass minimization and volume reduction. Wet paint sludge (WPS), a hazardous organic waste, was reduced (79% by total weight and 52% by dry mass) by dewatering through AHT hydrophobic modification, and the product was nonflammable. Conversion of bound water to free water enhanced WPS dissolution for further decomposition. Alkali was critical for boosting ether demethylation in the solid phase, and cleavage of ethers forming alcohols that facilitated transfer of solid mass into the liquid phase. Polar functional groups were eliminated through AHT, which increased the relative abundance of hydrophobic functional groups on the surface of solid residues and promoted dewatering. We also demonstrate that AHT can be widely adapted and scaled up to treat various hazardous organic waste streams, which is of significant industrial and environmental interest.

Tunable surface adsorption and wettability of candle soot coated on ferroelectric ceramics

A ferroelectric Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) ceramic was prepared using a solid-state reaction route. A coating of candle soot was provided on poled and unpoled BCZTO samples. X-ray diffraction and Raman spectroscopy confirmed the presence of the graphite form of carbon in the candle soot. Scanning Kelvin probe microscopy determined that the highest surface potentials were ∼34 mV and 1.5 V in the unpoled and poled BCZTO samples, respectively. The candle soot was found to adsorb ∼65%, 80%, and 90% of the methylene blue dye present in acidic, neutral, and basic media, respectively, within 3 h. In both the poled and unpoled cases, the BCZTO samples coated with candle soot showed greater adsorption capacities than the uncoated BCZTO sample. In the cases of poled samples coated with candle soot, the adsorption was found to be greater in the case of candle soot coated on a positively charged surface than that for candle soot coated on a negatively charged BCZTO surface in an acidic medium. In a basic medium, the adsorption was found to be greater in the case of candle soot coated on a negatively charged surface than that for candle soot coated on a positively charged BCZTO surface. The contact angle of the candle soot-coated BCZTO sample was found to be hydrophobic (∼149°). The contact angle decreased (∼149-133°) with an increase in temperature (30-70 °C) in the case of candle soot coated on the positive surface of a poled BCZTO sample. The contact angle increased (∼139-149°) with an increase in temperature (30-70 °C) in the case of candle soot coated on the negative surface of a poled BCZTO sample. Internal electric field-assisted (associated with ferroelectric materials) adsorption could be a potential technique to improve adsorption processes.

Physical characteristics of nano-Hydroxyapatite Pickering-emulsions and their adjuvant activity on the antibody response towards the Bothros asper snake venom

Emulsions are crucial in the treatment of snake bites to bust the antibody response of the inmunogen. The widely used Freund's emulsion typically combines 50/50 water-oil (W/O) phase. However, its use is limited because it is associated with tissue damage. We formulated and characterized a Pickering Emulsion 70/30 (W/O) that uses a chemically modified hydrophobic hydroxyapatite as surfactant. This Pickering emulsion has similar rheologic behavior to Freund's emulsion 50/50, but with lower oil and surfactant concentration. Evaluation of cell recruitment, antibody response and adhering tissue in mice immunized with B. asper of Pacific venom and treated with Freund's and Pickering 70/30 emulsions resulted in similar adjuvant activity (only 18% lower in Pickering 70/30 emulsion). However, Pickering 70/30 emulsions minimized negative side effects in the host animals and showed better ease of flow that favors injection of the host. Our results open up room for optimization and improvement of Pickering emulsion based on modified nanoparticles for medical applications.

Mammalian cell viability on hydrophobic and superhydrophobic fabrics

Surface properties like hydrophobicity and morphology of the substrate are essential for cell proliferation affecting its growth, survival and also for its communication with other cells on fabrics. The combination of low surface energy and a specific surface morphology (micro/nano-roughness) leads to significantly less wettable surfaces, known as superhydrophobic characterized by high contact angle above 150° and a very small hysteresis. Such high water repellent coatings feature small area available to be exploited in many applications where interactions with aqueous environment are strongly to be avoided. In this work, the authors have investigated the influence of coating polyester fabric at different degree of hydrophobicity by mixed organic-inorganic coating with moderated to highly water repellence. Depending on the coating composition and structure, the hydrophobicity of the fabric can be finely modulated by an easy-to-prepare method applicable to commercial, low cost fabric substrates providing advanced performance. In vitro experiments have been performed in order to establish the influence of surface modification on adhesion of representative model mammalian cell lines such as 3T3 fibroblasts, HaCaT keratinocytes and HeLa epithelial carcinoma cells. The obtained results suggested that, in addition to the chemistry and morphology of the coating, the characteristics of the substrate are important parameters on the final cell viabilities.